strcasestr (3)

STRSTR(3) Linux Programmer's Manual STRSTR(3) NAME strstr, strcasestr - locate a substring SYNOPSIS #include <string.h> char *strstr(const char *haystack, const char *needle); #define _GNU_SOURCE #include <string.h> char *strcasestr(const char *haystack, const char *needle); DESCRIPTION The strstr() function finds the first occurrence of the substring nee- dle in the string haystack. The terminating '\0' characters are not compared. The strcasestr() function is like strstr(3), but ignores the case of both arguments. RETURN VALUE These functions return a pointer to the beginning of the substring, or NULL if the substring is not found. CONFORMING TO The strstr() function conforms to C89 and C99. The strcasestr() func- tion is a non-standard extension. BUGS Early versions of Linux libc (like 4.5.26) would not allow an empty needle argument for strstr(). Later versions (like 4.6.27) work cor- rectly, and return haystack when needle is empty. SEE ALSO index(3), memchr(3), rindex(3), strchr(3), strcasecmp(3), strpbrk(3), strsep(3), strspn(3), strtok(3), wcsstr(3), feature_test_macros(7) GNU 2005-04-05 STRSTR(3)