return common fields in two files

Question

I have two files, should compare 1st column of file1 with 1st column of file2 and the resultant file should be file2

For example:

Resultant file should look something like this:

apple:fruit
tomato: vegetable
potato: vegetable

any ideas on this would be appreciated

Thanks

score 3 · Accepted Answer · answered Sep 30 '10 at 01:17

3

without the need to sort (less process creation)

$ awk -F":" 'FNR==NR{f[$0];next}($1 in f)' file file2
apple:fruit
tomato: vegetable
potato: vegetable

answered Sep 30 '10 at 01:17

ghostdog74

score 1 · Answer 2 · answered Sep 29 '10 at 14:47

1

In Bash, ksh, zsh:

join -t: <(sort file1) <(sort file2)

In other shells you will need to presort your files.

answered Sep 29 '10 at 14:47

Dennis Williamson

score 0 · Answer 3 · answered Sep 29 '10 at 14:41

0

grep "$(cat file1.txt)" file2.txt

answered Sep 29 '10 at 14:41

Alberto Zaccagni

1

`grep -f file1.txt file2.txt` – Dennis Williamson Sep 29 '10 at 14:49
@Shruti: what shell are you using? I did that in bash 4.1.5 and it worked. – Alberto Zaccagni Sep 29 '10 at 15:07
i'm using C shell I have tried it in bash too, i'm getting the same error – Shruti Sep 29 '10 at 15:31
@Shruti: Alberto's version won't work in csh, but the version in my comment should. You can also try this variation on Alberto's version: `grep "\`cat file1.txt\`" file2.txt`. It would be really weird if you're getting that error in Bash. – Dennis Williamson Sep 29 '10 at 15:52
using grep may not be suitable since grep finds the whole line for the pattern. – ghostdog74 Sep 30 '10 at 01:19

3 Answers3