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author | Marcus Huderle <huderlem@gmail.com> | 2017-12-27 16:22:00 -0600 |
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committer | GitHub <noreply@github.com> | 2017-12-27 16:22:00 -0600 |
commit | 6b611a3046a694d3972f2aa4df90d3ef78801217 (patch) | |
tree | 05f295c00cbbc1d5987a05da37e746fb841d4d83 /libc/string/strstr.c | |
parent | 58c860d6c48324eba66dd19540db5584d832cf58 (diff) | |
parent | d88495e3f4061a411e654c7307aa94ac8a98c94b (diff) |
Merge pull request #13 from ProjectRevoTPP/libc
add libc building to agbcc.
Diffstat (limited to 'libc/string/strstr.c')
-rw-r--r-- | libc/string/strstr.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/libc/string/strstr.c b/libc/string/strstr.c new file mode 100644 index 0000000..dddced3 --- /dev/null +++ b/libc/string/strstr.c @@ -0,0 +1,73 @@ +/* +FUNCTION + <<strstr>>---find string segment + +INDEX + strstr + +ANSI_SYNOPSIS + #include <string.h> + char *strstr(const char *<[s1]>, const char *<[s2]>); + +TRAD_SYNOPSIS + #include <string.h> + char *strstr(<[s1]>, <[s2]>) + char *<[s1]>; + char *<[s2]>; + +DESCRIPTION + Locates the first occurence in the string pointed to by <[s1]> of + the sequence of characters in the string pointed to by <[s2]> + (excluding the terminating null character). + +RETURNS + Returns a pointer to the located string segment, or a null + pointer if the string <[s2]> is not found. If <[s2]> points to + a string with zero length, the <[s1]> is returned. + +PORTABILITY +<<strstr>> is ANSI C. + +<<strstr>> requires no supporting OS subroutines. + +QUICKREF + strstr ansi pure +*/ + +#include <string.h> + +char * +_DEFUN (strstr, (searchee, lookfor), + _CONST char *searchee _AND + _CONST char *lookfor) +{ + if (*searchee == 0) + { + if (*lookfor) + return (char *) NULL; + return (char *) searchee; + } + + while (*searchee) + { + size_t i; + i = 0; + + while (1) + { + if (lookfor[i] == 0) + { + return (char *) searchee; + } + + if (lookfor[i] != searchee[i]) + { + break; + } + i++; + } + searchee++; + } + + return (char *) NULL; +} |