function
<cstring>

strstr

const char * strstr ( const char * str1, const char * str2 );
      char * strstr (       char * str1, const char * str2 );
Locate substring
Returns a pointer to the first occurrence of str2 in str1, or a null pointer if str2 is not part of str1.

The matching process does not include the terminating null-characters, but it stops there.

Parameters

str1
C string to be scanned.
str2
C string containing the sequence of characters to match.

Return Value

A pointer to the first occurrence in str1 of the entire sequence of characters specified in str2, or a null pointer if the sequence is not present in str1.

Portability

In C, this function is only declared as:

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

instead of the two overloaded versions provided in C++.

Example

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

int main ()
{
  char str[] ="This is a simple string";
  char * pch;
  pch = strstr (str,"simple");
  if (pch != NULL)
    strncpy (pch,"sample",6);
  puts (str);
  return 0;
}

This example searches for the "simple" substring in str and replaces that word for "sample".

Output:

This is a sample string

See also

strspn
Get span of character set in string (function )
strpbrk
Locate characters in string (function )
strchr
Locate first occurrence of character in string (function )