[SOLVED] bash or zsh: how to pass multiple inputs to interactive piped parameters?

Issue

I have 3 different files that I want to compare

words_freq words_freq_deduped words_freq_alpha

For each file, I run a command like so, which I iterate on constantly to compare the results.

For example, I would do this:

$ cat words_freq | grep -v '[soe]'
$ cat words_freq_deduped | grep -v '[soe]'
$ cat words_freq_alpha | grep -v '[soe]'

and then review the results, and then do it again, with an additional filter

$ cat words_freq | grep -v '[soe]' | grep a | grep r | head -n20
a

$ cat words_freq_deduped | grep -v '[soe]' | grep a | grep r | head -n20
b

$ cat words_freq_alpha | grep -v '[soe]' | grep a | grep r | head -n20
c

This continues on until I've analyzed my data.

I would like to write a script that could take the piped portions, and pass it to each of these files, as I iterate on the grep/head portions of the command.

e.g. The following would dump the results of running the 3 commands above AND also compare the 3 results, and dump additional calculations on them

$ myScript | grep -v '[soe]' | grep a | grep r | head -n20
the letters were in all 3 runs, and it took 5 seconds
a
b
c

How can I do this using bash/python or zsh for the myScript part?

EDIT: After asking the question, it occurred to me that I could use eval to do it, like so, which I've added as an answer as well

The following approach allows me to process multiple files by using eval, which I know is frowned upon - any other suggestions are greatly appreciated!

$ myScript "grep -v '[soe]' | grep a | grep r | head -n20"

myScript

#!/usr/bin/env bash
function doIt(){
  FILE=$1
  CMD="cat $1 | $2"
  echo processing file "$FILE"
  eval "$CMD"
  echo
}

doIt words_freq "$@" 
doIt words_freq_deduped "$@" 
doIt words_freq_alpha "$@"

Solution

The following approach allows me to process multiple files by using eval, which I know is frowned upon - any other suggestions are greatly appreciated!

$ myScript "grep -v '[soe]' | grep a | grep r | head -n20"

myScript

#!/usr/bin/env bash
function doIt(){
  FILE=$1
  CMD="cat $1 | $2"
  echo processing file "$FILE"
  eval "$CMD"
  echo
}

doIt words_freq "$@" 
doIt words_freq_deduped "$@" 
doIt words_freq_alpha "$@"

Answered By - Brad Parks

Answer Checked By - Senaida (WPSolving Volunteer)