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    The following form allows you to view linux man pages.

    Command:

    system

    
    
    

    SYNOPSIS

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

    DESCRIPTION

           system()  executes a command specified in command by calling /bin/sh -c
           command, and returns after the command has been completed.  During exe-
           cution  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(2)  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 command 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

           C89, C99, POSIX.1-2001.
    
    
    

    NOTES

           If  the  _XOPEN_SOURCE  feature test macro is defined (before including
           any header files), then the macros described in wait(2) (WEXITSTATUS(),
           etc.) are made available when including <stdlib.h>.
    
           As  mentioned, system() ignores SIGINT and SIGQUIT.  This may make pro-
           grams that call it from a loop uninterruptible, unless they  take  care
           themselves to check the exit status of the child.  E.g.
    
               while (something) {
                   int ret = system("foo");
    
                   if (WIFSIGNALED(ret) &&
                       (WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))
                           break;
               }
    
           Do  not  use  system()  from a program with set-user-ID or set-group-ID
           privileges, because strange values for some environment variables might
           be  used  to subvert system integrity.  Use the exec(3) family of func-
           tions instead, but not execlp(3) or execvp(3).  system() will  not,  in
           fact,  work  properly  from  programs  with set-user-ID or set-group-ID
           privileges on systems on which /bin/sh is bash version 2, since bash  2
           drops  privileges  on startup.  (Debian uses a modified bash which does
           not do this when invoked as sh.)
    
    
                                      2010-09-10                         SYSTEM(3)
    
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