1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" 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. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" $OpenBSD: system.3,v 1.8 2000/10/06 04:17:51 aaron Exp $ 37.\" 38.Dd June 29, 1991 39.Dt SYSTEM 3 40.Os 41.Sh NAME 42.Nm system 43.Nd pass a command to the shell 44.Sh SYNOPSIS 45.Fd #include <stdlib.h> 46.Ft int 47.Fn system "const char *string" 48.Sh DESCRIPTION 49The 50.Fn system 51function hands the argument 52.Fa string 53to the command interpreter 54.Xr sh 1 . 55The calling process waits for the shell to finish executing the command, 56ignoring 57.Dv SIGINT 58and 59.Dv SIGQUIT , 60and blocking 61.Dv SIGCHLD . 62.Pp 63If 64.Fa string 65is 66.Dv NULL , 67.Fn system 68will return non-zero. 69Otherwise, 70.Fn system 71returns the termination status of the shell in the format specified by 72.Xr waitpid 2 . 73.Sh RETURN VALUES 74If a child process cannot be created, or the termination status of 75the shell cannot be obtained, 76.Fn system 77returns \-1 and sets 78.Va errno 79to indicate the error. 80If execution of the shell fails, 81.Fn system 82returns the termination status for a program that terminates with a call of 83.Fn exit 127 . 84.Sh SEE ALSO 85.Xr sh 1 , 86.Xr execve 2 , 87.Xr waitpid 2 , 88.Xr popen 3 89.Sh STANDARDS 90The 91.Fn system 92function conforms to 93.St -ansiC 94and 95.St -p1003.2-92 . 96.Sh CAVEATS 97Never supply the 98.Fn system 99function with a command containing any part of an unsanitized user-supplied 100string. 101Shell meta-characters present will be honored by the 102.Xr sh 1 103command interpreter. 104