vppinfra: add clib_file_get_resolved_basename

more generic version of clib_sysfs_link_to_name with support for
format strings...

Type: improvement
Change-Id: I0cb263748970378c661415196eb7e08450370677
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/vppinfra/unix-misc.c b/src/vppinfra/unix-misc.c
index e73d01a15d6..0c5d96c6bb7 100644
--- a/src/vppinfra/unix-misc.c
+++ b/src/vppinfra/unix-misc.c
@@ -38,12 +38,14 @@
 #include <vppinfra/error.h>
 #include <vppinfra/os.h>
 #include <vppinfra/unix.h>
+#include <vppinfra/format.h>
 
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/uio.h>		/* writev */
 #include <fcntl.h>
 #include <stdio.h>		/* for sprintf */
+#include <limits.h>
 
 __clib_export __thread uword __os_thread_index = 0;
 __clib_export __thread uword __os_numa_index = 0;
@@ -131,6 +133,35 @@ clib_file_contents (char *file, u8 ** result)
   return error;
 }
 
+__clib_export u8 *
+clib_file_get_resolved_basename (char *fmt, ...)
+{
+  va_list va;
+  char *p, buffer[PATH_MAX];
+  u8 *link, *s = 0;
+  int r;
+
+  va_start (va, fmt);
+  link = va_format (0, fmt, &va);
+  va_end (va);
+  vec_add1 (link, 0);
+
+  r = readlink ((char *) link, buffer, sizeof (buffer) - 1);
+  vec_free (link);
+
+  if (r < 1)
+    return 0;
+
+  p = buffer + r - 1;
+  while (p > buffer && p[-1] != '/')
+    p--;
+
+  while (p[0])
+    vec_add1 (s, p++[0]);
+
+  return s;
+}
+
 clib_error_t *
 unix_proc_file_contents (char *file, u8 ** result)
 {