std::strstr

 

C++

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Feature test macros (C++20)

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Null-terminated byte strings

Functions
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isalnum isalpha islower isupper isdigit isxdigit	isblank (C++11) iscntrl isgraph isspace isprint ispunct
Character manipulation
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)
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strcpy strncpy strxfrm	strcat strncat
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strlen strcmp strncmp strcoll strchr strrchr	strspn strcspn strpbrk strstr strtok
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memchr memcmp memset	memcpy memmove
Miscellaneous
strerror

 

Defined in header <cstring>
const char* strstr( const char* haystack, const char* needle );
char* strstr(       char* haystack, const char* needle );

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

Parameters

haystack	-	pointer to the null-terminated byte string to examine
needle	-	pointer to the null-terminated byte string to search for

Return value

Pointer to the first character of the found substring in haystack, or a null pointer if no such character is found. If needle points to an empty string, haystack is returned.

Example

Run this code

#include <cstring>
#include <iomanip>
#include <iostream>
 
int main()
{
    const char* str = "Try not. Do, or do not. There is no try.";
    const char* target = "not";
 
    for (const char* result = str; (result = std::strstr(result, target)); ++result)
        std::cout << "Found " << std::quoted(target)
                  << " starting at (" << result - str << "): "
                  << std::quoted(result) << '\n';
}

Output:

Found "not" starting at (4): "not. Do, or do not. There is no try."
Found "not" starting at (19): "not. There is no try."

See also

find	finds the first occurrence of the given substring (public member function of std::basic_string<CharT,Traits,Allocator>)
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)
C documentation for strstr

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