Name
system
Synopsis
Executes a shell command
#include <stdlib.h> intsystem
( const char *s
);
The system()
function
passes a command line addressed by the pointer argument
s
to an operating system shell. If
s
is a null pointer, the function returns
true
(a nonzero value) if a
command processor is available to handle shell commands, and 0 or
false
if not.
How the system executes a command, and what value the system()
function returns, are left up to
the given implementation. The command may terminate the program that
calls system()
, or have
unspecified effects on its further behavior.
Example
if ( system( NULL ))system
( "echo \"Shell: $SHELL; process ID: $$\"");
else
printf( "No command processor available.\n" );
This example is not portable, but on certain systems it can produce output like this:
Shell: /usr/local/bin/bash; process ID: 21349
See Also
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