Use C to implement process monitoring. If a process exits, restart

# Include <stdio. h>
# Include <stdlib. h>
# Include <string. h>
# Include <fcntl. h>
# Include <sys/types. h>
# Include <sys/STAT. h>
# Include <Linux/types. h>
# Include <sys/Wait. H>
# Include <errno. h>
# Include <unistd. h>

// Programs to be monitored
# Define p1
"Hello1"
# Define p2
"Hello2"
# Define p3
"Hello3"
# Define path
"."

/*****************************/
Int is_run (char * Name );
Void killall_hello (void );
/*****************************/

// 1 is returned for running, 0 is returned for not running
Int is_run (char * name)
{
Int ret =-1;
Char Buf [256] = {'\ 0 '};
Snprintf (BUF, sizeof (BUF), "pidof % S>/dev/null", name );
Ret = System (BUF );
If (! Wexitstatus (RET) {// # include <sys/Wait. H>
// Printf ("% s is running! \ N ", name );
Return 1;
}
Else {
// Printf ("% s is not running! \ N ", name );

Return 0;
}
}
Void killall_hello (void)
{

Char Buf [128] = {'\ 0 '};
Snprintf (BUF, sizeof (BUF), "killall % s", P1 );
System (BUF );
Snprintf (BUF, sizeof (BUF), "killall % s", P2 );
System (BUF );
Snprintf (BUF, sizeof (BUF), "killall % s", P3 );
System (BUF );

}

Int main (INT argc, char ** argv)
{
Int p1_ret =-1;
Int p2_ret =-1;
Int p3_ret =-1;
Char Buf [128];
Bzero (BUF, sizeof (BUF ));

While (1 ){

P1_ret = is_run (P1 );
P2_ret = is_run (P2 );
P3_ret = is_run (P3 );

If (! (P1_ret & p2_ret & p3_ret ))
{
Killall_hello ();
Printf ("Rerun hello3 \ n ");
Snprintf (BUF, sizeof (BUF), "% S/% S &", path, P3 );
System (BUF );

// Print log information
System ("date> W. log ");
If (! P1_ret ){
Snprintf (BUF, sizeof (BUF), "Echo % s not run, killall, run % S> W. log", P1, P3 );
System (BUF );
}
Else if (! P2_ret ){
Snprintf (BUF, sizeof (BUF), "Echo % s not run, killall, run % S> W. log", P2, P3 );
System (BUF );
}
Else if (! P3_ret ){
Snprintf (BUF, sizeof (BUF), "Echo % s not run, killall, run % S> W. log", P3, P3 );
System (BUF );
}
}
Sleep (5 );
}
Exit (0 );
}