strncmp man page

Prolog

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

strncmp — compare part of two strings

Synopsis

#include <string.h>

int strncmp(const char *s1, const char *s2, size_t n);

Description

The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1‐2008 defers to the ISO C standard.

The strncmp() function shall compare not more than n bytes (bytes that follow a NUL character are not compared) from the array pointed to by s1 to the array pointed to by s2.

The sign of a non-zero return value is determined by the sign of the difference between the values of the first pair of bytes (both interpreted as type unsigned char) that differ in the strings being compared.

Return Value

Upon successful completion, strncmp() shall return an integer greater than, equal to, or less than 0, if the possibly null-terminated array pointed to by s1 is greater than, equal to, or less than the possibly null-terminated array pointed to by s2 respectively.

Errors

No errors are defined.

The following sections are informative.

See Also

strcmp()

The Base Definitions volume of POSIX.1‐2008, <string.h>

Info

2013 IEEE/The Open Group POSIX Programmer's Manual