I found a question about, how to remove lines longer then 2048 chars: How to delete line if longer than XY?Q: But how can I remove lines shorter then 4 chars? So remove lines that has 1 or 2 or 3 length in a file. UPDATE: Thanks for the many GOOD answers, but I can only mark one as OK
How to remove lines shorter than XY?
text processing;sed
You could use sed.  The following would remove lines that are 3 characters long or smaller:sed -r '/^.{,3}$/d' filenameIn order to save the changes to the file in-place, supply the -i option.If your version of sed doesn't support extended RE syntax, then you could write the same in BRE:sed '/^.\{,3\}$/d' filenamewhich would work with all sed variants.You could also use awk:awk 'length($0)>3' filenameUsing perl:perl -lne 'length()>3 && print' filename