Deleting lines from one file which are in another file

bash scripting sh
lalli picture lalli · Jan 24, 2011 · Viewed 72.2k times · Source

I have a file f1:

line1
line2
line3
line4
..
..

I want to delete all the lines which are in another file f2:

line2
line8
..
..

I tried something with cat and sed, which wasn't even close to what I intended. How can I do this?

Answer

gabuzo picture gabuzo · Jan 24, 2011

grep -v -x -f f2 f1 should do the trick.

Explanation:

  • -v to select non-matching lines
  • -x to match whole lines only
  • -f f2 to get patterns from f2

One can instead use grep -F or fgrep to match fixed strings from f2 rather than patterns (in case you want remove the lines in a "what you see if what you get" manner rather than treating the lines in f2 as regex patterns).

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