Perlシェルコマンド呼び出しのメソッド概要

[root@AX3sp2 ~]# cat aa.pl
#! /usr/bin/perl -w
$file = "wt.pl";
system("ls -l wt.pl");
$result = system "ls -l $file";
print "$result \n"; # Output the exit status of the command
system "date";

[root@AX3sp2 ~]# perl aa.pl
-rwxr-xr-x 1 root root 126 12-16 15:12 wt.pl
-rwxr-xr-x 1 root root 126 12-16 15:12 wt.pl
0
Thu, Dec 16, 2010 15:58:34 CST     

[root@AX3sp2 ~]# cat bb.pl
#! /usr/bin/perl
print `date`;
print "this is test \n";

[root@AX3sp2 ~]# perl bb.pl
Thu, Dec 16, 2010 15:51:59 CST
This is test

[root@AX3sp2 ~]# cat cc.pl
#! /usr/bin/perl
exec ("echo this is test");
print "good bye ! \n"; #This sentence will not be output

[root@AX3sp2 ~]# perl cc.pl
This is test