Using grep to omit values given in a text file Omit.txt 001 006 008 0016 Filetogrepfrom.txt 001 006 007 008 0016 00546 008 0031 00 0021 0016 I want to do cat filetogrepfrom.txt | grep -a 00 | grep -v {lines from omit.txt}

grep -a 00 Filetogrepfrom.txt | grep -vf omit.txt


> -f file, --file=file
>
>> Read one or more newline separated patterns from file. Empty pattern lines match every input line. Newlines are not considered part of a pattern. If file is empty, nothing is matched.

This should do what you want.

Note: `grep` can read from a file so there is no need for `cat`

Also your `grep -a 00` is unnecessary given your example as it will match all lines. Additionally it seems unlikely that you will need `-a` for a `.txt` file but I have seen stranger things.