aboutsummaryrefslogtreecommitdiff
path: root/strlcat.c
diff options
context:
space:
mode:
Diffstat (limited to 'strlcat.c')
-rw-r--r--strlcat.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/strlcat.c b/strlcat.c
new file mode 100644
index 0000000..bc523fb
--- /dev/null
+++ b/strlcat.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+#include "util.h"
+
+/*
+ * Appends src to string dst of size dsize (unlike strncat, dsize is the
+ * full size of dst, not space left). At most dsize-1 characters
+ * will be copied. Always NUL terminates (unless dsize <= strlen(dst)).
+ * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
+ * If retval >= dsize, truncation occurred.
+ */
+size_t
+strlcat(char *dst, const char *src, size_t dsize)
+{
+ const char *odst = dst;
+ const char *osrc = src;
+ size_t n = dsize;
+ size_t dlen;
+
+ /* Find the end of dst and adjust bytes left but don't go past end. */
+ while (n-- != 0 && *dst != '\0')
+ dst++;
+ dlen = dst - odst;
+ n = dsize - dlen;
+
+ if (n-- == 0)
+ return(dlen + strlen(src));
+ while (*src != '\0') {
+ if (n != 0) {
+ *dst++ = *src;
+ n--;
+ }
+ src++;
+ }
+ *dst = '\0';
+
+ return(dlen + (src - osrc)); /* count does not include NUL */
+}