CODEWITHSUNDEEP
bashawksedcut
TW93
TW93

Reputation: 139

How to delete a line if the letter after nth space matches a criteria?

I have a large text file with the data looking something like below:

ATOM 3515 CA GLY C 43 1.094 36.439 24.619 1.00 44.14 C

How would I delete a line, depending on whether the Character after the 4th space is a 'C'? I've seen a way to do it with cut like

cut -f1,4 -d' '

That removes everything from beyond the match.

Is there a way to do that for the whole line? I can see a few ways to do it in other ways, but I'd like to do it specifically off the 4th space, that way I can be definite (or more so) it's not going to parse out the wrong bits somewhere in the depths of the file.

Upvotes: 1

Views: 83

Answers (1)

anubhava
anubhava

Reputation: 785611

How would I delete a line, depending on whether the Character after the 4th space is a 'C'

You can use awk for this:

awk '$5 !~ /^C/' file
  • $5 is field # 5, i.e. field after 4th space
  • /^C/ is a check to assert that 5th field starts with C

You can get same output using substr function as well:

awk 'substr($5, 1, 1) != "C"' file

Upvotes: 3

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