NAME

strcmp, strncmp — compare strings

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <string.h>

int
strcmp(const char *s1, const char *s2);

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

DESCRIPTION

The strcmp() and strncmp() functions lexicographically compare the null-terminated strings s1 and s2.

The strncmp() function compares not more than len characters. Because strncmp() is designed for comparing strings rather than binary data, characters that appear after a ‘\0’ character are not compared.

RETURN VALUES

The strcmp() and strncmp() functions return an integer greater than, equal to, or less than 0, according as the string s1 is greater than, equal to, or less than the string s2. The comparison is done using unsigned characters, so that ‘\200’ is greater than ‘\0’.

SEE ALSO

bcmp(3), memcmp(3), strcasecmp(3), strcoll(3), strxfrm(3), wcscmp(3)

STANDARDS

The strcmp() and strncmp() functions conform to ISO/IEC 9899:1990 (“ISO C90”).

HISTORY

The strcmp() function first appeared in the Programmer's Workbench (PWB/UNIX) and was ported to Version 7 AT&T UNIX; strncmp() first appeared in Version 7 AT&T UNIX.