Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 2989 insertions, 0 deletions

diff --git a/src/vlib/unix/cli.c b/src/vlib/unix/cli.c
new file mode 100644
index 00000000000..69fca6ec7bc
--- /dev/null
+++ b/src/vlib/unix/cli.c
@@ -0,0 +1,2989 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * cli.c: Unix stdin/socket CLI.
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+/**
+ * @file
+ * @brief Unix stdin/socket command line interface.
+ * Provides a command line interface so humans can interact with VPP.
+ * This is predominantly a debugging and testing mechanism.
+ */
+/*? %%clicmd:group_label Command line session %% ?*/
+/*? %%syscfg:group_label Command line session %% ?*/
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vppinfra/timer.h>
+
+#include <ctype.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <termios.h>
+#include <signal.h>
+#include <unistd.h>
+#include <arpa/telnet.h>
+#include <sys/ioctl.h>
+
+/** ANSI escape code. */
+#define ESC "\x1b"
+
+/** ANSI Control Sequence Introducer. */
+#define CSI ESC "["
+
+/** ANSI clear screen. */
+#define ANSI_CLEAR      CSI "2J" CSI "1;1H"
+/** ANSI reset color settings. */
+#define ANSI_RESET      CSI "0m"
+/** ANSI Start bold text. */
+#define ANSI_BOLD       CSI "1m"
+/** ANSI Stop bold text. */
+#define ANSI_DIM        CSI "2m"
+/** ANSI Start dark red text. */
+#define ANSI_DRED       ANSI_DIM CSI "31m"
+/** ANSI Start bright red text. */
+#define ANSI_BRED       ANSI_BOLD CSI "31m"
+/** ANSI clear line cursor is on. */
+#define ANSI_CLEARLINE  CSI "2K"
+/** ANSI scroll screen down one line. */
+#define ANSI_SCROLLDN   CSI "1T"
+/** ANSI save cursor position. */
+#define ANSI_SAVECURSOR CSI "s"
+/** ANSI restore cursor position if previously saved. */
+#define ANSI_RESTCURSOR CSI "u"
+
+/** Maximum depth into a byte stream from which to compile a Telnet
+ * protocol message. This is a saftey measure. */
+#define UNIX_CLI_MAX_DEPTH_TELNET 24
+
+/** Unix standard in */
+#define UNIX_CLI_STDIN_FD 0
+
+
+/** A CLI banner line. */
+typedef struct
+{
+  u8 *line;	/**< The line to print. */
+  u32 length;	/**< The length of the line without terminating NUL. */
+} unix_cli_banner_t;
+
+#define _(a) { .line = (u8 *)(a), .length = sizeof(a) - 1 }
+/** Plain welcome banner. */
+static unix_cli_banner_t unix_cli_banner[] = {
+  _("    _______    _        _   _____  ___ \n"),
+  _(" __/ __/ _ \\  (_)__    | | / / _ \\/ _ \\\n"),
+  _(" _/ _// // / / / _ \\   | |/ / ___/ ___/\n"),
+  _(" /_/ /____(_)_/\\___/   |___/_/  /_/    \n"),
+  _("\n")
+};
+
+/** ANSI color welcome banner. */
+static unix_cli_banner_t unix_cli_banner_color[] = {
+  _(ANSI_BRED "    _______    _     " ANSI_RESET "   _   _____  ___ \n"),
+  _(ANSI_BRED " __/ __/ _ \\  (_)__ " ANSI_RESET "   | | / / _ \\/ _ \\\n"),
+  _(ANSI_BRED " _/ _// // / / / _ \\" ANSI_RESET "   | |/ / ___/ ___/\n"),
+  _(ANSI_BRED " /_/ /____(_)_/\\___/" ANSI_RESET "   |___/_/  /_/    \n"),
+  _("\n")
+};
+
+#undef _
+
+/** Pager line index */
+typedef struct
+{
+  /** Index into pager_vector */
+  u32 line;
+
+  /** Offset of the string in the line */
+  u32 offset;
+
+  /** Length of the string in the line */
+  u32 length;
+} unix_cli_pager_index_t;
+
+
+/** Unix CLI session. */
+typedef struct
+{
+  /** The file index held by unix.c */
+  u32 unix_file_index;
+
+  /** Vector of output pending write to file descriptor. */
+  u8 *output_vector;
+
+  /** Vector of input saved by Unix input node to be processed by
+     CLI process. */
+  u8 *input_vector;
+
+  /** This session has command history. */
+  u8 has_history;
+  /** Array of vectors of commands in the history. */
+  u8 **command_history;
+  /** The command currently pointed at by the history cursor. */
+  u8 *current_command;
+  /** How far from the end of the history array the user has browsed. */
+  i32 excursion;
+
+  /** Maximum number of history entries this session will store. */
+  u32 history_limit;
+
+  /** Current command line counter */
+  u32 command_number;
+
+  /** The string being searched for in the history. */
+  u8 *search_key;
+  /** If non-zero then the CLI is searching in the history array.
+   * - @c -1 means search backwards.
+   * - @c 1 means search forwards.
+   */
+  int search_mode;
+
+  /** Position of the insert cursor on the current input line */
+  u32 cursor;
+
+  /** Line mode or char mode */
+  u8 line_mode;
+
+  /** Set if the CRLF mode wants CR + LF */
+  u8 crlf_mode;
+
+  /** Can we do ANSI output? */
+  u8 ansi_capable;
+
+  /** Has the session started? */
+  u8 started;
+
+  /** Disable the pager? */
+  u8 no_pager;
+
+  /** Pager buffer */
+  u8 **pager_vector;
+
+  /** Index of line fragments in the pager buffer */
+  unix_cli_pager_index_t *pager_index;
+
+  /** Line number of top of page */
+  u32 pager_start;
+
+  /** Terminal width */
+  u32 width;
+
+  /** Terminal height */
+  u32 height;
+
+  /** Process node identifier */
+  u32 process_node_index;
+} unix_cli_file_t;
+
+/** Resets the pager buffer and other data.
+ * @param f The CLI session whose pager needs to be reset.
+ */
+always_inline void
+unix_cli_pager_reset (unix_cli_file_t * f)
+{
+  u8 **p;
+
+  f->pager_start = 0;
+
+  vec_free (f->pager_index);
+  f->pager_index = 0;
+
+  vec_foreach (p, f->pager_vector)
+  {
+    vec_free (*p);
+  }
+  vec_free (f->pager_vector);
+  f->pager_vector = 0;
+}
+
+/** Release storage used by a CLI session.
+ * @param f The CLI session whose storage needs to be released.
+ */
+always_inline void
+unix_cli_file_free (unix_cli_file_t * f)
+{
+  vec_free (f->output_vector);
+  vec_free (f->input_vector);
+  unix_cli_pager_reset (f);
+}
+
+/** CLI actions */
+typedef enum
+{
+  UNIX_CLI_PARSE_ACTION_NOACTION = 0,	/**< No action */
+  UNIX_CLI_PARSE_ACTION_CRLF,		/**< Carriage return, newline or enter */
+  UNIX_CLI_PARSE_ACTION_TAB,		/**< Tab key */
+  UNIX_CLI_PARSE_ACTION_ERASE,		/**< Erase cursor left */
+  UNIX_CLI_PARSE_ACTION_ERASERIGHT,	/**< Erase cursor right */
+  UNIX_CLI_PARSE_ACTION_UP,		/**< Up arrow */
+  UNIX_CLI_PARSE_ACTION_DOWN,		/**< Down arrow */
+  UNIX_CLI_PARSE_ACTION_LEFT,		/**< Left arrow */
+  UNIX_CLI_PARSE_ACTION_RIGHT,		/**< Right arrow */
+  UNIX_CLI_PARSE_ACTION_HOME,		/**< Home key (jump to start of line) */
+  UNIX_CLI_PARSE_ACTION_END,		/**< End key (jump to end of line) */
+  UNIX_CLI_PARSE_ACTION_WORDLEFT,	/**< Jump cursor to start of left word */
+  UNIX_CLI_PARSE_ACTION_WORDRIGHT,	/**< Jump cursor to start of right word */
+  UNIX_CLI_PARSE_ACTION_ERASELINELEFT,	/**< Erase line to left of cursor */
+  UNIX_CLI_PARSE_ACTION_ERASELINERIGHT,	/**< Erase line to right & including cursor */
+  UNIX_CLI_PARSE_ACTION_CLEAR,		/**< Clear the terminal */
+  UNIX_CLI_PARSE_ACTION_REVSEARCH,	/**< Search backwards in command history */
+  UNIX_CLI_PARSE_ACTION_FWDSEARCH,	/**< Search forwards in command history */
+  UNIX_CLI_PARSE_ACTION_YANK,		/**< Undo last erase action */
+  UNIX_CLI_PARSE_ACTION_TELNETIAC,	/**< Telnet control code */
+
+  UNIX_CLI_PARSE_ACTION_PAGER_CRLF,	/**< Enter pressed (CR, CRLF, LF, etc) */
+  UNIX_CLI_PARSE_ACTION_PAGER_QUIT,	/**< Exit the pager session */
+  UNIX_CLI_PARSE_ACTION_PAGER_NEXT,	/**< Scroll to next page */
+  UNIX_CLI_PARSE_ACTION_PAGER_DN,	/**< Scroll to next line */
+  UNIX_CLI_PARSE_ACTION_PAGER_UP,	/**< Scroll to previous line */
+  UNIX_CLI_PARSE_ACTION_PAGER_TOP,	/**< Scroll to first line */
+  UNIX_CLI_PARSE_ACTION_PAGER_BOTTOM,	/**< Scroll to last line */
+  UNIX_CLI_PARSE_ACTION_PAGER_PGDN,	/**< Scroll to next page */
+  UNIX_CLI_PARSE_ACTION_PAGER_PGUP,	/**< Scroll to previous page */
+  UNIX_CLI_PARSE_ACTION_PAGER_REDRAW,	/**< Clear and redraw the page on the terminal */
+  UNIX_CLI_PARSE_ACTION_PAGER_SEARCH,	/**< Search the pager buffer */
+
+  UNIX_CLI_PARSE_ACTION_PARTIALMATCH,	/**< Action parser found a partial match */
+  UNIX_CLI_PARSE_ACTION_NOMATCH		/**< Action parser did not find any match */
+} unix_cli_parse_action_t;
+
+/** @brief Mapping of input buffer strings to action values.
+ * @note This won't work as a hash since we need to be able to do
+ *       partial matches on the string.
+ */
+typedef struct
+{
+  u8 *input;			    /**< Input string to match. */
+  u32 len;			    /**< Length of input without final NUL. */
+  unix_cli_parse_action_t action;   /**< Action to take when matched. */
+} unix_cli_parse_actions_t;
+
+/** @brief Given a capital ASCII letter character return a @c NUL terminated
+ * string with the control code for that letter.
+ *
+ * @param c An ASCII character.
+ * @return A @c NUL terminated string of type @c u8[].
+ *
+ * @par Example
+ *     @c CTL('A') returns <code>{ 0x01, 0x00 }</code> as a @c u8[].
+ */
+#define CTL(c) (u8[]){ (c) - '@', 0 }
+
+#define _(a,b) { .input = (u8 *)(a), .len = sizeof(a) - 1, .action = (b) }
+/**
+ * Patterns to match on a CLI input stream.
+ * @showinitializer
+ */
+static unix_cli_parse_actions_t unix_cli_parse_strings[] = {
+  /* Line handling */
+  _("\r\n", UNIX_CLI_PARSE_ACTION_CRLF),	/* Must be before '\r' */
+  _("\n", UNIX_CLI_PARSE_ACTION_CRLF),
+  _("\r\0", UNIX_CLI_PARSE_ACTION_CRLF),	/* Telnet does this */
+  _("\r", UNIX_CLI_PARSE_ACTION_CRLF),
+
+  /* Unix shell control codes */
+  _(CTL ('B'), UNIX_CLI_PARSE_ACTION_LEFT),
+  _(CTL ('F'), UNIX_CLI_PARSE_ACTION_RIGHT),
+  _(CTL ('P'), UNIX_CLI_PARSE_ACTION_UP),
+  _(CTL ('N'), UNIX_CLI_PARSE_ACTION_DOWN),
+  _(CTL ('A'), UNIX_CLI_PARSE_ACTION_HOME),
+  _(CTL ('E'), UNIX_CLI_PARSE_ACTION_END),
+  _(CTL ('D'), UNIX_CLI_PARSE_ACTION_ERASERIGHT),
+  _(CTL ('U'), UNIX_CLI_PARSE_ACTION_ERASELINELEFT),
+  _(CTL ('K'), UNIX_CLI_PARSE_ACTION_ERASELINERIGHT),
+  _(CTL ('Y'), UNIX_CLI_PARSE_ACTION_YANK),
+  _(CTL ('L'), UNIX_CLI_PARSE_ACTION_CLEAR),
+  _(ESC "b", UNIX_CLI_PARSE_ACTION_WORDLEFT),	/* Alt-B */
+  _(ESC "f", UNIX_CLI_PARSE_ACTION_WORDRIGHT),	/* Alt-F */
+  _("\b", UNIX_CLI_PARSE_ACTION_ERASE),	/* ^H */
+  _("\x7f", UNIX_CLI_PARSE_ACTION_ERASE),	/* Backspace */
+  _("\t", UNIX_CLI_PARSE_ACTION_TAB),	/* ^I */
+
+  /* VT100 Normal mode - Broadest support */
+  _(CSI "A", UNIX_CLI_PARSE_ACTION_UP),
+  _(CSI "B", UNIX_CLI_PARSE_ACTION_DOWN),
+  _(CSI "C", UNIX_CLI_PARSE_ACTION_RIGHT),
+  _(CSI "D", UNIX_CLI_PARSE_ACTION_LEFT),
+  _(CSI "H", UNIX_CLI_PARSE_ACTION_HOME),
+  _(CSI "F", UNIX_CLI_PARSE_ACTION_END),
+  _(CSI "3~", UNIX_CLI_PARSE_ACTION_ERASERIGHT),	/* Delete */
+  _(CSI "1;5D", UNIX_CLI_PARSE_ACTION_WORDLEFT),	/* C-Left */
+  _(CSI "1;5C", UNIX_CLI_PARSE_ACTION_WORDRIGHT),	/* C-Right */
+
+  /* VT100 Application mode - Some Gnome Terminal functions use these */
+  _(ESC "OA", UNIX_CLI_PARSE_ACTION_UP),
+  _(ESC "OB", UNIX_CLI_PARSE_ACTION_DOWN),
+  _(ESC "OC", UNIX_CLI_PARSE_ACTION_RIGHT),
+  _(ESC "OD", UNIX_CLI_PARSE_ACTION_LEFT),
+  _(ESC "OH", UNIX_CLI_PARSE_ACTION_HOME),
+  _(ESC "OF", UNIX_CLI_PARSE_ACTION_END),
+
+  /* ANSI X3.41-1974 - sent by Microsoft Telnet and PuTTY */
+  _(CSI "1~", UNIX_CLI_PARSE_ACTION_HOME),
+  _(CSI "4~", UNIX_CLI_PARSE_ACTION_END),
+
+  /* Emacs-ish history search */
+  _(CTL ('S'), UNIX_CLI_PARSE_ACTION_FWDSEARCH),
+  _(CTL ('R'), UNIX_CLI_PARSE_ACTION_REVSEARCH),
+
+  /* Other protocol things */
+  _("\xff", UNIX_CLI_PARSE_ACTION_TELNETIAC),	/* IAC */
+  _("\0", UNIX_CLI_PARSE_ACTION_NOACTION),	/* NUL */
+  _(NULL, UNIX_CLI_PARSE_ACTION_NOMATCH)
+};
+
+/**
+ * Patterns to match when a CLI session is in the pager.
+ * @showinitializer
+ */
+static unix_cli_parse_actions_t unix_cli_parse_pager[] = {
+  /* Line handling */
+  _("\r\n", UNIX_CLI_PARSE_ACTION_PAGER_CRLF),	/* Must be before '\r' */
+  _("\n", UNIX_CLI_PARSE_ACTION_PAGER_CRLF),
+  _("\r\0", UNIX_CLI_PARSE_ACTION_PAGER_CRLF),	/* Telnet does this */
+  _("\r", UNIX_CLI_PARSE_ACTION_PAGER_CRLF),
+
+  /* Pager commands */
+  _(" ", UNIX_CLI_PARSE_ACTION_PAGER_NEXT),
+  _("q", UNIX_CLI_PARSE_ACTION_PAGER_QUIT),
+  _(CTL ('L'), UNIX_CLI_PARSE_ACTION_PAGER_REDRAW),
+  _(CTL ('R'), UNIX_CLI_PARSE_ACTION_PAGER_REDRAW),
+  _("/", UNIX_CLI_PARSE_ACTION_PAGER_SEARCH),
+
+  /* VT100 */
+  _(CSI "A", UNIX_CLI_PARSE_ACTION_PAGER_UP),
+  _(CSI "B", UNIX_CLI_PARSE_ACTION_PAGER_DN),
+  _(CSI "H", UNIX_CLI_PARSE_ACTION_PAGER_TOP),
+  _(CSI "F", UNIX_CLI_PARSE_ACTION_PAGER_BOTTOM),
+
+  /* VT100 Application mode */
+  _(ESC "OA", UNIX_CLI_PARSE_ACTION_PAGER_UP),
+  _(ESC "OB", UNIX_CLI_PARSE_ACTION_PAGER_DN),
+  _(ESC "OH", UNIX_CLI_PARSE_ACTION_PAGER_TOP),
+  _(ESC "OF", UNIX_CLI_PARSE_ACTION_PAGER_BOTTOM),
+
+  /* ANSI X3.41-1974 */
+  _(CSI "1~", UNIX_CLI_PARSE_ACTION_PAGER_TOP),
+  _(CSI "4~", UNIX_CLI_PARSE_ACTION_PAGER_BOTTOM),
+  _(CSI "5~", UNIX_CLI_PARSE_ACTION_PAGER_PGUP),
+  _(CSI "6~", UNIX_CLI_PARSE_ACTION_PAGER_PGDN),
+
+  /* Other protocol things */
+  _("\xff", UNIX_CLI_PARSE_ACTION_TELNETIAC),	/* IAC */
+  _("\0", UNIX_CLI_PARSE_ACTION_NOACTION),	/* NUL */
+  _(NULL, UNIX_CLI_PARSE_ACTION_NOMATCH)
+};
+
+#undef _
+
+/** CLI session events. */
+typedef enum
+{
+  UNIX_CLI_PROCESS_EVENT_READ_READY,  /**< A file descriptor has data to be read. */
+  UNIX_CLI_PROCESS_EVENT_QUIT,	      /**< A CLI session wants to close. */
+} unix_cli_process_event_type_t;
+
+/** CLI global state. */
+typedef struct
+{
+  /** Prompt string for CLI. */
+  u8 *cli_prompt;
+
+  /** Vec pool of CLI sessions. */
+  unix_cli_file_t *cli_file_pool;
+
+  /** Vec pool of unused session indices. */
+  u32 *unused_cli_process_node_indices;
+
+  /** The session index of the stdin cli */
+  u32 stdin_cli_file_index;
+
+  /** File pool index of current input. */
+  u32 current_input_file_index;
+} unix_cli_main_t;
+
+/** CLI global state */
+static unix_cli_main_t unix_cli_main;
+
+/**
+ * @brief Search for a byte sequence in the action list.
+ *
+ * Searches the @ref unix_cli_parse_actions_t list in @a a for a match with
+ * the bytes in @a input of maximum length @a ilen bytes.
+ * When a match is made @a *matched indicates how many bytes were matched.
+ * Returns a value from the enum @ref unix_cli_parse_action_t to indicate
+ * whether no match was found, a partial match was found or a complete
+ * match was found and what action, if any, should be taken.
+ *
+ * @param[in]  a        Actions list to search within.
+ * @param[in]  input    String fragment to search for.
+ * @param[in]  ilen     Length of the string in 'input'.
+ * @param[out] matched  Pointer to an integer that will contain the number
+ *                      of bytes matched when a complete match is found.
+ *
+ * @return Action from @ref unix_cli_parse_action_t that the string fragment
+ *         matches.
+ *         @ref UNIX_CLI_PARSE_ACTION_PARTIALMATCH is returned when the
+ *         whole input string matches the start of at least one action.
+ *         @ref UNIX_CLI_PARSE_ACTION_NOMATCH is returned when there is no
+ *         match at all.
+ */
+static unix_cli_parse_action_t
+unix_cli_match_action (unix_cli_parse_actions_t * a,
+		       u8 * input, u32 ilen, i32 * matched)
+{
+  u8 partial = 0;
+
+  while (a->input)
+    {
+      if (ilen >= a->len)
+	{
+	  /* see if the start of the input buffer exactly matches the current
+	   * action string. */
+	  if (memcmp (input, a->input, a->len) == 0)
+	    {
+	      *matched = a->len;
+	      return a->action;
+	    }
+	}
+      else
+	{
+	  /* if the first ilen characters match, flag this as a partial -
+	   * meaning keep collecting bytes in case of a future match */
+	  if (memcmp (input, a->input, ilen) == 0)
+	    partial = 1;
+	}
+
+      /* check next action */
+      a++;
+    }
+
+  return partial ?
+    UNIX_CLI_PARSE_ACTION_PARTIALMATCH : UNIX_CLI_PARSE_ACTION_NOMATCH;
+}
+
+
+/** Add bytes to the output vector and then flagg the I/O system that bytes
+ * are available to be sent.
+ */
+static void
+unix_cli_add_pending_output (unix_file_t * uf,
+			     unix_cli_file_t * cf,
+			     u8 * buffer, uword buffer_bytes)
+{
+  unix_main_t *um = &unix_main;
+
+  vec_add (cf->output_vector, buffer, buffer_bytes);
+  if (vec_len (cf->output_vector) > 0)
+    {
+      int skip_update = 0 != (uf->flags & UNIX_FILE_DATA_AVAILABLE_TO_WRITE);
+      uf->flags |= UNIX_FILE_DATA_AVAILABLE_TO_WRITE;
+      if (!skip_update)
+	um->file_update (uf, UNIX_FILE_UPDATE_MODIFY);
+    }
+}
+
+/** Delete all bytes from the output vector and flag the I/O system
+ * that no more bytes are available to be sent.
+ */
+static void
+unix_cli_del_pending_output (unix_file_t * uf,
+			     unix_cli_file_t * cf, uword n_bytes)
+{
+  unix_main_t *um = &unix_main;
+
+  vec_delete (cf->output_vector, n_bytes, 0);
+  if (vec_len (cf->output_vector) <= 0)
+    {
+      int skip_update = 0 == (uf->flags & UNIX_FILE_DATA_AVAILABLE_TO_WRITE);
+      uf->flags &= ~UNIX_FILE_DATA_AVAILABLE_TO_WRITE;
+      if (!skip_update)
+	um->file_update (uf, UNIX_FILE_UPDATE_MODIFY);
+    }
+}
+
+/** @brief A bit like strchr with a buffer length limit.
+ * Search a buffer for the first instance of a character up to the limit of
+ * the buffer length. If found then return the position of that character.
+ *
+ * The key departure from strchr is that if the character is not found then
+ * return the buffer length.
+ *
+ * @param chr The byte value to search for.
+ * @param str The buffer in which to search for the value.
+ * @param len The depth into the buffer to search.
+ *
+ * @return The index of the first occurence of \c chr. If \c chr is not
+ *          found then \c len instead.
+ */
+always_inline word
+unix_vlib_findchr (u8 chr, u8 * str, word len)
+{
+  word i = 0;
+  for (i = 0; i < len; i++, str++)
+    {
+      if (*str == chr)
+	return i;
+    }
+  return len;
+}
+
+/** @brief Send a buffer to the CLI stream if possible, enqueue it otherwise.
+ * Attempts to write given buffer to the file descriptor of the given
+ * Unix CLI session. If that session already has data in the output buffer
+ * or if the write attempt tells us to try again later then the given buffer
+ * is appended to the pending output buffer instead.
+ *
+ * This is typically called only from \c unix_vlib_cli_output_cooked since
+ * that is where CRLF handling occurs or from places where we explicitly do
+ * not want cooked handling.
+ *
+ * @param cf Unix CLI session of the desired stream to write to.
+ * @param uf The Unix file structure of the desired stream to write to.
+ * @param buffer Pointer to the buffer that needs to be written.
+ * @param buffer_bytes The number of bytes from \c buffer to write.
+ */
+static void
+unix_vlib_cli_output_raw (unix_cli_file_t * cf,
+			  unix_file_t * uf, u8 * buffer, uword buffer_bytes)
+{
+  int n = 0;
+
+  if (vec_len (cf->output_vector) == 0)
+    n = write (uf->file_descriptor, buffer, buffer_bytes);
+
+  if (n < 0 && errno != EAGAIN)
+    {
+      clib_unix_warning ("write");
+    }
+  else if ((word) n < (word) buffer_bytes)
+    {
+      /* We got EAGAIN or we already have stuff in the buffer;
+       * queue up whatever didn't get sent for later. */
+      if (n < 0)
+	n = 0;
+      unix_cli_add_pending_output (uf, cf, buffer + n, buffer_bytes - n);
+    }
+}
+
+/** @brief Process a buffer for CRLF handling before outputting it to the CLI.
+ *
+ * @param cf Unix CLI session of the desired stream to write to.
+ * @param uf The Unix file structure of the desired stream to write to.
+ * @param buffer Pointer to the buffer that needs to be written.
+ * @param buffer_bytes The number of bytes from \c buffer to write.
+ */
+static void
+unix_vlib_cli_output_cooked (unix_cli_file_t * cf,
+			     unix_file_t * uf,
+			     u8 * buffer, uword buffer_bytes)
+{
+  word end = 0, start = 0;
+
+  while (end < buffer_bytes)
+    {
+      if (cf->crlf_mode)
+	{
+	  /* iterate the line on \n's so we can insert a \r before it */
+	  end = unix_vlib_findchr ('\n',
+				   buffer + start,
+				   buffer_bytes - start) + start;
+	}
+      else
+	{
+	  /* otherwise just send the whole buffer */
+	  end = buffer_bytes;
+	}
+
+      unix_vlib_cli_output_raw (cf, uf, buffer + start, end - start);
+
+      if (cf->crlf_mode)
+	{
+	  if (end < buffer_bytes)
+	    {
+	      unix_vlib_cli_output_raw (cf, uf, (u8 *) "\r\n", 2);
+	      end++;		/* skip the \n that we already sent */
+	    }
+	  start = end;
+	}
+    }
+}
+
+/** @brief Output the CLI prompt */
+static void
+unix_cli_cli_prompt (unix_cli_file_t * cf, unix_file_t * uf)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+
+  unix_vlib_cli_output_raw (cf, uf, cm->cli_prompt, vec_len (cm->cli_prompt));
+}
+
+/** @brief Output a pager prompt and show number of buffered lines */
+static void
+unix_cli_pager_prompt (unix_cli_file_t * cf, unix_file_t * uf)
+{
+  u8 *prompt;
+  u32 h;
+
+  h = cf->pager_start + (cf->height - 1);
+  if (h > vec_len (cf->pager_index))
+    h = vec_len (cf->pager_index);
+
+  prompt = format (0, "\r%s-- more -- (%d-%d/%d)%s",
+		   cf->ansi_capable ? ANSI_BOLD : "",
+		   cf->pager_start + 1,
+		   h,
+		   vec_len (cf->pager_index),
+		   cf->ansi_capable ? ANSI_RESET : "");
+
+  unix_vlib_cli_output_cooked (cf, uf, prompt, vec_len (prompt));
+
+  vec_free (prompt);
+}
+
+/** @brief Output a pager "skipping" message */
+static void
+unix_cli_pager_message (unix_cli_file_t * cf, unix_file_t * uf,
+			char *message, char *postfix)
+{
+  u8 *prompt;
+
+  prompt = format (0, "\r%s-- %s --%s%s",
+		   cf->ansi_capable ? ANSI_BOLD : "",
+		   message, cf->ansi_capable ? ANSI_RESET : "", postfix);
+
+  unix_vlib_cli_output_cooked (cf, uf, prompt, vec_len (prompt));
+
+  vec_free (prompt);
+}
+
+/** @brief Erase the printed pager prompt */
+static void
+unix_cli_pager_prompt_erase (unix_cli_file_t * cf, unix_file_t * uf)
+{
+  if (cf->ansi_capable)
+    {
+      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\r", 1);
+      unix_vlib_cli_output_cooked (cf, uf,
+				   (u8 *) ANSI_CLEARLINE,
+				   sizeof (ANSI_CLEARLINE) - 1);
+    }
+  else
+    {
+      int i;
+
+      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\r", 1);
+      for (i = 0; i < cf->width - 1; i++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) " ", 1);
+      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\r", 1);
+    }
+}
+
+/** @brief Uses an ANSI escape sequence to move the cursor */
+static void
+unix_cli_ansi_cursor (unix_cli_file_t * cf, unix_file_t * uf, u16 x, u16 y)
+{
+  u8 *str;
+
+  str = format (0, "%s%d;%dH", CSI, y, x);
+
+  unix_vlib_cli_output_cooked (cf, uf, str, vec_len (str));
+
+  vec_free (str);
+}
+
+/** Redraw the currently displayed page of text.
+ * @param cf CLI session to redraw the pager buffer of.
+ * @param uf Unix file of the CLI session.
+ */
+static void
+unix_cli_pager_redraw (unix_cli_file_t * cf, unix_file_t * uf)
+{
+  unix_cli_pager_index_t *pi = NULL;
+  u8 *line = NULL;
+  word i;
+
+  /* No active pager? Do nothing. */
+  if (!vec_len (cf->pager_index))
+    return;
+
+  if (cf->ansi_capable)
+    {
+      /* If we have ANSI, send the clear screen sequence */
+      unix_vlib_cli_output_cooked (cf, uf,
+				   (u8 *) ANSI_CLEAR,
+				   sizeof (ANSI_CLEAR) - 1);
+    }
+  else
+    {
+      /* Otherwise make sure we're on a blank line */
+      unix_cli_pager_prompt_erase (cf, uf);
+    }
+
+  /* (Re-)send the current page of content */
+  for (i = 0; i < cf->height - 1 &&
+       i + cf->pager_start < vec_len (cf->pager_index); i++)
+    {
+      pi = &cf->pager_index[cf->pager_start + i];
+      line = cf->pager_vector[pi->line] + pi->offset;
+
+      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+    }
+  /* if the last line didn't end in newline, add a newline */
+  if (pi && line[pi->length - 1] != '\n')
+    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+
+  unix_cli_pager_prompt (cf, uf);
+}
+
+/** @brief Process and add a line to the pager index.
+ * In normal operation this function will take the given character string
+ * found in @c line and with length @c len_or_index and iterates the over the
+ * contents, adding each line of text discovered within it to the
+ * pager index. Lines are identified by newlines ("<code>\\n</code>") and by
+ * strings longer than the width of the terminal.
+ *
+ * If instead @c line is @c NULL then @c len_or_index is taken to mean the
+ * index of an existing line in the pager buffer; this simply means that the
+ * input line does not need to be cloned since we alreayd have it. This is
+ * typical if we are reindexing the pager buffer.
+ *
+ * @param cf           The CLI session whose pager we are adding to.
+ * @param line         The string of text to be indexed into the pager buffer.
+ *                     If @c line is @c NULL then the mode of operation
+ *                     changes slightly; see the description above.
+ * @param len_or_index If @c line is a pointer to a string then this parameter
+ *                     indicates the length of that string; Otherwise this
+ *                     value provides the index in the pager buffer of an
+ *                     existing string to be indexed.
+ */
+static void
+unix_cli_pager_add_line (unix_cli_file_t * cf, u8 * line, word len_or_index)
+{
+  u8 *p;
+  word i, j, k;
+  word line_index, len;
+  u32 width = cf->width;
+  unix_cli_pager_index_t *pi;
+
+  if (line == NULL)
+    {
+      /* Use a line already in the pager buffer */
+      line_index = len_or_index;
+      p = cf->pager_vector[line_index];
+      len = vec_len (p);
+    }
+  else
+    {
+      len = len_or_index;
+      /* Add a copy of the raw string to the pager buffer */
+      p = vec_new (u8, len);
+      clib_memcpy (p, line, len);
+
+      /* store in pager buffer */
+      line_index = vec_len (cf->pager_vector);
+      vec_add1 (cf->pager_vector, p);
+    }
+
+  i = 0;
+  while (i < len)
+    {
+      /* Find the next line, or run to terminal width, or run to EOL */
+      int l = len - i;
+      j = unix_vlib_findchr ((u8) '\n', p, l < width ? l : width);
+
+      if (j < l && p[j] == '\n')	/* incl \n */
+	j++;
+
+      /* Add the line to the index */
+      k = vec_len (cf->pager_index);
+      vec_validate (cf->pager_index, k);
+      pi = &cf->pager_index[k];
+
+      pi->line = line_index;
+      pi->offset = i;
+      pi->length = j;
+
+      i += j;
+      p += j;
+    }
+}
+
+/** @brief Reindex entire pager buffer.
+ * Resets the current pager index and then re-adds the lines in the pager
+ * buffer to the index.
+ *
+ * Additionally this function attempts to retain the current page start
+ * line offset by searching for the same top-of-screen line in the new index.
+ *
+ * @param cf The CLI session whose pager buffer should be reindexed.
+ */
+static void
+unix_cli_pager_reindex (unix_cli_file_t * cf)
+{
+  word i, old_line, old_offset;
+  unix_cli_pager_index_t *pi;
+
+  /* If there is nothing in the pager buffer then make sure the index
+   * is empty and move on.
+   */
+  if (cf->pager_vector == 0)
+    {
+      vec_reset_length (cf->pager_index);
+      return;
+    }
+
+  /* Retain a pointer to the current page start line so we can
+   * find it later
+   */
+  pi = &cf->pager_index[cf->pager_start];
+  old_line = pi->line;
+  old_offset = pi->offset;
+
+  /* Re-add the buffered lines to the index */
+  vec_reset_length (cf->pager_index);
+  vec_foreach_index (i, cf->pager_vector)
+  {
+    unix_cli_pager_add_line (cf, NULL, i);
+  }
+
+  /* Attempt to re-locate the previously stored page start line */
+  vec_foreach_index (i, cf->pager_index)
+  {
+    pi = &cf->pager_index[i];
+
+    if (pi->line == old_line &&
+	(pi->offset <= old_offset || pi->offset + pi->length > old_offset))
+      {
+	/* Found it! */
+	cf->pager_start = i;
+	break;
+      }
+  }
+
+  /* In case the start line was not found (rare), ensure the pager start
+   * index is within bounds
+   */
+  if (cf->pager_start >= vec_len (cf->pager_index))
+    {
+      if (!cf->height || vec_len (cf->pager_index) < (cf->height - 1))
+	cf->pager_start = 0;
+      else
+	cf->pager_start = vec_len (cf->pager_index) - (cf->height - 1);
+    }
+}
+
+/** VLIB CLI output function.
+ *
+ * If the terminal has a pager configured then this function takes care
+ * of collating output into the pager buffer; ensuring only the first page
+ * is displayed and any lines in excess of the first page are buffered.
+ *
+ * If the maximum number of index lines in the buffer is exceeded then the
+ * pager is cancelled and the contents of the current buffer are sent to the
+ * terminal.
+ *
+ * If there is no pager configured then the output is sent directly to the
+ * terminal.
+ *
+ * @param cli_file_index Index of the CLI session where this output is
+ *                       directed.
+ * @param buffer         String of printabe bytes to be output.
+ * @param buffer_bytes   The number of bytes in @c buffer to be output.
+ */
+static void
+unix_vlib_cli_output (uword cli_file_index, u8 * buffer, uword buffer_bytes)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  unix_file_t *uf;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cli_file_index);
+  uf = pool_elt_at_index (um->file_pool, cf->unix_file_index);
+
+  if (cf->no_pager || um->cli_pager_buffer_limit == 0 || cf->height == 0)
+    {
+      unix_vlib_cli_output_cooked (cf, uf, buffer, buffer_bytes);
+    }
+  else
+    {
+      word row = vec_len (cf->pager_index);
+      u8 *line;
+      unix_cli_pager_index_t *pi;
+
+      /* Index and add the output lines to the pager buffer. */
+      unix_cli_pager_add_line (cf, buffer, buffer_bytes);
+
+      /* Now iterate what was added to display the lines.
+       * If we reach the bottom of the page, display a prompt.
+       */
+      while (row < vec_len (cf->pager_index))
+	{
+	  if (row < cf->height - 1)
+	    {
+	      /* output this line */
+	      pi = &cf->pager_index[row];
+	      line = cf->pager_vector[pi->line] + pi->offset;
+	      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+
+	      /* if the last line didn't end in newline, and we're at the
+	       * bottom of the page, add a newline */
+	      if (line[pi->length - 1] != '\n' && row == cf->height - 2)
+		unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+	    }
+	  else
+	    {
+	      /* Display the pager prompt every 10 lines */
+	      if (!(row % 10))
+		unix_cli_pager_prompt (cf, uf);
+	    }
+	  row++;
+	}
+
+      /* Check if we went over the pager buffer limit */
+      if (vec_len (cf->pager_index) > um->cli_pager_buffer_limit)
+	{
+	  /* Stop using the pager for the remainder of this CLI command */
+	  cf->no_pager = 2;
+
+	  /* If we likely printed the prompt, erase it */
+	  if (vec_len (cf->pager_index) > cf->height - 1)
+	    unix_cli_pager_prompt_erase (cf, uf);
+
+	  /* Dump out the contents of the buffer */
+	  for (row = cf->pager_start + (cf->height - 1);
+	       row < vec_len (cf->pager_index); row++)
+	    {
+	      pi = &cf->pager_index[row];
+	      line = cf->pager_vector[pi->line] + pi->offset;
+	      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+	    }
+
+	  unix_cli_pager_reset (cf);
+	}
+    }
+}
+
+/** Identify whether a terminal type is ANSI capable.
+ *
+ * Compares the string given in @c term with a list of terminal types known
+ * to support ANSI escape sequences.
+ *
+ * This list contains, for example, @c xterm, @c screen and @c ansi.
+ *
+ * @param term A string with a terminal type in it.
+ * @param len The length of the string in @c term.
+ *
+ * @return @c 1 if the terminal type is recognized as supporting ANSI
+ *         terminal sequences; @c 0 otherwise.
+ */
+static u8
+unix_cli_terminal_type (u8 * term, uword len)
+{
+  /* This may later be better done as a hash of some sort. */
+#define _(a) do { \
+    if (strncasecmp(a, (char *)term, (size_t)len) == 0) return 1; \
+  } while(0)
+
+  _("xterm");
+  _("xterm-color");
+  _("xterm-256color");		/* iTerm on Mac */
+  _("screen");
+  _("ansi");			/* Microsoft Telnet */
+#undef _
+
+  return 0;
+}
+
+/** @brief Emit initial welcome banner and prompt on a connection. */
+static void
+unix_cli_file_welcome (unix_cli_main_t * cm, unix_cli_file_t * cf)
+{
+  unix_main_t *um = &unix_main;
+  unix_file_t *uf = pool_elt_at_index (um->file_pool, cf->unix_file_index);
+  unix_cli_banner_t *banner;
+  int i, len;
+
+  /*
+   * Put the first bytes directly into the buffer so that further output is
+   * queued until everything is ready. (oterwise initial prompt can appear
+   * mid way through VPP initialization)
+   */
+  unix_cli_add_pending_output (uf, cf, (u8 *) "\r", 1);
+
+  if (!um->cli_no_banner)
+    {
+      if (cf->ansi_capable)
+	{
+	  banner = unix_cli_banner_color;
+	  len = ARRAY_LEN (unix_cli_banner_color);
+	}
+      else
+	{
+	  banner = unix_cli_banner;
+	  len = ARRAY_LEN (unix_cli_banner);
+	}
+
+      for (i = 0; i < len; i++)
+	{
+	  unix_vlib_cli_output_cooked (cf, uf,
+				       banner[i].line, banner[i].length);
+	}
+    }
+
+  /* Prompt. */
+  unix_cli_cli_prompt (cf, uf);
+
+  cf->started = 1;
+}
+
+/** @brief A failsafe triggered on a timer to ensure we send the prompt
+ * to telnet sessions that fail to negotiate the terminal type. */
+static void
+unix_cli_file_welcome_timer (any arg, f64 delay)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  (void) delay;
+
+  /* Check the connection didn't close already */
+  if (pool_is_free_index (cm->cli_file_pool, (uword) arg))
+    return;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, (uword) arg);
+
+  if (!cf->started)
+    unix_cli_file_welcome (cm, cf);
+}
+
+/** @brief A mostly no-op Telnet state machine.
+ * Process Telnet command bytes in a way that ensures we're mostly
+ * transparent to the Telnet protocol. That is, it's mostly a no-op.
+ *
+ * @return -1 if we need more bytes, otherwise a positive integer number of
+ *          bytes to consume from the input_vector, not including the initial
+ *          IAC byte.
+ */
+static i32
+unix_cli_process_telnet (unix_main_t * um,
+			 unix_cli_file_t * cf,
+			 unix_file_t * uf, u8 * input_vector, uword len)
+{
+  /* Input_vector starts at IAC byte.
+   * See if we have a complete message; if not, return -1 so we wait for more.
+   * if we have a complete message, consume those bytes from the vector.
+   */
+  i32 consume = 0;
+
+  if (len == 1)
+    return -1;			/* want more bytes */
+
+  switch (input_vector[1])
+    {
+    case IAC:
+      /* two IAC's in a row means to pass through 0xff.
+       * since that makes no sense here, just consume it.
+       */
+      consume = 1;
+      break;
+
+    case WILL:
+    case WONT:
+    case DO:
+    case DONT:
+      /* Expect 3 bytes */
+      if (vec_len (input_vector) < 3)
+	return -1;		/* want more bytes */
+
+      consume = 2;
+      break;
+
+    case SB:
+      {
+	/* Sub option - search ahead for IAC SE to end it */
+	i32 i;
+	for (i = 3; i < len && i < UNIX_CLI_MAX_DEPTH_TELNET; i++)
+	  {
+	    if (input_vector[i - 1] == IAC && input_vector[i] == SE)
+	      {
+		/* We have a complete message; see if we care about it */
+		switch (input_vector[2])
+		  {
+		  case TELOPT_TTYPE:
+		    if (input_vector[3] != 0)
+		      break;
+		    /* See if the terminal type is ANSI capable */
+		    cf->ansi_capable =
+		      unix_cli_terminal_type (input_vector + 4, i - 5);
+		    /* If session not started, we can release the pause */
+		    if (!cf->started)
+		      /* Send the welcome banner and initial prompt */
+		      unix_cli_file_welcome (&unix_cli_main, cf);
+		    break;
+
+		  case TELOPT_NAWS:
+		    /* Window size */
+		    if (i != 8)	/* check message is correct size */
+		      break;
+		    cf->width =
+		      clib_net_to_host_u16 (*((u16 *) (input_vector + 3)));
+		    cf->height =
+		      clib_net_to_host_u16 (*((u16 *) (input_vector + 5)));
+		    /* reindex pager buffer */
+		    unix_cli_pager_reindex (cf);
+		    /* redraw page */
+		    unix_cli_pager_redraw (cf, uf);
+		    break;
+
+		  default:
+		    break;
+		  }
+		/* Consume it all */
+		consume = i;
+		break;
+	      }
+	  }
+
+	if (i == UNIX_CLI_MAX_DEPTH_TELNET)
+	  consume = 1;		/* hit max search depth, advance one byte */
+
+	if (consume == 0)
+	  return -1;		/* want more bytes */
+
+	break;
+      }
+
+    case GA:
+    case EL:
+    case EC:
+    case AO:
+    case IP:
+    case BREAK:
+    case DM:
+    case NOP:
+    case SE:
+    case EOR:
+    case ABORT:
+    case SUSP:
+    case xEOF:
+      /* Simple one-byte messages */
+      consume = 1;
+      break;
+
+    case AYT:
+      /* Are You There - trigger a visible response */
+      consume = 1;
+      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "fd.io VPP\n", 10);
+      break;
+
+    default:
+      /* Unknown command! Eat the IAC byte */
+      break;
+    }
+
+  return consume;
+}
+
+/** @brief Process actionable input.
+ * Based on the \c action process the input; this typically involves
+ * searching the command history or editing the current command line.
+ */
+static int
+unix_cli_line_process_one (unix_cli_main_t * cm,
+			   unix_main_t * um,
+			   unix_cli_file_t * cf,
+			   unix_file_t * uf,
+			   u8 input, unix_cli_parse_action_t action)
+{
+  u8 *prev;
+  int j, delta;
+
+  switch (action)
+    {
+    case UNIX_CLI_PARSE_ACTION_NOACTION:
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_REVSEARCH:
+    case UNIX_CLI_PARSE_ACTION_FWDSEARCH:
+      if (!cf->has_history || !cf->history_limit)
+	break;
+      if (cf->search_mode == 0)
+	{
+	  /* Erase the current command (if any) */
+	  for (j = 0; j < (vec_len (cf->current_command)); j++)
+	    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b \b", 3);
+
+	  vec_reset_length (cf->search_key);
+	  vec_reset_length (cf->current_command);
+	  if (action == UNIX_CLI_PARSE_ACTION_REVSEARCH)
+	    cf->search_mode = -1;
+	  else
+	    cf->search_mode = 1;
+	  cf->cursor = 0;
+	}
+      else
+	{
+	  if (action == UNIX_CLI_PARSE_ACTION_REVSEARCH)
+	    cf->search_mode = -1;
+	  else
+	    cf->search_mode = 1;
+
+	  cf->excursion += cf->search_mode;
+	  goto search_again;
+	}
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_ERASELINELEFT:
+      /* Erase the command from the cursor to the start */
+
+      /* Shimmy forwards to the new end of line position */
+      delta = vec_len (cf->current_command) - cf->cursor;
+      for (j = cf->cursor; j > delta; j--)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+      /* Zap from here to the end of what is currently displayed */
+      for (; j < (vec_len (cf->current_command)); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) " ", 1);
+      /* Get back to the start of the line */
+      for (j = 0; j < (vec_len (cf->current_command)); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+
+      j = vec_len (cf->current_command) - cf->cursor;
+      memmove (cf->current_command, cf->current_command + cf->cursor, j);
+      _vec_len (cf->current_command) = j;
+
+      /* Print the new contents */
+      unix_vlib_cli_output_cooked (cf, uf, cf->current_command, j);
+      /* Shimmy back to the start */
+      for (j = 0; j < (vec_len (cf->current_command)); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+      cf->cursor = 0;
+
+      cf->search_mode = 0;
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_ERASELINERIGHT:
+      /* Erase the command from the cursor to the end */
+
+      /* Zap from cursor to end of what is currently displayed */
+      for (j = cf->cursor; j < (vec_len (cf->current_command)); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) " ", 1);
+      /* Get back to where we were */
+      for (j = cf->cursor; j < (vec_len (cf->current_command)); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+
+      /* Truncate the line at the cursor */
+      _vec_len (cf->current_command) = cf->cursor;
+
+      cf->search_mode = 0;
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_LEFT:
+      if (cf->cursor > 0)
+	{
+	  unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+	  cf->cursor--;
+	}
+
+      cf->search_mode = 0;
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_RIGHT:
+      if (cf->cursor < vec_len (cf->current_command))
+	{
+	  /* have to emit the character under the cursor */
+	  unix_vlib_cli_output_cooked (cf, uf,
+				       cf->current_command + cf->cursor, 1);
+	  cf->cursor++;
+	}
+
+      cf->search_mode = 0;
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_UP:
+    case UNIX_CLI_PARSE_ACTION_DOWN:
+      if (!cf->has_history || !cf->history_limit)
+	break;
+      cf->search_mode = 0;
+      /* Erase the command */
+      for (j = cf->cursor; j < (vec_len (cf->current_command)); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) " ", 1);
+      for (j = 0; j < (vec_len (cf->current_command)); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b \b", 3);
+      vec_reset_length (cf->current_command);
+      if (vec_len (cf->command_history))
+	{
+	  if (action == UNIX_CLI_PARSE_ACTION_UP)
+	    delta = -1;
+	  else
+	    delta = 1;
+
+	  cf->excursion += delta;
+
+	  if (cf->excursion == vec_len (cf->command_history))
+	    {
+	      /* down-arrowed to last entry - want a blank line */
+	      _vec_len (cf->current_command) = 0;
+	    }
+	  else if (cf->excursion < 0)
+	    {
+	      /* up-arrowed over the start to the end, want a blank line */
+	      cf->excursion = vec_len (cf->command_history);
+	      _vec_len (cf->current_command) = 0;
+	    }
+	  else
+	    {
+	      if (cf->excursion > (i32) vec_len (cf->command_history) - 1)
+		/* down-arrowed past end - wrap to start */
+		cf->excursion = 0;
+
+	      /* Print the command at the current position */
+	      prev = cf->command_history[cf->excursion];
+	      vec_validate (cf->current_command, vec_len (prev) - 1);
+
+	      clib_memcpy (cf->current_command, prev, vec_len (prev));
+	      _vec_len (cf->current_command) = vec_len (prev);
+	      unix_vlib_cli_output_cooked (cf, uf, cf->current_command,
+					   vec_len (cf->current_command));
+	    }
+	  cf->cursor = vec_len (cf->current_command);
+
+	  break;
+	}
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_HOME:
+      if (vec_len (cf->current_command) && cf->cursor > 0)
+	{
+	  while (cf->cursor)
+	    {
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+	      cf->cursor--;
+	    }
+	}
+
+      cf->search_mode = 0;
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_END:
+      if (vec_len (cf->current_command) &&
+	  cf->cursor < vec_len (cf->current_command))
+	{
+	  unix_vlib_cli_output_cooked (cf, uf,
+				       cf->current_command + cf->cursor,
+				       vec_len (cf->current_command) -
+				       cf->cursor);
+	  cf->cursor = vec_len (cf->current_command);
+	}
+
+      cf->search_mode = 0;
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_WORDLEFT:
+      if (vec_len (cf->current_command) && cf->cursor > 0)
+	{
+	  j = cf->cursor;
+
+	  unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+	  j--;
+
+	  while (j && isspace (cf->current_command[j]))
+	    {
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+	      j--;
+	    }
+	  while (j && !isspace (cf->current_command[j]))
+	    {
+	      if (isspace (cf->current_command[j - 1]))
+		break;
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+	      j--;
+	    }
+
+	  cf->cursor = j;
+	}
+
+      cf->search_mode = 0;
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_WORDRIGHT:
+      if (vec_len (cf->current_command) &&
+	  cf->cursor < vec_len (cf->current_command))
+	{
+	  int e = vec_len (cf->current_command);
+	  j = cf->cursor;
+	  while (j < e && !isspace (cf->current_command[j]))
+	    j++;
+	  while (j < e && isspace (cf->current_command[j]))
+	    j++;
+	  unix_vlib_cli_output_cooked (cf, uf,
+				       cf->current_command + cf->cursor,
+				       j - cf->cursor);
+	  cf->cursor = j;
+	}
+
+      cf->search_mode = 0;
+      break;
+
+
+    case UNIX_CLI_PARSE_ACTION_ERASE:
+      if (vec_len (cf->current_command))
+	{
+	  if (cf->cursor == vec_len (cf->current_command))
+	    {
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b \b", 3);
+	      _vec_len (cf->current_command)--;
+	      cf->cursor--;
+	    }
+	  else if (cf->cursor > 0)
+	    {
+	      /* shift everything at & to the right of the cursor left by 1 */
+	      j = vec_len (cf->current_command) - cf->cursor;
+	      memmove (cf->current_command + cf->cursor - 1,
+		       cf->current_command + cf->cursor, j);
+	      _vec_len (cf->current_command)--;
+	      cf->cursor--;
+	      /* redraw the rest of the line */
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+	      unix_vlib_cli_output_cooked (cf, uf,
+					   cf->current_command + cf->cursor,
+					   j);
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) " \b\b", 3);
+	      /* and shift the terminal cursor back where it should be */
+	      while (--j)
+		unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+	    }
+	}
+      cf->search_mode = 0;
+      cf->excursion = 0;
+      vec_reset_length (cf->search_key);
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_ERASERIGHT:
+      if (vec_len (cf->current_command))
+	{
+	  if (cf->cursor < vec_len (cf->current_command))
+	    {
+	      /* shift everything to the right of the cursor left by 1 */
+	      j = vec_len (cf->current_command) - cf->cursor - 1;
+	      memmove (cf->current_command + cf->cursor,
+		       cf->current_command + cf->cursor + 1, j);
+	      _vec_len (cf->current_command)--;
+	      /* redraw the rest of the line */
+	      unix_vlib_cli_output_cooked (cf, uf,
+					   cf->current_command + cf->cursor,
+					   j);
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) " \b", 2);
+	      /* and shift the terminal cursor back where it should be */
+	      if (j)
+		{
+		  unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+		  while (--j)
+		    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+		}
+	    }
+	}
+      else if (input == 'D' - '@')
+	{
+	  /* ^D with no command entered = quit */
+	  unix_vlib_cli_output_cooked (cf, uf, (u8 *) "quit\n", 5);
+	  vlib_process_signal_event (um->vlib_main,
+				     vlib_current_process (um->vlib_main),
+				     UNIX_CLI_PROCESS_EVENT_QUIT,
+				     cf - cm->cli_file_pool);
+	}
+      cf->search_mode = 0;
+      cf->excursion = 0;
+      vec_reset_length (cf->search_key);
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_CLEAR:
+      /* If we're in ANSI mode, clear the screen.
+       * Then redraw the prompt and any existing command input, then put
+       * the cursor back where it was in that line.
+       */
+      if (cf->ansi_capable)
+	unix_vlib_cli_output_cooked (cf, uf,
+				     (u8 *) ANSI_CLEAR,
+				     sizeof (ANSI_CLEAR) - 1);
+      else
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+
+      unix_vlib_cli_output_raw (cf, uf,
+				cm->cli_prompt, vec_len (cm->cli_prompt));
+      unix_vlib_cli_output_raw (cf, uf,
+				cf->current_command,
+				vec_len (cf->current_command));
+      for (j = cf->cursor; j < vec_len (cf->current_command); j++)
+	unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b", 1);
+
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_TAB:
+    case UNIX_CLI_PARSE_ACTION_YANK:
+      /* TODO */
+      break;
+
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_QUIT:
+    pager_quit:
+      unix_cli_pager_prompt_erase (cf, uf);
+      unix_cli_pager_reset (cf);
+      unix_cli_cli_prompt (cf, uf);
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_NEXT:
+    case UNIX_CLI_PARSE_ACTION_PAGER_PGDN:
+      /* show next page of the buffer */
+      if (cf->height + cf->pager_start < vec_len (cf->pager_index))
+	{
+	  u8 *line = NULL;
+	  unix_cli_pager_index_t *pi = NULL;
+
+	  int m = cf->pager_start + (cf->height - 1);
+	  unix_cli_pager_prompt_erase (cf, uf);
+	  for (j = m;
+	       j < vec_len (cf->pager_index) && cf->pager_start < m;
+	       j++, cf->pager_start++)
+	    {
+	      pi = &cf->pager_index[j];
+	      line = cf->pager_vector[pi->line] + pi->offset;
+	      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+	    }
+	  /* if the last line didn't end in newline, add a newline */
+	  if (pi && line[pi->length - 1] != '\n')
+	    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+	  unix_cli_pager_prompt (cf, uf);
+	}
+      else
+	{
+	  if (action == UNIX_CLI_PARSE_ACTION_PAGER_NEXT)
+	    /* no more in buffer, exit, but only if it was <space> */
+	    goto pager_quit;
+	}
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_DN:
+    case UNIX_CLI_PARSE_ACTION_PAGER_CRLF:
+      /* display the next line of the buffer */
+      if (cf->pager_start < vec_len (cf->pager_index) - (cf->height - 1))
+	{
+	  u8 *line;
+	  unix_cli_pager_index_t *pi;
+
+	  unix_cli_pager_prompt_erase (cf, uf);
+	  pi = &cf->pager_index[cf->pager_start + (cf->height - 1)];
+	  line = cf->pager_vector[pi->line] + pi->offset;
+	  unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+	  cf->pager_start++;
+	  /* if the last line didn't end in newline, add a newline */
+	  if (line[pi->length - 1] != '\n')
+	    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+	  unix_cli_pager_prompt (cf, uf);
+	}
+      else
+	{
+	  if (action == UNIX_CLI_PARSE_ACTION_PAGER_CRLF)
+	    /* no more in buffer, exit, but only if it was <enter> */
+	    goto pager_quit;
+	}
+
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_UP:
+      /* scroll the page back one line */
+      if (cf->pager_start > 0)
+	{
+	  u8 *line = NULL;
+	  unix_cli_pager_index_t *pi = NULL;
+
+	  cf->pager_start--;
+	  if (cf->ansi_capable)
+	    {
+	      pi = &cf->pager_index[cf->pager_start];
+	      line = cf->pager_vector[pi->line] + pi->offset;
+	      unix_cli_pager_prompt_erase (cf, uf);
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) ANSI_SCROLLDN,
+					   sizeof (ANSI_SCROLLDN) - 1);
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) ANSI_SAVECURSOR,
+					   sizeof (ANSI_SAVECURSOR) - 1);
+	      unix_cli_ansi_cursor (cf, uf, 1, 1);
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) ANSI_CLEARLINE,
+					   sizeof (ANSI_CLEARLINE) - 1);
+	      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+	      unix_vlib_cli_output_cooked (cf, uf, (u8 *) ANSI_RESTCURSOR,
+					   sizeof (ANSI_RESTCURSOR) - 1);
+	      unix_cli_pager_prompt_erase (cf, uf);
+	      unix_cli_pager_prompt (cf, uf);
+	    }
+	  else
+	    {
+	      int m = cf->pager_start + (cf->height - 1);
+	      unix_cli_pager_prompt_erase (cf, uf);
+	      for (j = cf->pager_start;
+		   j < vec_len (cf->pager_index) && j < m; j++)
+		{
+		  pi = &cf->pager_index[j];
+		  line = cf->pager_vector[pi->line] + pi->offset;
+		  unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+		}
+	      /* if the last line didn't end in newline, add a newline */
+	      if (pi && line[pi->length - 1] != '\n')
+		unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+	      unix_cli_pager_prompt (cf, uf);
+	    }
+	}
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_TOP:
+      /* back to the first page of the buffer */
+      if (cf->pager_start > 0)
+	{
+	  u8 *line = NULL;
+	  unix_cli_pager_index_t *pi = NULL;
+
+	  cf->pager_start = 0;
+	  int m = cf->pager_start + (cf->height - 1);
+	  unix_cli_pager_prompt_erase (cf, uf);
+	  for (j = cf->pager_start; j < vec_len (cf->pager_index) && j < m;
+	       j++)
+	    {
+	      pi = &cf->pager_index[j];
+	      line = cf->pager_vector[pi->line] + pi->offset;
+	      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+	    }
+	  /* if the last line didn't end in newline, add a newline */
+	  if (pi && line[pi->length - 1] != '\n')
+	    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+	  unix_cli_pager_prompt (cf, uf);
+	}
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_BOTTOM:
+      /* skip to the last page of the buffer */
+      if (cf->pager_start < vec_len (cf->pager_index) - (cf->height - 1))
+	{
+	  u8 *line = NULL;
+	  unix_cli_pager_index_t *pi = NULL;
+
+	  cf->pager_start = vec_len (cf->pager_index) - (cf->height - 1);
+	  unix_cli_pager_prompt_erase (cf, uf);
+	  unix_cli_pager_message (cf, uf, "skipping", "\n");
+	  for (j = cf->pager_start; j < vec_len (cf->pager_index); j++)
+	    {
+	      pi = &cf->pager_index[j];
+	      line = cf->pager_vector[pi->line] + pi->offset;
+	      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+	    }
+	  /* if the last line didn't end in newline, add a newline */
+	  if (pi && line[pi->length - 1] != '\n')
+	    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+	  unix_cli_pager_prompt (cf, uf);
+	}
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_PGUP:
+      /* wander back one page in the buffer */
+      if (cf->pager_start > 0)
+	{
+	  u8 *line = NULL;
+	  unix_cli_pager_index_t *pi = NULL;
+	  int m;
+
+	  if (cf->pager_start >= cf->height)
+	    cf->pager_start -= cf->height - 1;
+	  else
+	    cf->pager_start = 0;
+	  m = cf->pager_start + cf->height - 1;
+	  unix_cli_pager_prompt_erase (cf, uf);
+	  for (j = cf->pager_start; j < vec_len (cf->pager_index) && j < m;
+	       j++)
+	    {
+	      pi = &cf->pager_index[j];
+	      line = cf->pager_vector[pi->line] + pi->offset;
+	      unix_vlib_cli_output_cooked (cf, uf, line, pi->length);
+	    }
+	  /* if the last line didn't end in newline, add a newline */
+	  if (pi && line[pi->length - 1] != '\n')
+	    unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+	  unix_cli_pager_prompt (cf, uf);
+	}
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_REDRAW:
+      /* Redraw the current pager screen */
+      unix_cli_pager_redraw (cf, uf);
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_PAGER_SEARCH:
+      /* search forwards in the buffer */
+      break;
+
+
+    case UNIX_CLI_PARSE_ACTION_CRLF:
+    crlf:
+      unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\n", 1);
+
+      if (cf->has_history && cf->history_limit)
+	{
+	  if (cf->command_history
+	      && vec_len (cf->command_history) >= cf->history_limit)
+	    {
+	      vec_free (cf->command_history[0]);
+	      vec_delete (cf->command_history, 1, 0);
+	    }
+	  /* Don't add blank lines to the cmd history */
+	  if (vec_len (cf->current_command))
+	    {
+	      /* Don't duplicate the previous command */
+	      j = vec_len (cf->command_history);
+	      if (j == 0 ||
+		  (vec_len (cf->current_command) !=
+		   vec_len (cf->command_history[j - 1])
+		   || memcmp (cf->current_command, cf->command_history[j - 1],
+			      vec_len (cf->current_command)) != 0))
+		{
+		  /* copy the command to the history */
+		  u8 *c = 0;
+		  vec_append (c, cf->current_command);
+		  vec_add1 (cf->command_history, c);
+		  cf->command_number++;
+		}
+	    }
+	  cf->excursion = vec_len (cf->command_history);
+	}
+
+      cf->search_mode = 0;
+      vec_reset_length (cf->search_key);
+      cf->cursor = 0;
+
+      return 0;
+
+    case UNIX_CLI_PARSE_ACTION_PARTIALMATCH:
+    case UNIX_CLI_PARSE_ACTION_NOMATCH:
+      if (vec_len (cf->pager_index))
+	{
+	  /* no-op for now */
+	}
+      else if (cf->has_history && cf->search_mode && isprint (input))
+	{
+	  int k, limit, offset;
+	  u8 *item;
+
+	  vec_add1 (cf->search_key, input);
+
+	search_again:
+	  for (j = 0; j < vec_len (cf->command_history); j++)
+	    {
+	      if (cf->excursion > (i32) vec_len (cf->command_history) - 1)
+		cf->excursion = 0;
+	      else if (cf->excursion < 0)
+		cf->excursion = vec_len (cf->command_history) - 1;
+
+	      item = cf->command_history[cf->excursion];
+
+	      limit = (vec_len (cf->search_key) > vec_len (item)) ?
+		vec_len (item) : vec_len (cf->search_key);
+
+	      for (offset = 0; offset <= vec_len (item) - limit; offset++)
+		{
+		  for (k = 0; k < limit; k++)
+		    {
+		      if (item[k + offset] != cf->search_key[k])
+			goto next_offset;
+		    }
+		  goto found_at_offset;
+
+		next_offset:
+		  ;
+		}
+	      goto next;
+
+	    found_at_offset:
+	      for (j = 0; j < vec_len (cf->current_command); j++)
+		unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\b \b", 3);
+
+	      vec_validate (cf->current_command, vec_len (item) - 1);
+	      clib_memcpy (cf->current_command, item, vec_len (item));
+	      _vec_len (cf->current_command) = vec_len (item);
+
+	      unix_vlib_cli_output_cooked (cf, uf, cf->current_command,
+					   vec_len (cf->current_command));
+	      cf->cursor = vec_len (cf->current_command);
+	      goto found;
+
+	    next:
+	      cf->excursion += cf->search_mode;
+	    }
+
+	  unix_vlib_cli_output_cooked (cf, uf, (u8 *) "\nNo match...", 12);
+	  vec_reset_length (cf->search_key);
+	  vec_reset_length (cf->current_command);
+	  cf->search_mode = 0;
+	  cf->cursor = 0;
+	  goto crlf;
+	}
+      else if (isprint (input))	/* skip any errant control codes */
+	{
+	  if (cf->cursor == vec_len (cf->current_command))
+	    {
+	      /* Append to end */
+	      vec_add1 (cf->current_command, input);
+	      cf->cursor++;
+
+	      /* Echo the character back to the client */
+	      unix_vlib_cli_output_raw (cf, uf, &input, 1);
+	    }
+	  else
+	    {
+	      /* Insert at cursor: resize +1 byte, move everything over */
+	      j = vec_len (cf->current_command) - cf->cursor;
+	      vec_add1 (cf->current_command, (u8) 'A');
+	      memmove (cf->current_command + cf->cursor + 1,
+		       cf->current_command + cf->cursor, j);
+	      cf->current_command[cf->cursor] = input;
+	      /* Redraw the line */
+	      j++;
+	      unix_vlib_cli_output_raw (cf, uf,
+					cf->current_command + cf->cursor, j);
+	      /* Put terminal cursor back */
+	      while (--j)
+		unix_vlib_cli_output_raw (cf, uf, (u8 *) "\b", 1);
+	      cf->cursor++;
+	    }
+	}
+      else
+	{
+	  /* no-op - not printable or otherwise not actionable */
+	}
+
+    found:
+
+      break;
+
+    case UNIX_CLI_PARSE_ACTION_TELNETIAC:
+      break;
+    }
+  return 1;
+}
+
+/** @brief Process input bytes on a stream to provide line editing and
+ * command history in the CLI. */
+static int
+unix_cli_line_edit (unix_cli_main_t * cm,
+		    unix_main_t * um, unix_cli_file_t * cf)
+{
+  unix_file_t *uf = pool_elt_at_index (um->file_pool, cf->unix_file_index);
+  int i;
+
+  for (i = 0; i < vec_len (cf->input_vector); i++)
+    {
+      unix_cli_parse_action_t action;
+      i32 matched = 0;
+      unix_cli_parse_actions_t *a;
+
+      /* If we're in the pager mode, search the pager actions */
+      a =
+	vec_len (cf->pager_index) ? unix_cli_parse_pager :
+	unix_cli_parse_strings;
+
+      /* See if the input buffer is some sort of control code */
+      action = unix_cli_match_action (a, &cf->input_vector[i],
+				      vec_len (cf->input_vector) - i,
+				      &matched);
+
+      switch (action)
+	{
+	case UNIX_CLI_PARSE_ACTION_PARTIALMATCH:
+	  if (i)
+	    {
+	      /* There was a partial match which means we need more bytes
+	       * than the input buffer currently has.
+	       * Since the bytes before here have been processed, shift
+	       * the remaining contents to the start of the input buffer.
+	       */
+	      vec_delete (cf->input_vector, i, 0);
+	    }
+	  return 1;		/* wait for more */
+
+	case UNIX_CLI_PARSE_ACTION_TELNETIAC:
+	  /* process telnet options */
+	  matched = unix_cli_process_telnet (um, cf, uf,
+					     cf->input_vector + i,
+					     vec_len (cf->input_vector) - i);
+	  if (matched < 0)
+	    {
+	      if (i)
+		{
+		  /* There was a partial match which means we need more bytes
+		   * than the input buffer currently has.
+		   * Since the bytes before here have been processed, shift
+		   * the remaining contents to the start of the input buffer.
+		   */
+		  vec_delete (cf->input_vector, i, 0);
+		}
+	      return 1;		/* wait for more */
+	    }
+	  break;
+
+	default:
+	  /* process the action */
+	  if (!unix_cli_line_process_one (cm, um, cf, uf,
+					  cf->input_vector[i], action))
+	    {
+	      /* CRLF found. Consume the bytes from the input_vector */
+	      vec_delete (cf->input_vector, i + matched, 0);
+	      /* And tell our caller to execute cf->input_command */
+	      return 0;
+	    }
+	}
+
+      i += matched;
+    }
+
+  vec_reset_length (cf->input_vector);
+  return 1;
+}
+
+/** @brief Process input to a CLI session. */
+static void
+unix_cli_process_input (unix_cli_main_t * cm, uword cli_file_index)
+{
+  unix_main_t *um = &unix_main;
+  unix_file_t *uf;
+  unix_cli_file_t *cf = pool_elt_at_index (cm->cli_file_pool, cli_file_index);
+  unformat_input_t input;
+  int vlib_parse_eval (u8 *);
+
+more:
+  /* Try vlibplex first.  Someday... */
+  if (0 && vlib_parse_eval (cf->input_vector) == 0)
+    goto done;
+
+  if (cf->line_mode)
+    {
+      /* just treat whatever we got as a complete line of input */
+      cf->current_command = cf->input_vector;
+    }
+  else
+    {
+      /* Line edit, echo, etc. */
+      if (unix_cli_line_edit (cm, um, cf))
+	/* want more input */
+	return;
+    }
+
+  if (um->log_fd)
+    {
+      static u8 *lv;
+      vec_reset_length (lv);
+      lv = format (lv, "%U[%d]: %v",
+		   format_timeval, 0 /* current bat-time */ ,
+		   0 /* current bat-format */ ,
+		   cli_file_index, cf->input_vector);
+      {
+	int rv __attribute__ ((unused)) =
+	  write (um->log_fd, lv, vec_len (lv));
+      }
+    }
+
+  /* Copy our input command to a new string */
+  unformat_init_vector (&input, cf->current_command);
+
+  /* Remove leading white space from input. */
+  (void) unformat (&input, "");
+
+  cm->current_input_file_index = cli_file_index;
+  cf->pager_start = 0;		/* start a new pager session */
+
+  if (unformat_check_input (&input) != UNFORMAT_END_OF_INPUT)
+    vlib_cli_input (um->vlib_main, &input, unix_vlib_cli_output,
+		    cli_file_index);
+
+  /* Zero buffer since otherwise unformat_free will call vec_free on it. */
+  input.buffer = 0;
+
+  unformat_free (&input);
+
+  /* Re-fetch pointer since pool may have moved. */
+  cf = pool_elt_at_index (cm->cli_file_pool, cli_file_index);
+  uf = pool_elt_at_index (um->file_pool, cf->unix_file_index);
+
+done:
+  /* reset vector; we'll re-use it later  */
+  if (cf->line_mode)
+    vec_reset_length (cf->input_vector);
+  else
+    vec_reset_length (cf->current_command);
+
+  if (cf->no_pager == 2)
+    {
+      /* Pager was programmatically disabled */
+      unix_cli_pager_message (cf, uf, "pager buffer overflowed", "\n");
+      cf->no_pager = um->cli_no_pager;
+    }
+
+  if (vec_len (cf->pager_index) == 0
+      || vec_len (cf->pager_index) < cf->height)
+    {
+      /* There was no need for the pager */
+      unix_cli_pager_reset (cf);
+
+      /* Prompt. */
+      unix_cli_cli_prompt (cf, uf);
+    }
+  else
+    {
+      /* Display the pager prompt */
+      unix_cli_pager_prompt (cf, uf);
+    }
+
+  /* Any residual data in the input vector? */
+  if (vec_len (cf->input_vector))
+    goto more;
+}
+
+/** Destroy a CLI session.
+ * @note If we destroy the @c stdin session this additionally signals
+ *       the shutdown of VPP.
+ */
+static void
+unix_cli_kill (unix_cli_main_t * cm, uword cli_file_index)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_file_t *cf;
+  unix_file_t *uf;
+  int i;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cli_file_index);
+  uf = pool_elt_at_index (um->file_pool, cf->unix_file_index);
+
+  /* Quit/EOF on stdin means quit program. */
+  if (uf->file_descriptor == UNIX_CLI_STDIN_FD)
+    clib_longjmp (&um->vlib_main->main_loop_exit, VLIB_MAIN_LOOP_EXIT_CLI);
+
+  vec_free (cf->current_command);
+  vec_free (cf->search_key);
+
+  for (i = 0; i < vec_len (cf->command_history); i++)
+    vec_free (cf->command_history[i]);
+
+  vec_free (cf->command_history);
+
+  unix_file_del (um, uf);
+
+  unix_cli_file_free (cf);
+  pool_put (cm->cli_file_pool, cf);
+}
+
+/** Handle system events. */
+static uword
+unix_cli_process (vlib_main_t * vm,
+		  vlib_node_runtime_t * rt, vlib_frame_t * f)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+  uword i, *data = 0;
+
+  while (1)
+    {
+      unix_cli_process_event_type_t event_type;
+      vlib_process_wait_for_event (vm);
+      event_type = vlib_process_get_events (vm, &data);
+
+      switch (event_type)
+	{
+	case UNIX_CLI_PROCESS_EVENT_READ_READY:
+	  for (i = 0; i < vec_len (data); i++)
+	    unix_cli_process_input (cm, data[i]);
+	  break;
+
+	case UNIX_CLI_PROCESS_EVENT_QUIT:
+	  /* Kill this process. */
+	  for (i = 0; i < vec_len (data); i++)
+	    unix_cli_kill (cm, data[i]);
+	  goto done;
+	}
+
+      if (data)
+	_vec_len (data) = 0;
+    }
+
+done:
+  vec_free (data);
+
+  vlib_node_set_state (vm, rt->node_index, VLIB_NODE_STATE_DISABLED);
+
+  /* Add node index so we can re-use this process later. */
+  vec_add1 (cm->unused_cli_process_node_indices, rt->node_index);
+
+  return 0;
+}
+
+/** Called when a CLI session file descriptor can be written to without
+ * blocking. */
+static clib_error_t *
+unix_cli_write_ready (unix_file_t * uf)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  int n;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, uf->private_data);
+
+  /* Flush output vector. */
+  n = write (uf->file_descriptor,
+	     cf->output_vector, vec_len (cf->output_vector));
+
+  if (n < 0 && errno != EAGAIN)
+    return clib_error_return_unix (0, "write");
+
+  else if (n > 0)
+    unix_cli_del_pending_output (uf, cf, n);
+
+  return /* no error */ 0;
+}
+
+/** Called when a CLI session file descriptor has data to be read. */
+static clib_error_t *
+unix_cli_read_ready (unix_file_t * uf)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  uword l;
+  int n, n_read, n_try;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, uf->private_data);
+
+  n = n_try = 4096;
+  while (n == n_try)
+    {
+      l = vec_len (cf->input_vector);
+      vec_resize (cf->input_vector, l + n_try);
+
+      n = read (uf->file_descriptor, cf->input_vector + l, n_try);
+
+      /* Error? */
+      if (n < 0 && errno != EAGAIN)
+	return clib_error_return_unix (0, "read");
+
+      n_read = n < 0 ? 0 : n;
+      _vec_len (cf->input_vector) = l + n_read;
+    }
+
+  if (!(n < 0))
+    vlib_process_signal_event (um->vlib_main,
+			       cf->process_node_index,
+			       (n_read == 0
+				? UNIX_CLI_PROCESS_EVENT_QUIT
+				: UNIX_CLI_PROCESS_EVENT_READ_READY),
+			       /* event data */ uf->private_data);
+
+  return /* no error */ 0;
+}
+
+/** Store a new CLI session.
+ * @param name The name of the session.
+ * @param fd   The file descriptor for the session I/O.
+ * @return The session ID.
+ */
+static u32
+unix_cli_file_add (unix_cli_main_t * cm, char *name, int fd)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_file_t *cf;
+  unix_file_t template = { 0 };
+  vlib_main_t *vm = um->vlib_main;
+  vlib_node_t *n;
+
+  name = (char *) format (0, "unix-cli-%s", name);
+
+  if (vec_len (cm->unused_cli_process_node_indices) > 0)
+    {
+      uword l = vec_len (cm->unused_cli_process_node_indices);
+
+      /* Find node and give it new name. */
+      n = vlib_get_node (vm, cm->unused_cli_process_node_indices[l - 1]);
+      vec_free (n->name);
+      n->name = (u8 *) name;
+
+      vlib_node_set_state (vm, n->index, VLIB_NODE_STATE_POLLING);
+
+      _vec_len (cm->unused_cli_process_node_indices) = l - 1;
+    }
+  else
+    {
+      static vlib_node_registration_t r = {
+	.function = unix_cli_process,
+	.type = VLIB_NODE_TYPE_PROCESS,
+	.process_log2_n_stack_bytes = 16,
+      };
+
+      r.name = name;
+      vlib_register_node (vm, &r);
+      vec_free (name);
+
+      n = vlib_get_node (vm, r.index);
+    }
+
+  pool_get (cm->cli_file_pool, cf);
+  memset (cf, 0, sizeof (*cf));
+
+  template.read_function = unix_cli_read_ready;
+  template.write_function = unix_cli_write_ready;
+  template.file_descriptor = fd;
+  template.private_data = cf - cm->cli_file_pool;
+
+  cf->process_node_index = n->index;
+  cf->unix_file_index = unix_file_add (um, &template);
+  cf->output_vector = 0;
+  cf->input_vector = 0;
+
+  vlib_start_process (vm, n->runtime_index);
+
+  vlib_process_t *p = vlib_get_process_from_node (vm, n);
+  p->output_function = unix_vlib_cli_output;
+  p->output_function_arg = cf - cm->cli_file_pool;
+
+  return cf - cm->cli_file_pool;
+}
+
+/** Telnet listening socket has a new connection. */
+static clib_error_t *
+unix_cli_listen_read_ready (unix_file_t * uf)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_main_t *cm = &unix_cli_main;
+  clib_socket_t *s = &um->cli_listen_socket;
+  clib_socket_t client;
+  char *client_name;
+  clib_error_t *error;
+  unix_cli_file_t *cf;
+  u32 cf_index;
+
+  error = clib_socket_accept (s, &client);
+  if (error)
+    return error;
+
+  client_name = (char *) format (0, "%U%c", format_sockaddr, &client.peer, 0);
+
+  cf_index = unix_cli_file_add (cm, client_name, client.fd);
+  cf = pool_elt_at_index (cm->cli_file_pool, cf_index);
+
+  /* No longer need CLIB version of socket. */
+  clib_socket_free (&client);
+
+  vec_free (client_name);
+
+  /* if we're supposed to run telnet session in character mode (default) */
+  if (um->cli_line_mode == 0)
+    {
+      /*
+       * Set telnet client character mode, echo on, suppress "go-ahead".
+       * Technically these should be negotiated, but this works.
+       */
+      u8 charmode_option[] = {
+	IAC, WONT, TELOPT_LINEMODE,	/* server will do char-by-char */
+	IAC, DONT, TELOPT_LINEMODE,	/* client should do char-by-char */
+	IAC, WILL, TELOPT_SGA,	/* server willl supress GA */
+	IAC, DO, TELOPT_SGA,	/* client should supress Go Ahead */
+	IAC, WILL, TELOPT_ECHO,	/* server will do echo */
+	IAC, DONT, TELOPT_ECHO,	/* client should not echo */
+	IAC, DO, TELOPT_TTYPE,	/* client should tell us its term type */
+	IAC, SB, TELOPT_TTYPE, 1, IAC, SE,	/* now tell me ttype */
+	IAC, DO, TELOPT_NAWS,	/* client should tell us its window sz */
+	IAC, SB, TELOPT_NAWS, 1, IAC, SE,	/* now tell me window size */
+      };
+
+      /* Enable history on this CLI */
+      cf->history_limit = um->cli_history_limit;
+      cf->has_history = cf->history_limit != 0;
+
+      /* Make sure this session is in line mode */
+      cf->line_mode = 0;
+
+      /* We need CRLF */
+      cf->crlf_mode = 1;
+
+      /* Setup the pager */
+      cf->no_pager = um->cli_no_pager;
+
+      uf = pool_elt_at_index (um->file_pool, cf->unix_file_index);
+
+      /* Send the telnet options */
+      unix_vlib_cli_output_raw (cf, uf, charmode_option,
+				ARRAY_LEN (charmode_option));
+
+      /* In case the client doesn't negotiate terminal type, use
+       * a timer to kick off the initial prompt. */
+      timer_call (unix_cli_file_welcome_timer, cf_index, 1);
+    }
+
+  return error;
+}
+
+/** The system terminal has informed us that the window size
+ * has changed.
+ */
+static void
+unix_cli_resize_interrupt (int signum)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf = pool_elt_at_index (cm->cli_file_pool,
+					   cm->stdin_cli_file_index);
+  unix_file_t *uf = pool_elt_at_index (um->file_pool, cf->unix_file_index);
+  struct winsize ws;
+  (void) signum;
+
+  /* Terminal resized, fetch the new size */
+  if (ioctl (UNIX_CLI_STDIN_FD, TIOCGWINSZ, &ws) < 0)
+    {
+      /* "Should never happen..." */
+      clib_unix_warning ("TIOCGWINSZ");
+      /* We can't trust ws.XXX... */
+      return;
+    }
+  cf->width = ws.ws_col;
+  cf->height = ws.ws_row;
+
+  /* Reindex the pager buffer */
+  unix_cli_pager_reindex (cf);
+
+  /* Redraw the page */
+  unix_cli_pager_redraw (cf, uf);
+}
+
+/** Handle configuration directives in the @em unix section. */
+static clib_error_t *
+unix_cli_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_main_t *cm = &unix_cli_main;
+  int flags;
+  clib_error_t *error = 0;
+  unix_cli_file_t *cf;
+  u32 cf_index;
+  struct termios tio;
+  struct sigaction sa;
+  struct winsize ws;
+  u8 *term;
+
+  /* We depend on unix flags being set. */
+  if ((error = vlib_call_config_function (vm, unix_config)))
+    return error;
+
+  if (um->flags & UNIX_FLAG_INTERACTIVE)
+    {
+      /* Set stdin to be non-blocking. */
+      if ((flags = fcntl (UNIX_CLI_STDIN_FD, F_GETFL, 0)) < 0)
+	flags = 0;
+      (void) fcntl (UNIX_CLI_STDIN_FD, F_SETFL, flags | O_NONBLOCK);
+
+      cf_index = unix_cli_file_add (cm, "stdin", UNIX_CLI_STDIN_FD);
+      cf = pool_elt_at_index (cm->cli_file_pool, cf_index);
+      cm->stdin_cli_file_index = cf_index;
+
+      /* If stdin is a tty and we are using chacracter mode, enable
+       * history on the CLI and set the tty line discipline accordingly. */
+      if (isatty (UNIX_CLI_STDIN_FD) && um->cli_line_mode == 0)
+	{
+	  /* Capture terminal resize events */
+	  memset (&sa, 0, sizeof (sa));
+	  sa.sa_handler = unix_cli_resize_interrupt;
+	  if (sigaction (SIGWINCH, &sa, 0) < 0)
+	    clib_panic ("sigaction");
+
+	  /* Retrieve the current terminal size */
+	  ioctl (UNIX_CLI_STDIN_FD, TIOCGWINSZ, &ws);
+	  cf->width = ws.ws_col;
+	  cf->height = ws.ws_row;
+
+	  if (cf->width == 0 || cf->height == 0)
+	    /* We have a tty, but no size. Stick to line mode. */
+	    goto notty;
+
+	  /* Setup the history */
+	  cf->history_limit = um->cli_history_limit;
+	  cf->has_history = cf->history_limit != 0;
+
+	  /* Setup the pager */
+	  cf->no_pager = um->cli_no_pager;
+
+	  /* We're going to be in char by char mode */
+	  cf->line_mode = 0;
+
+	  /* Save the original tty state so we can restore it later */
+	  tcgetattr (UNIX_CLI_STDIN_FD, &um->tio_stdin);
+	  um->tio_isset = 1;
+
+	  /* Tweak the tty settings */
+	  tio = um->tio_stdin;
+	  /* echo off, canonical mode off, ext'd input processing off */
+	  tio.c_lflag &= ~(ECHO | ICANON | IEXTEN);
+	  tio.c_cc[VMIN] = 1;	/* 1 byte at a time */
+	  tio.c_cc[VTIME] = 0;	/* no timer */
+	  tcsetattr (UNIX_CLI_STDIN_FD, TCSAFLUSH, &tio);
+
+	  /* See if we can do ANSI/VT100 output */
+	  term = (u8 *) getenv ("TERM");
+	  if (term != NULL)
+	    cf->ansi_capable = unix_cli_terminal_type (term,
+						       strlen ((char *)
+							       term));
+	}
+      else
+	{
+	notty:
+	  /* No tty, so make sure these things are off */
+	  cf->no_pager = 1;
+	  cf->history_limit = 0;
+	  cf->has_history = 0;
+	  cf->line_mode = 1;
+	}
+
+      /* Send banner and initial prompt */
+      unix_cli_file_welcome (cm, cf);
+    }
+
+  /* If we have socket config, LISTEN, otherwise, don't */
+  clib_socket_t *s = &um->cli_listen_socket;
+  if (s->config && s->config[0] != 0)
+    {
+      /* CLI listen. */
+      unix_file_t template = { 0 };
+
+      s->flags = SOCKET_IS_SERVER;	/* listen, don't connect */
+      error = clib_socket_init (s);
+
+      if (error)
+	return error;
+
+      template.read_function = unix_cli_listen_read_ready;
+      template.file_descriptor = s->fd;
+
+      unix_file_add (um, &template);
+    }
+
+  /* Set CLI prompt. */
+  if (!cm->cli_prompt)
+    cm->cli_prompt = format (0, "VLIB: ");
+
+  return 0;
+}
+
+/*?
+ * This module has no configurable parameters.
+?*/
+VLIB_CONFIG_FUNCTION (unix_cli_config, "unix-cli");
+
+/** Called when VPP is shutting down, this restores the system
+ * terminal state if previously saved.
+ */
+static clib_error_t *
+unix_cli_exit (vlib_main_t * vm)
+{
+  unix_main_t *um = &unix_main;
+
+  /* If stdin is a tty and we saved the tty state, reset the tty state */
+  if (isatty (UNIX_CLI_STDIN_FD) && um->tio_isset)
+    tcsetattr (UNIX_CLI_STDIN_FD, TCSAFLUSH, &um->tio_stdin);
+
+  return 0;
+}
+
+VLIB_MAIN_LOOP_EXIT_FUNCTION (unix_cli_exit);
+
+/** Set the CLI prompt.
+ * @param prompt The C string to set the prompt to.
+ * @note This setting is global; it impacts all current
+ *       and future CLI sessions.
+ */
+void
+vlib_unix_cli_set_prompt (char *prompt)
+{
+  char *fmt = (prompt[strlen (prompt) - 1] == ' ') ? "%s" : "%s ";
+  unix_cli_main_t *cm = &unix_cli_main;
+  if (cm->cli_prompt)
+    vec_free (cm->cli_prompt);
+  cm->cli_prompt = format (0, fmt, prompt);
+}
+
+/** CLI command to quit the terminal session.
+ * @note If this is a stdin session then this will
+ *       shutdown VPP also.
+ */
+static clib_error_t *
+unix_cli_quit (vlib_main_t * vm,
+	       unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+
+  vlib_process_signal_event (vm,
+			     vlib_current_process (vm),
+			     UNIX_CLI_PROCESS_EVENT_QUIT,
+			     cm->current_input_file_index);
+  return 0;
+}
+
+/*?
+ * Terminates the current CLI session.
+ *
+ * If VPP is running in @em interactive mode and this is the console session
+ * (that is, the session on @c stdin) then this will also terminate VPP.
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (unix_cli_quit_command, static) = {
+  .path = "quit",
+  .short_help = "Exit CLI",
+  .function = unix_cli_quit,
+};
+/* *INDENT-ON* */
+
+/** CLI command to execute a VPP command script. */
+static clib_error_t *
+unix_cli_exec (vlib_main_t * vm,
+	       unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  char *file_name;
+  int fd;
+  unformat_input_t sub_input;
+  clib_error_t *error;
+
+  file_name = 0;
+  fd = -1;
+  error = 0;
+
+  if (!unformat (input, "%s", &file_name))
+    {
+      error = clib_error_return (0, "expecting file name, got `%U'",
+				 format_unformat_error, input);
+      goto done;
+    }
+
+  fd = open (file_name, O_RDONLY);
+  if (fd < 0)
+    {
+      error = clib_error_return_unix (0, "failed to open `%s'", file_name);
+      goto done;
+    }
+
+  /* Make sure its a regular file. */
+  {
+    struct stat s;
+
+    if (fstat (fd, &s) < 0)
+      {
+	error = clib_error_return_unix (0, "failed to stat `%s'", file_name);
+	goto done;
+      }
+
+    if (!(S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
+      {
+	error = clib_error_return (0, "not a regular file `%s'", file_name);
+	goto done;
+      }
+  }
+
+  unformat_init_unix_file (&sub_input, fd);
+
+  vlib_cli_input (vm, &sub_input, 0, 0);
+  unformat_free (&sub_input);
+
+done:
+  if (fd > 0)
+    close (fd);
+  vec_free (file_name);
+
+  return error;
+}
+
+/*?
+ * Executes a sequence of CLI commands which are read from a file.
+ *
+ * If a command is unrecognised or otherwise invalid then the usual CLI
+ * feedback will be generated, however execution of subsequent commands
+ * from the file will continue.
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_exec, static) = {
+  .path = "exec",
+  .short_help = "Execute commands from file",
+  .function = unix_cli_exec,
+  .is_mp_safe = 1,
+};
+/* *INDENT-ON* */
+
+/** CLI command to show various unix error statistics. */
+static clib_error_t *
+unix_show_errors (vlib_main_t * vm,
+		  unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  unix_main_t *um = &unix_main;
+  clib_error_t *error = 0;
+  int i, n_errors_to_show;
+  unix_error_history_t *unix_errors = 0;
+
+  n_errors_to_show = 1 << 30;
+
+  if (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (!unformat (input, "%d", &n_errors_to_show))
+	{
+	  error =
+	    clib_error_return (0,
+			       "expecting integer number of errors to show, got `%U'",
+			       format_unformat_error, input);
+	  goto done;
+	}
+    }
+
+  n_errors_to_show =
+    clib_min (ARRAY_LEN (um->error_history), n_errors_to_show);
+
+  i =
+    um->error_history_index >
+    0 ? um->error_history_index - 1 : ARRAY_LEN (um->error_history) - 1;
+
+  while (n_errors_to_show > 0)
+    {
+      unix_error_history_t *eh = um->error_history + i;
+
+      if (!eh->error)
+	break;
+
+      vec_add1 (unix_errors, eh[0]);
+      n_errors_to_show -= 1;
+      if (i == 0)
+	i = ARRAY_LEN (um->error_history) - 1;
+      else
+	i--;
+    }
+
+  if (vec_len (unix_errors) == 0)
+    vlib_cli_output (vm, "no Unix errors so far");
+  else
+    {
+      vlib_cli_output (vm, "%Ld total errors seen", um->n_total_errors);
+      for (i = vec_len (unix_errors) - 1; i >= 0; i--)
+	{
+	  unix_error_history_t *eh = vec_elt_at_index (unix_errors, i);
+	  vlib_cli_output (vm, "%U: %U",
+			   format_time_interval, "h:m:s:u", eh->time,
+			   format_clib_error, eh->error);
+	}
+      vlib_cli_output (vm, "%U: time now",
+		       format_time_interval, "h:m:s:u", vlib_time_now (vm));
+    }
+
+done:
+  vec_free (unix_errors);
+  return error;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_unix_show_errors, static) = {
+  .path = "show unix-errors",
+  .short_help = "Show Unix system call error history",
+  .function = unix_show_errors,
+};
+/* *INDENT-ON* */
+
+/** CLI command to show session command history. */
+static clib_error_t *
+unix_cli_show_history (vlib_main_t * vm,
+		       unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  int i, j;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cm->current_input_file_index);
+
+  if (cf->has_history && cf->history_limit)
+    {
+      i = 1 + cf->command_number - vec_len (cf->command_history);
+      for (j = 0; j < vec_len (cf->command_history); j++)
+	vlib_cli_output (vm, "%d  %v\n", i + j, cf->command_history[j]);
+    }
+  else
+    {
+      vlib_cli_output (vm, "History not enabled.\n");
+    }
+
+  return 0;
+}
+
+/*?
+ * Displays the command history for the current session, if any.
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_unix_cli_show_history, static) = {
+  .path = "history",
+  .short_help = "Show current session command history",
+  .function = unix_cli_show_history,
+};
+/* *INDENT-ON* */
+
+/** CLI command to show terminal status. */
+static clib_error_t *
+unix_cli_show_terminal (vlib_main_t * vm,
+			unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  vlib_node_t *n;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cm->current_input_file_index);
+  n = vlib_get_node (vm, cf->process_node_index);
+
+  vlib_cli_output (vm, "Terminal name:   %v\n", n->name);
+  vlib_cli_output (vm, "Terminal mode:   %s\n", cf->line_mode ?
+		   "line-by-line" : "char-by-char");
+  vlib_cli_output (vm, "Terminal width:  %d\n", cf->width);
+  vlib_cli_output (vm, "Terminal height: %d\n", cf->height);
+  vlib_cli_output (vm, "ANSI capable:    %s\n",
+		   cf->ansi_capable ? "yes" : "no");
+  vlib_cli_output (vm, "History enabled: %s%s\n",
+		   cf->has_history ? "yes" : "no", !cf->has_history
+		   || cf->history_limit ? "" :
+		   " (disabled by history limit)");
+  if (cf->has_history)
+    vlib_cli_output (vm, "History limit:   %d\n", cf->history_limit);
+  vlib_cli_output (vm, "Pager enabled:   %s%s%s\n",
+		   cf->no_pager ? "no" : "yes",
+		   cf->no_pager
+		   || cf->height ? "" : " (disabled by terminal height)",
+		   cf->no_pager
+		   || um->cli_pager_buffer_limit ? "" :
+		   " (disabled by buffer limit)");
+  if (!cf->no_pager)
+    vlib_cli_output (vm, "Pager limit:     %d\n", um->cli_pager_buffer_limit);
+  vlib_cli_output (vm, "CRLF mode:       %s\n",
+		   cf->crlf_mode ? "CR+LF" : "LF");
+
+  return 0;
+}
+
+/*?
+ * Displays various information about the state of the current terminal
+ * session.
+ *
+ * @cliexpar
+ * @cliexstart{show terminal}
+ * Terminal name:   unix-cli-stdin
+ * Terminal mode:   char-by-char
+ * Terminal width:  123
+ * Terminal height: 48
+ * ANSI capable:    yes
+ * History enabled: yes
+ * History limit:   50
+ * Pager enabled:   yes
+ * Pager limit:     100000
+ * CRLF mode:       LF
+ * @cliexend
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_unix_cli_show_terminal, static) = {
+  .path = "show terminal",
+  .short_help = "Show current session terminal settings",
+  .function = unix_cli_show_terminal,
+};
+/* *INDENT-ON* */
+
+/** CLI command to set terminal pager settings. */
+static clib_error_t *
+unix_cli_set_terminal_pager (vlib_main_t * vm,
+			     unformat_input_t * input,
+			     vlib_cli_command_t * cmd)
+{
+  unix_main_t *um = &unix_main;
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  unformat_input_t _line_input, *line_input = &_line_input;
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cm->current_input_file_index);
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "on"))
+	cf->no_pager = 0;
+      else if (unformat (line_input, "off"))
+	cf->no_pager = 1;
+      else if (unformat (line_input, "limit %u", &um->cli_pager_buffer_limit))
+	vlib_cli_output (vm,
+			 "Pager limit set to %u lines; note, this is global.\n",
+			 um->cli_pager_buffer_limit);
+      else
+	return clib_error_return (0, "unknown parameter: `%U`",
+				  format_unformat_error, line_input);
+    }
+
+  unformat_free (line_input);
+
+  return 0;
+}
+
+/*?
+ * Enables or disables the terminal pager for this session. Generally
+ * this defaults to enabled.
+ *
+ * Additionally allows the pager buffer size to be set; though note that
+ * this value is set globally and not per session.
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_unix_cli_set_terminal_pager, static) = {
+  .path = "set terminal pager",
+  .short_help = "set terminal pager [on|off] [limit <lines>]",
+  .function = unix_cli_set_terminal_pager,
+};
+/* *INDENT-ON* */
+
+/** CLI command to set terminal history settings. */
+static clib_error_t *
+unix_cli_set_terminal_history (vlib_main_t * vm,
+			       unformat_input_t * input,
+			       vlib_cli_command_t * cmd)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  u32 limit;
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cm->current_input_file_index);
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "on"))
+	cf->has_history = 1;
+      else if (unformat (line_input, "off"))
+	cf->has_history = 0;
+      else if (unformat (line_input, "limit %u", &cf->history_limit))
+	;
+      else
+	return clib_error_return (0, "unknown parameter: `%U`",
+				  format_unformat_error, line_input);
+
+      /* If we reduced history size, or turned it off, purge the history */
+      limit = cf->has_history ? cf->history_limit : 0;
+
+      while (cf->command_history && vec_len (cf->command_history) >= limit)
+	{
+	  vec_free (cf->command_history[0]);
+	  vec_delete (cf->command_history, 1, 0);
+	}
+    }
+
+  unformat_free (line_input);
+
+  return 0;
+}
+
+/*?
+ * Enables or disables the command history function of the current
+ * terminal. Generally this defaults to enabled.
+ *
+ * This command also allows the maximum size of the history buffer for
+ * this session to be altered.
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_unix_cli_set_terminal_history, static) = {
+  .path = "set terminal history",
+  .short_help = "set terminal history [on|off] [limit <lines>]",
+  .function = unix_cli_set_terminal_history,
+};
+/* *INDENT-ON* */
+
+/** CLI command to set terminal ANSI settings. */
+static clib_error_t *
+unix_cli_set_terminal_ansi (vlib_main_t * vm,
+			    unformat_input_t * input,
+			    vlib_cli_command_t * cmd)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+  unix_cli_file_t *cf;
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cm->current_input_file_index);
+
+  if (unformat (input, "on"))
+    cf->ansi_capable = 1;
+  else if (unformat (input, "off"))
+    cf->ansi_capable = 0;
+  else
+    return clib_error_return (0, "unknown parameter: `%U`",
+			      format_unformat_error, input);
+
+  return 0;
+}
+
+/*?
+ * Enables or disables the use of ANSI control sequences by this terminal.
+ * The default will vary based on terminal detection at the start of the
+ * session.
+ *
+ * ANSI control sequences are used in a small number of places to provide,
+ * for example, color text output and to control the cursor in the pager.
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_unix_cli_set_terminal_ansi, static) = {
+  .path = "set terminal ansi",
+  .short_help = "set terminal ansi [on|off]",
+  .function = unix_cli_set_terminal_ansi,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+unix_cli_init (vlib_main_t * vm)
+{
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (unix_cli_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */