第十四章：进程管理

1)
use warnings;
chdir "/" or die "Can't chdir to root directory: $!";
exec "ls", "-l" or die "Can't exec ls: $!";
#my $info = `ls -l /`;
#print $info;

2)
use warnings;
open STDOUT, ">ls.out" or die "Can't write to ls.out: $!";
open STDERR, ">ls.err" or die "Can't write to ls.err: $!";
chdir "/" or die "Can't chdir to root directory: $!";
exec "ls", "-l" or die "Can't exec ls: $!";
#my $info = `ls -l / > ls.out 2>&1`;

3)
use warnings;
my $date = `date`;
my $day = substr $date, 0, 3;
if ($day eq "Sun" or $day eq "Sat"){ #if(`date` =~ /^(Sat|Sun)/)
 print "go play!\n"; 
}else{
 print "get to work!\n"; 
}