daemon: New utility functions 'join_strings', 'concat_strings'.

Useful functions for concatenating strings together.

(cherry picked from commit 637b06ab1384f0c904715ba76fc759dac1b95500)

1 files changed, 41 insertions, 0 deletions

diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index e1645a02..f888cdc6 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -574,6 +574,47 @@ sort_device_names (char **argv, size_t len)
   qsort (argv, len, sizeof (char *), compare_device_names_vp);
 }
 
+char *
+concat_strings (char *const *argv)
+{
+  return join_strings ("", argv);
+}
+
+char *
+join_strings (const char *separator, char *const *argv)
+{
+  size_t i, len, seplen, rlen;
+  char *r;
+
+  seplen = strlen (separator);
+
+  len = 0;
+  for (i = 0; argv[i] != NULL; ++i) {
+    if (i > 0)
+      len += seplen;
+    len += strlen (argv[i]);
+  }
+  len++; /* for final \0 */
+
+  r = malloc (len);
+  if (r == NULL)
+    return NULL;
+
+  rlen = 0;
+  for (i = 0; argv[i] != NULL; ++i) {
+    if (i > 0) {
+      memcpy (&r[rlen], separator, seplen);
+      rlen += seplen;
+    }
+    len = strlen (argv[i]);
+    memcpy (&r[rlen], argv[i], len);
+    rlen += len;
+  }
+  r[rlen] = '\0';
+
+  return r;
+}
+
 /* Easy ways to run external commands.  For full documentation, see
  * 'commandrvf' below.
  */