第一章

while (<>) {
chomp;
print join ("\t",(split /:/)[0,2,1,5]),"\n";
}



[root@june3 perl]# cat a.txt 
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
[root@june3 perl]# perl 1.pl a.txt
root  0 x /root
bin 1 x /bin
daemon  2 x /sbin
adm 3 x /var/ad


#!/usr/bin/perl
##调用外部命令,输出结果一行行存入数组
@lines = `perldoc -u -f atan2`;
foreach (@lines){
 print "1-------$_\n";
 s/\w<([^>]+)>/\U$1/g; 
 print "2---------$_\n";
}