diff options
author | tcsullivan <tullivan99@gmail.com> | 2018-11-17 13:02:57 -0500 |
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committer | tcsullivan <tullivan99@gmail.com> | 2018-11-17 13:02:57 -0500 |
commit | c6ef89664b8c0d7aa85bddd5c7014aa6df82cbe7 (patch) | |
tree | d1f9d09412a46bdf4344fe30392455070a72993d /src/pdclib/functions/string/strncpy.c | |
parent | db38c4b9dac461de0ed75bf6d079dacba1b31bc9 (diff) |
added pdclib, removed sash
Diffstat (limited to 'src/pdclib/functions/string/strncpy.c')
-rw-r--r-- | src/pdclib/functions/string/strncpy.c | 56 |
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 |