1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)system.3 6.4 (Berkeley) 04/19/91 7.\" 8.Dd 9.Dt SYSTEM 3 10.Os 11.Sh NAME 12.Nm system 13.Nd pass a command to the shell 14.Sh SYNOPSIS 15.Fd #include <stdlib.h> 16.Ft int 17.Fn system "const char *string" 18.Sh DESCRIPTION 19The 20.Fn system 21function 22hands the argument 23.Fa string 24to the command interpreter 25.Xr sh 1 . 26The calling process waits for the shell 27to finish executing the command, 28ignoring 29.Dv SIGINT 30and 31.Dv SIGQUIT , 32and blocking 33.Dv SIGCHLD . 34.Pp 35If 36.Fa string 37is a 38.Dv NULL 39pointer, 40.Fn system 41will return non-zero if the command interpreter 42.Xr sh 1 43is available, and zero if it is not. 44.Pp 45The 46.Fn system 47function 48returns the exit status of the shell, or \-1 if the 49.Xr wait 3 50for the shell failed. 51A return value of 127 means the execution of the shell 52failed. 53.Sh SEE ALSO 54.Xr sh 1 , 55.Xr execve 2 , 56.Xr wait 2 , 57.Xr popen 3 58.Sh STANDARDS 59The 60.Fn system 61function 62conforms to 63.St -ansiC . 64