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How to delete lines in a file with sed which match a certain pattern and are longer or shorter than certain length

I am able to delete lines with certain patterns and shorter sed '/^.\{,20\}$/d' -i FILE or longer sed '/^.\{25\}..*/d' -i FILE than certain length separately, but how do I unite pattern and length in sed?

Lines containing A should be between 20 and 25 characters

Lines containing B should be between 10 and 15 characters

Lines containing C should be between 3 and 8 characters

All other lines should be deleted from the file

1234567890 A 1234567890
12345 A 12345
1 A 1
1234567890 B 1234567890
12345 B 12345
1 B 1
1234567890 C 1234567890
12345 C 12345
1 C 1

So that the output should look like this

1234567890 A 1234567890
12345 B 12345
1 C 1
Solution

  • This is how you can do it with sed:

    $ sed -ne '/A/ s/^\(.\{20,25\}\)$/\1/p; /B/ s/^\(.\{10,15\}\)$/\1/p; /C/ s/^\(.\{3,8\}\)$/\1/p;' file
1234567890 A 1234567890
12345 B 12345
1 C 1

    How does it work:

    -ne - suppress printing pattern
/A/ - look for pattern A
^\(.\{20,25\}\)$ - line with 20-25 characters
/\1/p - print pattern space