Passing string with spaces to bash script and using within string concatenation

Question

I have an argument to a bash script which could be a string with spaces. How can I use this within a string concatenation such as below:

#!/usr/bin/env bash

curl -X POST -H 'Content-type: application/json' \
--data '{"text":"'$1'"}' https://hooks.slack.com/services/<rest of URL secret!>

From cmd line if I do:

$./myscript.sh oneword

It works perfectly fine. But if I pass a string with spaces:

$./myscript.sh "two words"

curl: (3) [globbing] unmatched close brace/bracket in column 5
invalid_payload%

I have tried all sorts of quoting to concatenate it correctly, but to no avail. Thanks

Don't generate JSON by hand, unless (maybe) you already know that `$1` is a valid JSON string. — chepner, Nov 04 '19 at 15:47

score 1 · Accepted Answer · answered Nov 04 '19 at 14:56

1

You need to quote $1 as well in your JSON payload:

curl -X POST -H 'Content-type: application/json' \
--data '{"text":"'"$1"'"}' https://hooks.slack.com/services/<rest of URL secret!>

answered Nov 04 '19 at 14:56

anubhava

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Even this may fail if `$1` can't safely be merged (it might contain a double quote itself). – chepner Nov 04 '19 at 15:48
If double quotes can also be passed in `$1` then OP may use: `"${1//\"/\\\"}"` – anubhava Nov 04 '19 at 15:51
1

Letting something like `jq` construct the JSON is far safer. `"$(jq -n --arg x "$1" '{text: $x}')"`. – chepner Nov 04 '19 at 15:57

Passing string with spaces to bash script and using within string concatenation

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