Linux / Unix Command: system

Command Library

NAME

system - execute a shell command  

SYNOPSIS

#include <stdlib.h>

int system(const char *string);

 

DESCRIPTION

system() executes a command specified in string by calling /bin/sh -c string, and returns after the command has been completed. During execution of the command, SIGCHLD will be blocked, and SIGINT and SIGQUIT will be ignored.  

RETURN VALUE

The value returned is -1 on error (e.g. fork failed), and the return status of the command otherwise. This latter return status is in the format specified in wait(2). Thus, the exit code of the command will be WEXITSTATUS(status). In case /bin/sh could not be executed, the exit status will be that of a command that does exit(127).

If the value of string is NULL, system() returns nonzero if the shell is available, and zero if not.

system() does not affect the wait status of any other children.  

CONFORMING TO

ANSI C, POSIX.2, BSD 4.3  

SEE ALSO

sh(1), signal(2), wait(2), exec(3)

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Important: Use the man command (% man) to see how a command is used on your particular computer.

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