UNIX for Dummies Questions & Answers

I have two text files. One has two columns and looks like below:

rs# otherallele_freq
rs10399749 0
rs4030303 0
rs4030300 0
rs940550 1.000
rs13328714 0
rs11490937 0
rs6683466 0
rs12025928 1.000
rs6650104 0
rs11240781 0
rs6594028 1.000

The other one is basically a single column that looks like the following:

rs# otherallele_freq
rs10399749
rs940550
rs241979
rs13328714
rs891898021
rs12025928
rs342908

The first column of the first file and the second file match but not completely. How do I merge the text files by the first column so that I get the following output?

rs10399749 0
rs940550 1.000
rs13328714 0
rs12025928 1.000

Thank you!

Code:

join -j1 <(sort file1) <(sort file2)

What if I want to merge by a different column (say 2nd column of the 1st file and the 1st column of the 2nd file)? Thanks!

Then you should use this:

Code:

join -12 -21 <(sort file1) <(sort file2)

I've indicated column numbers in red so it will be easier to understand those options.

Code:

$ xargs < file2 | sed 's, ,|,g;s,^,egrep \",g;s,$,\" file1,g' | sh

Code:

 
$ fgrep -f two.txt first.txt
rs10399749 0
rs940550 1.000
rs13328714 0
rs12025928 1.000