std::strstr

C++

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Concepts library (C++20)

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Technical Specifications

Strings library

Null-terminated strings

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Classes

basic_string

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char_traits

Null-terminated byte strings

Functions
Character manipulation
isalnum isalpha islower isupper isdigit isxdigit isblank (C++11)	iscntrl isgraph isspace isprint ispunct tolower toupper
Conversions to numeric formats
atof atoiatolatoll (C++11) strtolstrtoll (C++11)	strtoulstrtoull (C++11) strtofstrtodstrtold (C++11)(C++11) strtoimaxstrtouimax (C++11)(C++11)
String manipulation
strcpy
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strcat
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String examination
strlen strcmp strncmp strcoll strchr strrchr	strspn strcspn strpbrk strstr strtok
Memory manipulation
memchr
memcmp
memset
memcpy
memmove
Miscellaneous
strerror

Defined in header <cstring>
const char* strstr( const char* str, const char* target );
char* strstr( char* str, const char* target );

Finds the first occurrence of the byte string target in the byte string pointed to by str. The terminating null characters are not compared.

Parameters

str	-	pointer to the null-terminated byte string to examine
target	-	pointer to the null-terminated byte string to search for

Return value

Pointer to the first character of the found substring in str, or NULL if no such character is found. If target points to an empty string, str is returned.

Example

Run this code

#include <iostream>
#include <cstring>

int main()
{
    const char *str = "Try not. Do, or do not. There is no try.";
    const char *target = "not";
    const char *result = str;

    while ((result = std::strstr(result, target)) != NULL) {
        std::cout << "Found '" << target 
                  << "' starting at '" << result << "'\n";

        // Increment result, otherwise we'll find target at the same location
        ++result;
    }   
}

Output:

Found 'not' starting at 'not. Do, or do not. There is no try.'
Found 'not' starting at 'not. There is no try.'

See also

find	find characters in the string (public member function of std::basic_string)
wcsstr	finds the first occurrence of a wide string within another wide string (function)
strchr	finds the first occurrence of a character (function)
strrchr	finds the last occurrence of a character (function)