How can I pipe multiple arguments into a unix command?

Question

I couldn't find anything similar hence posting the question.

Say I have set of commands which provides an output

First set which produces an output

cat xyx.txt | awk '{.........}' | sed 's/.../' | cut -d....   

Second set which produces an output

cat abc.txt | awk '{.........}' | cut -d ... | sed 's/...../'

I want the output of these as the 2 parameters to the "join" command. I know I can redirect these two a file and then use the join command with the files as the arguments.

Basically, can the whole thing be done in a single line.... something like

[first set of commands] > join -1 1 -2 1 < [second set of commands] 

Answer 1

If you are using bash, which is the default shell in many Linux distributions, the expression:

join <([first set of commands]) <([second set of commands])

is valid.

So

join <(cat xyx.txt | awk '{.........}' | sed 's/.../' | cut -d....) <(cat abc.txt | awk '{.........}' | cut -d ... | sed 's/...../')

should make it.

Basic example

$ cat a
1 hello
2 bye
3 ciao
$ cat b
1 hello 123
2 bye 456
3 adios 789
$ cut -d' ' -f1,2 b | awk '{print $1, 2, $2}'
1 2 hello
2 2 bye
3 2 adios
$ join <(cut -d' ' -f1,2 b | awk '{print $1, 2, $2}') a
1 2 hello hello
2 2 bye bye
3 2 adios ciao