system

Pass a command to the shell

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Contents

Interface
Description
Standards
Page Comments

Interface

#include <stdlib.h>int  system (const char *string)

Description

The system function hands the argument string to the command interpreter. The calling process waits for the shell to finish executing the command, ignoring SIGINT and SIGQUIT, and blocking SIGCHLD.

If string is a NULL pointer, system will return non-zero if the command interpreter is available, and zero if it is not.

The system function returns the exit status of the shell as returned by waitpid, or -1 if an error occurred when invoking fork or waitpid. A return value of 127 means the execution of the shell failed.

The following code displays the contents of the current directory using the DIR command.

Example:

Example - Pass a command to the shell

Workings

#include <stdlib.h>
int main ()
{
  system("dir");
  return 0;
}

Standards

The system function conforms to ISO/IEC 9899:1990 ("ISO C90") and is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.