1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek and the American National Standards Committee X3, 6.\" on Information Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.Dd April 3, 2022 33.Dt STRCMP 3 34.Os 35.Sh NAME 36.Nm strcmp , 37.Nm strncmp 38.Nd compare strings 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In string.h 43.Ft int 44.Fn strcmp "const char *s1" "const char *s2" 45.Ft int 46.Fn strncmp "const char *s1" "const char *s2" "size_t len" 47.Sh DESCRIPTION 48The 49.Fn strcmp 50and 51.Fn strncmp 52functions 53lexicographically compare the null-terminated strings 54.Fa s1 55and 56.Fa s2 . 57.Pp 58The 59.Fn strncmp 60function 61compares not more than 62.Fa len 63characters. 64Because 65.Fn strncmp 66is designed for comparing strings rather than binary data, 67characters that appear after a 68.Ql \e0 69character are not compared. 70.Sh RETURN VALUES 71The 72.Fn strcmp 73and 74.Fn strncmp 75functions return an integer greater than, equal to, or less than 0, according 76as the string 77.Fa s1 78is greater than, equal to, or less than the string 79.Fa s2 . 80The comparison is done using unsigned characters, so that 81.Ql \e200 82is greater than 83.Ql \e0 . 84.Sh SEE ALSO 85.Xr bcmp 3 , 86.Xr memcmp 3 , 87.Xr strcasecmp 3 , 88.Xr strcoll 3 , 89.Xr strxfrm 3 , 90.Xr wcscmp 3 91.Sh STANDARDS 92The 93.Fn strcmp 94and 95.Fn strncmp 96functions 97conform to 98.St -isoC . 99.Sh HISTORY 100The 101.Fn strcmp 102function first appeared in the Programmer's Workbench (PWB/UNIX) 103and was ported to 104.At v7 ; 105.Fn strncmp 106first appeared in 107.At v7 . 108