C++ reference: cstring: strstr

strstr
char * strstr ( const char * string1, const char * string2 );

string.h

cplusplus.com

Find substring.
Scans string1 for the first occurrence of string2.
The search does not include terminating null-characters.

Parameters.

string1: Null-terminated string to search.
string2: Null-terminated string containing the substring to search for.

Return Value.
A pointer to the first occurrence of string2 in string1.
If string2 is not found in string1 the function returns NULL.

Portability.
Defined in ANSI-C.
ANSI-C++ standard specifies two different declarations for this function instead of the one included in ANSI-C:

const char * strstr ( const char * string1, const char * string2 );
      char * strstr (       char * string1, const char * string2 );

Both have the same behavior as the original declaration.

Example.

/* strstr example */
#include <stdio.h>
#include <string.h>

main ()
{
  char str[] ="This is a simple string";
  char * pch;
  pch = strstr (str,"simple");
  strncpy (pch,"sample",5);
  puts (str);
  return 0;
}

This example searches for simple substring in str and substitutes that word for sample.
Output:
This is a sample string

See also.
strcspn, strspn, strpbrk, strchr