Trace the program below, and identify the values of the pids at

lines A$,$ B$,$ C$,$ and D$.($Assume that the actual pids of the parent and child are $2600$ and $2603,$

respectively. Also assume that fork will always succeed.$)$

#include

#include

#include

int main$()\{$

pid$\_$t pid, pid$1$;

$/*$ fork a child process $*/$

pid $=$ fork$()$;

if $($pid $<0)\{/*$ error occurred $*/$

fprintf$($stderr$,$ "Fork Failed"$)$;

return $1$;

$\}$

else if $($pid $==0)\{$

pid$1=$ getpid$()$;

printf$("$child: pid $=\%$d$",$ pid$)$; $/*$A$*/$

printf$("$child: pid$1=\%$d$",$ pid$1)$; $/*$B$*/$

$\}$

else $\{$

pid$1=$ getpid$()$;

printf$("$parent: pid $-\%$d$",$ pid$)$; $/*$C$*/$

printf$("$parent: pid$1=\%$d$",$ pidl$)$; $/*$D$*/$

wait$($NULL$)$;

$\}$

return $0$;

$\}$