Comments on Tim, the Enchanter: How to escape arguments in bash

I was about to use your trick but some coworkers p...

2011-11-11T00:55:20.427-08:00

I was about to use your trick but some coworkers pointed out that there's a more elegant way to escape a string in bash, namely:

function escape() {
return printf '%q' "$@"
}

then you can just

ssh user@host "$(escape $COMMAND $ARGS)"

http://mywiki.wooledge.org/BashFAQ/096

2009-11-13T00:06:28.130-08:00

http://mywiki.wooledge.org/BashFAQ/096

Hello Tim, be careful, your script works for 9 ar...

2009-11-09T17:34:15.782-08:00

Hello Tim,

be careful, your script works for 9 arguments at most. To surpass this restriction, try this change:

COMMAND="$1"; shift;
ARGS=""
for (( i = 1; i <= $# ; i++ )); do
eval ARG=\${$i}
ARGS="$ARGS $(echo -n "$ARG" | awk 'BEGIN{RS=""} {gsub("[^\\\n]", "\\\\&");gsub("\\\n", "$'"'"'\\n'"'"'");print}')"
done
ssh user@host "$COMMAND" "$ARGS"

That's weird, for me a simple \" seems to...

2009-10-27T01:04:51.055-07:00

That's weird, for me a simple \" seems to work:

$ ssh me@server grep "1 2" somefile

does the right thing.

From Jeff Snyder (relayed via email because his co...

2009-03-09T08:53:00.000-07:00

From Jeff Snyder (relayed via email because his company blocks blogger.com)

Hi Tim,

I found myself trying to pass arguments verbatim through ssh verbatim today and came across your blog :-)
I'd have left this as a comment, but my company web proxy blocks blogger.com, so email it is.

Anyway.. I also was somewhat irritated that bash doesn't provide a builtin for it, you really shouldn't need to resort to awk magic to get something like this to work. But your solution was the best I found from a quick googling

I tested a few things with it and thought it was bulletproof at first, but unfotunately it chokes on newlines and ssh ends up executing everything after a newline as a separate command on the remote host

Here's what I've ended up with:

COMMAND="$1"; shift;
ARGS=""
for (( i = 1; i <= $# ; i++ )); do
eval ARG=\$$i
ARGS="$ARGS $(echo -n "$ARG" | awk 'BEGIN{RS=""} {gsub("[^\\\n]", "\\\\&");gsub("\\\n", "$'"'"'\\n'"'"'");print}')"
done
ssh user@host "$COMMAND" "$ARGS"

.. not very pretty.

Have you found anything better since you blogged about it?