How to take command arguments from a file, one per line?

Question

Say I have a file of filenames like this:

requests.log
responses.log
resources used.log

and I want to view all of those files. I'd be tempted to do:

$ vi `cat /tmp/list`

but that winds up opening the files "requests.log", "responses.log", "resources", and "used.log" which is not what I want.

I tried

$ cat /tmp/list | xargs -L 99 vi

but that results in the error message "Warning: input not from a terminal"

I've tried editing the file and quoting each of the individual lines, but that was no help either.

Is there a way to do this short of writing some sort of front-end script?

Adding on: this is on MacOS; the xargs command has no "-a" option. — Edward Falk, May 05 '21 at 00:23
That worked, but I was hoping for something simple enough to remember. — Edward Falk, May 05 '21 at 00:32
To have command substitution 'wordsplit' only at newlines, do (IFS=$'\n'; vi $(cat list)). But if the lines in the file have trailing spaces, as your selfanswer implies, this will retain those spaces and the open will fail, so do (IFS=$'\n'; vi $(sed 's/ *$//' list)). On ancient shells you may need IFS='<actual newline here>' which looks ugly but works. — dave_thompson_085, May 05 '21 at 06:05
Thanks; good answer. My lines don't have trailing spaces; the rsplit() is to remove the trailing newlines. — Edward Falk, May 07 '21 at 17:29
Also see How to edit a list of generated files whose names contain spaces — Chris Davies, May 07 '21 at 18:30

Edward Falk · Answer 1 · 2021-05-07T17:47:37.120

Here's what I wound up writing. It works, but it's kind of a non-answer since I was hoping to do this without writing a front end.

#!/usr/bin/env python3
usage = """
Read arguments from a file, one per line, then execute the given
command.
usage:      lineargs <filename> <cmd> [args]
"""
import os
import sys
argfilename = sys.argv[1]        # Get arguments from this file, one per line
cmd = sys.argv[2:]               # The command and additional arguments
args = open(argfilename, "r").read().splitlines()
cmd.extend(args)
os.execvp(cmd[0], cmd)

I didn't bother with error checking, etc. This is just a one-off script.

How to take command arguments from a file, one per line?

1 Answers1