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	   /* See feature_test_macros(7) */

       #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 null bytes ('\0') are  not
       compared.

       The  strcasestr()  function  is	like strstr(), but ignores the case of
       both arguments.

RETURN VALUE
       These functions return a pointer to the beginning of the	 located  sub-
       string, or NULL if the substring is not found.

ATTRIBUTES
       For   an	  explanation	of   the  terms	 used  in  this	 section,  see
       attributes(7).

       +-------------+---------------+----------------+
       |Interface    | Attribute     | Value	      |
       +-------------+---------------+----------------+
       |strstr()     | Thread safety | MT-Safe	      |
       +-------------+---------------+----------------+
       |strcasestr() | Thread safety | MT-Safe locale |
       +-------------+---------------+----------------+
CONFORMING TO
       strstr(): POSIX.1-2001, POSIX.1-2008, C89, C99.

       The strcasestr() function is a nonstandard extension.

SEE ALSO
       index(3), memchr(3), memmem(3),	rindex(3),  strcasecmp(3),  strchr(3),
       string(3), strpbrk(3), strsep(3), strspn(3), strtok(3), wcsstr(3)

COLOPHON
       This  page  is  part of release 4.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest	  version     of     this    page,    can    be	   found    at
       https://www.kernel.org/doc/man-pages/.



GNU				  2015-08-08			     STRSTR(3)