如何获取执行我的 Perl 脚本的用户的姓名？

Question

I have a script that needs to know what username it is run from.

When I run it from shell, I can easily use $ENV{"USER"}, which is provided by bash.

But apparently - then the same script is run from cron, also via bash - $ENV{"USER"} is not defined.

Of course, I can:

my $username = getpwuid( $< );

But it doesn't look nice - is there any better/nicer way? It doesn't have to be system-independent, as the script is for my personal use, and will be only run on Linux.

Answer 1

尝试从几个地方获得答案，首先获胜：

my $username = $ENV{LOGNAME} || $ENV{USER} || getpwuid($<);

Answer 2

crontab sets $LOGNAME so you can use $ENV{"LOGNAME"} . $LOGNAME is also set in my environment by default (haven't looked where it gets set though) so you might be able to use only $LOGNAME instead of $USER .

Although I agree with hacker, don't know what's wrong about getpwuid .

Answer 3

Does this look prettier?

use English qw( −no_match_vars );

my $username = getpwuid $UID;

Answer 4

Sorry, why doesn't that "look nice"? That's the appropriate system call to use. If you're wanting an external program to invoke (eg something you could use from a bash script too), there are the tools /usr/bin/id and /usr/bin/whoami for use.

Answer 5

Apparently much has changed in Perl in recent years, because some of the answers given here do not work for fetching a clean version of "current username" in modern Perl.

For example, getpwuid($<) prints a whole bunch of stuff (as a list in list context, or pasted-together as a string in scalar context), not just the username, so you have to use (getpwuid($<))[0] instead if you want a clean version of the username.

Also, I'm surprised no one mentioned getlogin(), though that doesn't always work. For best chance of actually getting the username, I suggest:

my $username = getlogin() || (getpwuid($<))[0] || $ENV{LOGNAME} || $ENV{USER};