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).

       allbox;  lb  lb  lb  l  l  l.   Interface Attribute Value  T{  strstr()
       T}   Thread  safety    MT-Safe  T{ strcasestr() T}   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 4.16 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                               2017-09-15                         STRSTR(3)