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- /* Simple implementation of strstr for systems without it.
- This function is in the public domain. */
- /*
- @deftypefn Supplemental char* strstr (const char *@var{string}, const char *@var{sub})
- This function searches for the substring @var{sub} in the string
- @var{string}, not including the terminating null characters. A pointer
- to the first occurrence of @var{sub} is returned, or @code{NULL} if the
- substring is absent. If @var{sub} points to a string with zero
- length, the function returns @var{string}.
- @end deftypefn
- */
- #include <stddef.h>
- extern int memcmp (const void *, const void *, size_t);
- extern size_t strlen (const char *);
- char *
- strstr (const char *s1, const char *s2)
- {
- const size_t len = strlen (s2);
- while (*s1)
- {
- if (!memcmp (s1, s2, len))
- return (char *)s1;
- ++s1;
- }
- return (0);
- }
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