I wouldn't even bother using Perl for this.

In the *nix world...

Agreed, but it's not like using perl for this is so bad (esp. for the poor M$ users who don't know/have the unix tools):

perl -e "print sort <>" file.txt
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But -- curious discovery -- depending on the file content, this can produce somewhat different output from the unix "sort file.txt": unix sort puts empty lines first, whereas perl's sort puts them between the lines that start with tab and the ones that start with space or other characters ("\x0a" and "\x0d\x0a" come after "\x09" and before "\x20"). That is, in its simplest form, the perl version takes line termination characters into account for sorting, but unix sort does not. Doing a proper emulation of unix sort with perl takes a bit more work. So far, this is the "best" I can do (it does work -- it's just a tad ugly):

perl -e "print sort {chomp($x=$a); chomp($y=$b); $x cmp $y} <>" file.t
+xt
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(I'm not sure, but I think it would work using double-quotes in the standard M$ shell, whereas a unix shell (e.g. bash for windows) needs single quotes.)