NAME

system − issue a shell command

SYNOPSIS

#include <stdlib.h>

int system (const char ∗string);

DESCRIPTION

system causes the string to be given to the shell [see sh(1)] as input, as if the string had been typed as a command at a terminal.  The current process waits until the shell has completed, then returns the exit status of the shell in the format specified by waitpid(2). 

If string is a NULL pointer, system checks if /sbin/sh exists and is executable.  If /sbin/sh is available, system returns non-zero; otherwise it returns zero. 

system fails if one or more of the following are true:

EAGAIN The system-imposed limit on the total number of processes under execution by a single user would be exceeded. 

EINTR system was interrupted by a signal. 

ENOMEM The new process requires more memory than is allowed by the system-imposed maximum MAXMEM. 

SEE ALSO

sh(1), exec(2), waitpid(2). 

DIAGNOSTICS

system forks to create a child process that in turn execs /sbin/sh in order to execute string. If the fork or exec fails, system returns −1 and sets errno. 

  —  C Development Set