helos1/libc/strncat.c
2021-10-10 14:11:45 +08:00

65 lines
1.2 KiB
C

/* strncat( 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 * strncat( char * s1, const char * s2, size_t n )
{
char * rc = s1;
while ( *s1 )
{
++s1;
}
while ( n && ( *s1++ = *s2++ ) )
{
--n;
}
if ( n == 0 )
{
*s1 = '\0';
}
return rc;
}
#endif
#ifdef TEST
#include "_PDCLIB_test.h"
int main( void )
{
char s[] = "xx\0xxxxxx";
TESTCASE( strncat( s, abcde, 10 ) == s );
TESTCASE( s[2] == 'a' );
TESTCASE( s[6] == 'e' );
TESTCASE( s[7] == '\0' );
TESTCASE( s[8] == 'x' );
s[0] = '\0';
TESTCASE( strncat( s, abcdx, 10 ) == s );
TESTCASE( s[4] == 'x' );
TESTCASE( s[5] == '\0' );
TESTCASE( strncat( s, "\0", 10 ) == s );
TESTCASE( s[5] == '\0' );
TESTCASE( s[6] == 'e' );
TESTCASE( strncat( s, abcde, 0 ) == s );
TESTCASE( s[5] == '\0' );
TESTCASE( s[6] == 'e' );
TESTCASE( strncat( s, abcde, 3 ) == s );
TESTCASE( s[5] == 'a' );
TESTCASE( s[7] == 'c' );
TESTCASE( s[8] == '\0' );
return TEST_RESULTS;
}
#endif