| 
STRSTR(3) | 
Library Functions Manual | 
STRSTR(3) | 
NAME
 strstr, strcasestr — 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);
 
DESCRIPTION
 The 
strstr() function locates the first occurrence of the nul-terminated string 
little in the nul-terminated string 
big.
The strcasestr() function is similar to strstr(), but ignores the case of both strings.
 
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);
 
STANDARDS
 The strstr() function conforms to ISO/IEC 9899:1990 (“ISO C90”).