Added public domain implementations of strchr and strstr.

This commit is contained in:
Dave Hylands 2014-01-12 22:34:58 -08:00
parent 34f813ee29
commit c8effff937
3 changed files with 31 additions and 0 deletions

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@ -3,6 +3,7 @@
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include <sys/types.h>
#include "nlr.h"
#include "misc.h"

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@ -17,6 +17,8 @@ int strncmp(const char *s1, const char *s2, size_t n);
char *strndup(const char *s, size_t n);
char *strcpy(char *dest, const char *src);
char *strcat(char *dest, const char *src);
char *strchr(const char *s, int c);
char *strstr(const char *haystack, const char *needle);
int printf(const char *fmt, ...);
int snprintf(char *str, size_t size, const char *fmt, ...);

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@ -108,3 +108,31 @@ char *strcat(char *dest, const char *src) {
*d = '\0';
return dest;
}
// Public Domain implementation of strchr from:
// http://en.wikibooks.org/wiki/C_Programming/Strings#The_strchr_function
char *strchr(const char *s, int c)
{
/* Scan s for the character. When this loop is finished,
s will either point to the end of the string or the
character we were looking for. */
while (*s != '\0' && *s != (char)c)
s++;
return ((*s == c) ? (char *) s : 0);
}
// Public Domain implementation of strstr from:
// http://en.wikibooks.org/wiki/C_Programming/Strings#The_strstr_function
char *strstr(const char *haystack, const char *needle)
{
size_t needlelen;
/* Check for the null needle case. */
if (*needle == '\0')
return (char *) haystack;
needlelen = strlen(needle);
for (; (haystack = strchr(haystack, *needle)) != 0; haystack++)
if (strncmp(haystack, needle, needlelen) == 0)
return (char *) haystack;
return 0;
}