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
   needle 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
   substring, 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

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   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/.

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