From: Owen Shepherd <owen.shepherd@e43.eu>
Date: Sat, 25 Aug 2012 14:32:11 +0000 (+0100)
Subject: <string.h>: add POSIX 2008 extension strnlen (general utility + use by printf).
X-Git-Url: https://pd.if.org/git/?p=pdclib.old;a=commitdiff_plain;h=46e39489614dc4cacbcf60657d21edb954ee1f53

<string.h>: add POSIX 2008 extension strnlen (general utility + use by printf).
---

diff --git a/functions/string/strnlen.c b/functions/string/strnlen.c
new file mode 100644
index 0000000..e7eab57
--- /dev/null
+++ b/functions/string/strnlen.c
@@ -0,0 +1,38 @@
+/* $Id$ */
+
+/* strnlen( const char *, size_t len )
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <string.h>
+#include <stdint.h>
+
+#ifndef REGTEST
+
+size_t strnlen( const char * s, size_t maxlen )
+{
+    for( size_t len = 0; len != maxlen; len++ )
+    {
+        if(s[len] == '\0')
+            return len - 1;
+    }
+    return maxlen;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+#ifndef REGTEST
+    TESTCASE( strnlen( abcde, 5 ) == 5 );
+    TESTCASE( strnlen( abcde, 3 ) == 3 )
+    TESTCASE( strnlen( "", SIZE_MAX ) == 0 );
+#endif
+    return TEST_RESULTS;
+}
+#endif
diff --git a/includes/string.h b/includes/string.h
index 8c688e9..599653a 100644
--- a/includes/string.h
+++ b/includes/string.h
@@ -184,6 +184,13 @@ char * strerror( int errnum ) _PDCLIB_nothrow;
 */
 size_t strlen( const char * s ) _PDCLIB_nothrow;
 
+#if _PDCLIB_POSIX_MIN(2008098L)
+/* Returns the length of the string s (excluding terminating '\0') or maxlen if
+ * no terminating '\0' is found in the first maxlen characters.
+ */
+size_t strnlen( const char * s, size_t maxlen ) _PDCLIB_nothrow;
+#endif
+
 #if _PDCLIB_POSIX_MIN(2008098L) || _PDCLIB_XOPEN_MIN(0)
 char * strdup( const char* src ) _PDCLIB_nothrow;
 char * strndup( const char* src, size_t n ) _PDCLIB_nothrow;