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in reply to Re^4: How to write a program to read stdin or command line?
in thread How to write a program to read stdin or command line?

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]
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