Construct a process tree similar to Figure $3\mathrm{.}8.$ To obtain process infor$$ mation for the UNIX or Linux system, use the command ps $-$ael.

#include

#include

#include

int main$()$

$\{$

pid$\_$t pid;

$/*$ fork a child process $*/$ pid $=$ fork$()$;

if $($pid $<0)\{/*$ error occurred $*/$ fprintf$($stderr$,$ "Fork Failed"$)$; return $1$ ;

$\}$

else if $($pid $==0)\{/*$ child process $*/$ execlpC$/$bin$/1$ s$","$Is$".$NULL$)$; printf$("$LINE J$")$;

$\}$

else $\{/*$ parent process $*/$

$/*$ parent will wait for the child to complete $*/$ wait$($NULL$)$;

printf$("$Child Complete"$)$;

$\}$

return $0$ ;

$\}$