if that's what the OP means by "stdin or command line",

Seems it was.

you could also use -p instead of -n:

You could, but I wouldn't as it is less flexible than -n.

If you want to omit some lines from the output, you can't do that if you are also using -l

Assuming I was talking about the general case, how is -p less flexible? And how does -l matter?

perl -nle "print bar($_) unless foo($_)"
[download]

perl -ple "next if foo($_); $_=bar($_)"
[download]

With -p, whilst you can conditionally undef $_ to avoid it being printed; if you are also using -l, you will get unwanted blank lines:

C:\test>type junk.txt
1
2
3
4
5

C:\test>perl -nle"$_ & 1 and print" junk.txt
1
3
5

C:\test>perl -ple"$_ & 1 or undef $_ and next" junk.txt
1

3

5
[download]

And in fact the next in your example serves no purpose:

C:\test>perl -ple"$_ & 1 or undef $_" junk.txt
1

3

5
[download]

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

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perl -ple "next" still prints every line, so, yes, -p is less flexible based on your fine examples.

If you want to omit some lines from the output, you can't do that if you are also using -l

My first reaction to that is that the final -l was supposed to be a -p. That would certainly make sense to me, but I can't say for sure that it is what was intended.

- tye