Removing a character at specific position in a column

Syeda Sumayya · 10-13-2015, 12:53 AM

Hi,

I have a file like this (about 8 columns in total, this being the 2nd column)

Code:

gi_49482297_ref_YP_039521.1_
gi_49482297_ref_YP_039521.1_
gi_49482315_ref_YP_039539.1_
gi_49482315_ref_YP_039539.1_

I want to remove the _ at the end of the line.
And at later stages I would want to replace the _ with another character perhaps.

how can I do it using awk or sed?

Any help would be highly appreciated.

chrism01 · 10-13-2015, 01:02 AM

Welcome to LQ

Here's something that does only that, just as a ptr towards creating your own soln

Code:

echo 'gi_49482315_ref_YP_039539.1_'|sed  -E 's/_$//'
gi_49482315_ref_YP_039539.1

If eg the cols are separated by exactly one space, then you could use the 'cut' cmd to pull this out for processing.

Really we'd like to see

a) some whole recs so we can see the actual issue
b) what code have you tried so far - we prefer to help you solve this, rather than just handout solns

grail · 10-13-2015, 01:55 AM

As chrism01 has said, this really is not enough information, but based on the loose details, you could use awk like so:

Code:

awk 'sub(/_$/,"",$2)' file