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authortcsullivan <tullivan99@gmail.com>2018-11-17 13:02:57 -0500
committertcsullivan <tullivan99@gmail.com>2018-11-17 13:02:57 -0500
commitc6ef89664b8c0d7aa85bddd5c7014aa6df82cbe7 (patch)
treed1f9d09412a46bdf4344fe30392455070a72993d /src/pdclib/functions/string/strncpy.c
parentdb38c4b9dac461de0ed75bf6d079dacba1b31bc9 (diff)
added pdclib, removed sash
Diffstat (limited to 'src/pdclib/functions/string/strncpy.c')
-rw-r--r--src/pdclib/functions/string/strncpy.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/src/pdclib/functions/string/strncpy.c b/src/pdclib/functions/string/strncpy.c
new file mode 100644
index 0000000..0627c41
--- /dev/null
+++ b/src/pdclib/functions/string/strncpy.c
@@ -0,0 +1,56 @@
+/* strncpy( char *, const char *, size_t )
+
+ 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>
+
+#ifndef REGTEST
+
+char * strncpy( char * _PDCLIB_restrict s1, const char * _PDCLIB_restrict s2, size_t n )
+{
+ char * rc = s1;
+ while ( n && ( *s1++ = *s2++ ) )
+ {
+ /* Cannot do "n--" in the conditional as size_t is unsigned and we have
+ to check it again for >0 in the next loop below, so we must not risk
+ underflow.
+ */
+ --n;
+ }
+ /* Checking against 1 as we missed the last --n in the loop above. */
+ while ( n-- > 1 )
+ {
+ *s1++ = '\0';
+ }
+ return rc;
+}
+
+#endif
+
+#ifdef TEST
+
+#include "_PDCLIB_test.h"
+
+int main( void )
+{
+ char s[] = "xxxxxxx";
+ TESTCASE( strncpy( s, "", 1 ) == s );
+ TESTCASE( s[0] == '\0' );
+ TESTCASE( s[1] == 'x' );
+ TESTCASE( strncpy( s, abcde, 6 ) == s );
+ TESTCASE( s[0] == 'a' );
+ TESTCASE( s[4] == 'e' );
+ TESTCASE( s[5] == '\0' );
+ TESTCASE( s[6] == 'x' );
+ TESTCASE( strncpy( s, abcde, 7 ) == s );
+ TESTCASE( s[6] == '\0' );
+ TESTCASE( strncpy( s, "xxxx", 3 ) == s );
+ TESTCASE( s[0] == 'x' );
+ TESTCASE( s[2] == 'x' );
+ TESTCASE( s[3] == 'd' );
+ return TEST_RESULTS;
+}
+
+#endif