Join command

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1

Hi,

I am trying to join 2 files..viz

f1:
12~a1
13~a2
112~a3
1112~a4

f2:
12~fa2
13~fa2
112~fa3
1112~fa4

while I join..I just get 2 o/p..
12~a1~fa2
13~a2~fa2

while the rest doesnt appear:-(

Can any1 help me in this plss?

Thanx
Sam

2

You can use -o option to specify the fields you want to see in the output.

join -o 1.1 1.2 2.1 2.2 file1 file2

will show the first two fields for both files in one line.

Try man join.

3

You can also try the paste command.

paste file1 file2

4

The join command requires that the files be sorted in lexical sequence. Your files are sorted by numerical sequence.

$ cat f1
12~a1
13~a2
112~a3
1112~a4
$ cat f2
12~fa2
13~fa2
112~fa3
1112~fa4
$ join -t '~' f1 f2
12~a1~fa2
13~a2~fa2
$ sort f1 > s1
$ sort f2 > s2
$ join -t '~' s1 s2
1112~a4~fa4
112~a3~fa3
12~a1~fa2
13~a2~fa2

5

I've just realised that you don't have to sort the files if you use awk...

$ awk 'BEGIN{FS=OFS="~"}FNR==NR{a[$1]=$2}FNR!=NR{print $1,a[$1],$2}' f1 f2
12~a1~fa2
13~a2~fa2
112~a3~fa3
1112~a4~fa4