shell/awk -- print certain fields of a row if a column exists in another file

Question

I have a universe file /tmp/universe.txt

aaa
bbb
ccc

I have another csv file, and I only wants to print a certain fields of a row of this csv file if the first field exists in /tmp/universe.txt

for example for this file

aaa,1
ddd,3
ccc,2

I want to print

aaa,1
ccc,2

How do I achieve it? I could write a python/perl script, but i suspect there are more elegant solution in awk/bash etc.

What have you attempted so far in order to achieve it? – arco444 Nov 13 '15 at 15:42 — arco444, Nov 13 '15 at 15:42

score 3 · Accepted Answer · answered Nov 13 '15 at 15:50

3

This could be as simple as:

grep -f universe.txt file

But this solution assumes that you list complete words which can't match partially in universe.txt. E.g.: listing aa or 1 would also match aaa,1.

For complete matches you need:

grep -f <(sed 's/.*/^\0,/' universe.txt) file

assuming there aren't any special characters in universe.txt.

answered Nov 13 '15 at 15:50

Karoly Horvath

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Thanks Karoly. There are "dots" in my universe.txt, how should I escape them using your sed method? – CuriousMind Nov 13 '15 at 15:56
For a more generic solution see here: http://stackoverflow.com/questions/407523/escape-a-string-for-a-sed-replace-pattern – Karoly Horvath Nov 13 '15 at 15:57
Thanks. grep -f is awesome. more elegant than I imagined. – CuriousMind Nov 13 '15 at 15:57

shell/awk -- print certain fields of a row if a column exists in another file

1 Answers1