Other Ways To Do It (mostly not one-liners) can be found at the thread "How do I remove blank lines from text files?".
Hmmm... personally, I like Ovid's example below better than mine. It *does* seem more directly recognizable.
perl -i.bak -ne 'print if /\S/' file.txt
Seems a bit more intuitive to me :)
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This snippet removes all non-empty lines containing
only whitespace, but I don't think that's particularly
intuitive behaviour. If I want to remove all "blank"
lines from a file, I probably want:
and if I want to get rid of all the lines with
"useless" whitespace, I probably want to collapse them
to empty lines:
perl -i.bak -ne 's/^\s+$//;print' file.txt
Update: Changed first one-liner
to Ovid's for readability.
-- Chip Salzenberg, Free-Floating Agent of Chaos
The moon would crash into the Earth
The moon would breakup at the Roche limit
The wire would turn the Earth into a giant electromagnet
The Earth would turn into a giant yo-yo.
The moon would orbit every ~24 hours, significantly changing the lunar calendar
The centripetal force would rip out the Earth's core
All man-made satellites would be destroyed, causing great havoc
Moon landings would become significantly easier
The rope or wire would break, no matter how strong it was
The Vulcans would show up for First Contact causing yet another revision to the timeline
The Galactic Police would snip the rope and put the Earth on probation
Some idiot would get terrible, terrible, rope burn
We finally get those golf balls back
Results (672 votes),