STRNSTR(9) | Kernel Developer's Manual | STRNSTR(9)

# NAME

`strnstr` — locate a substring in a string

# SYNOPSIS

`#include <lib/libkern/libkern.h>`

char *
`strnstr`(const char *big, const char *little, size_t len);

# DESCRIPTION

The `strnstr`() function locates the first occurrence of the null-terminated string little in the string big, where not more than len characters are searched. Characters that appear after a ‘`\0`’ character are not searched.

# 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 `NULL`, because only the first 4 characters of largestring are searched:

    const char *largestring = "Foo Bar Baz";
    const char *smallstring = "Bar";
    char *ptr;

    ptr = strnstr(largestring, smallstring, 4);

# SEE ALSO

memchr(9)

December 21, 2023 | Debian