CODEWITHSUNDEEP
bashshellssh
chs
chs

Reputation: 652

IO redirection of string-assembled command

I'm writing a bash script that is intended to execute some command, and depending on some flag, this command should be either executed locally or remotely. This command's output should be redirected to some file, and this file should be on the box that executes the command, that is, on the remote box if the command is executed remotely.

I'm trying things like

#!/bin/bash

REMOTE=1
function f
{
        CMD="$@"
        if [ "${REMOTE}" == "1" ]
        then
                ssh some_host "$CMD" 
        else
                $CMD 
        fi
}

# This executes "echo huhu" remotely and redirects the output into "out" on the remote box.
REMOTE=1 f echo huhu \> out

# This executes "echo haha > out" remotely (without redirection).
REMOTE=0 f echo haha \> out

When I don't escape the > sign, any output of f is redirected to "out" on the local box, of course.

How could I avoid this behavior?

Upvotes: 2

Views: 544

Answers (2)

l0b0
l0b0

Reputation: 58778

Don't use eval; use arrays instead. And a solution for the SSH command.

Upvotes: 1

don_jones
don_jones

Reputation: 852

Write eval $CMD instead of $CMD. When $CMD is expanded the interpretation of redirection has already happened and redirections operations will simply passed as ordinary arguments.

Upvotes: 1

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