1 : #!/usr/local/bin/perl
2 :
3 : open (WOUT, "w|");
4 : $time =; 根据上下文context $time 存储 w的第一行
5 : $time =~ s/^ *//;
6 : $time =~ s/ .*//;
7 :; # skip headings line 第二行;表示跳过此行，并指针移往下一行
8 : @users =; 表示将余下的各行放入@users;
9 : close (WOUT);
10: foreach $user (@users) {
11: $user =~ s/ .*//;
12: }
13: print ("Current time: $time");
14: print ("Users logged on:\n");
15: $prevuser = "";
16: foreach $user (sort @users) {
17: if ($user ne $prevuser) {
18: print ("\t$user");
19: $prevuser = $user;
20: }
21: }
结果输出如下：
Current time: 4:25pm
Users logged on:
dave
kilroy
root
zarquon