1 files changed, 54 insertions, 0 deletions
diff --git a/src/string/str/strcncpy.c b/src/string/str/strcncpy.c
new file mode 100644
index 0000000..5036c7d
--- /dev/null
+++ b/src/string/str/strcncpy.c
@@ -0,0 +1,54 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <string.h>
+
+
+
+/**
+ * Copy a memory segment to another, non-overlapping, segment,
+ * stop when a NUL byte or a specified byte is encountered.
+ * 
+ * This is a slibc extension added for completeness.
+ * It is only available if GNU extensions are available.
+ * 
+ * @param   whither  The destination memory segment.
+ * @param   whence   The source memory segment.
+ * @param   c        The stop byte.
+ * @param   maxlen   The maximum number of bytes to copy.
+ *                   NOTE that if the resulting string at least this
+ *                   long, no NUL byte will be written to `whither'.
+ *                   On the otherhand, if the resultnig string is
+ *                   shorter, `whither` will be filled with NUL bytes
+ *                   until this amount of bytes have been written.
+ * @return           `NULL` if `c` was not encountered, otherwise
+ *                   the position of `c` translated to `whither`,
+ *                   that is, the address of `whither` plus the
+ *                   number of copied characters; the address of
+ *                   one character passed the last written non-NUL
+ *                   character.
+ */
+char* strcncpy(char* restrict whither, const char* restrict whence, int c, size_t maxlen)
+{
+  const char* stop = memchr(whence, c, maxlen);
+  size_t n = stop == NULL ? strnlen(whence, maxlen) : (size_t)(stop - whence);
+  char* r = stop == NULL ? NULL : (whither + n);
+  memcpy(whither, whence, n);
+  memset(whither, 0, maxlen - n);
+  return r;
+}
+