daemon: Add a trim utility function.

This function trims the whitespace from around a string.  It
does this in-place, so it can be called for malloc'd strings.

2 files changed, 24 insertions, 0 deletions

diff --git a/daemon/daemon.h b/daemon/daemon.h
index bb1ebb3a..777cf332 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -66,6 +66,8 @@ extern int commandrvf (char **stdoutput, char **stderror, int flags,
 
 extern char **split_lines (char *str);
 
+extern void trim (char *str);
+
 extern int device_name_translation (char *device, const char *func);
 
 extern void udev_settle (void);
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index 0fc01283..5265ab52 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -928,6 +928,28 @@ split_lines (char *str)
   return lines;
 }
 
+/* Skip leading and trailing whitespace, updating the original string
+ * in-place.
+ */
+void
+trim (char *str)
+{
+  size_t len = strlen (str);
+
+  while (len > 0 && c_isspace (str[len-1])) {
+    str[len-1] = '\0';
+    len--;
+  }
+
+  const char *p = str;
+  while (*p && c_isspace (*p)) {
+    p++;
+    len--;
+  }
+
+  memmove (str, p, len+1);
+}
+
 /* printf helper function so we can use %Q ("quoted") and %R to print
  * shell-quoted strings.  See HACKING file for more details.
  */