STRSTR(3)              FreeBSD Library Functions Manual              STRSTR(3)

NAME
     strstr, strcasestr, strnstr - locate a substring in a string

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <string.h>

     char *
     strstr(const char *big, const char *little);

     char *
     strcasestr(const char *big, const char *little);

     char *
     strnstr(const char *big, const char *little, size_t len);

     #include <string.h>
     #include <xlocale.h>

     char *
     strcasestr_l(const char *big, const char *little, locale_t loc);

DESCRIPTION
     The strstr() function locates the first occurrence of the null-terminated
     string little in the null-terminated string big.

     The strcasestr() function is similar to strstr(), but ignores the case of
     both strings.

     The strcasestr_l() function does the same as strcasestr() but takes an
     explicit locale rather than using the current locale.

     The strnstr() function locates the first occurrence of the null-
     terminated string little in the string big, where not more than len
     characters are searched.  Characters that appear after a `\0' character
     are not searched.  Since the strnstr() function is a FreeBSD specific
     API, it should only be used when portability is not a concern.

RETURN VALUES
     If little is an empty string, big is returned; if little occurs nowhere
     in big, NULL is returned; otherwise a pointer to the first character of
     the first occurrence of little is returned.

EXAMPLES
     The following sets the pointer ptr to the "Bar Baz" portion of
     largestring:

           const char *largestring = "Foo Bar Baz";
           const char *smallstring = "Bar";
           char *ptr;

           ptr = strstr(largestring, smallstring);

     The following sets the pointer ptr to NULL, because only the first 4
     characters of largestring are searched:

           const char *largestring = "Foo Bar Baz";
           const char *smallstring = "Bar";
           char *ptr;

           ptr = strnstr(largestring, smallstring, 4);

SEE ALSO
     memchr(3), memmem(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3),
     strsep(3), strspn(3), strtok(3), wcsstr(3)

STANDARDS
     The strstr() function conforms to ISO/IEC 9899:1990 ("ISO C90").

FreeBSD 13.1-RELEASE-p6        October 11, 2001        FreeBSD 13.1-RELEASE-p6