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Accepted
Nilesh
Asked: 2022-06-19 06:50:15 +0800 CST

Escape space in bash variable value without quoting

  • 772

In a bash script, we can escape spaces with \ . Is there any way to do the same from code?

$ a=hello\ world
$ echo $a
hello world
$ b=${a:?}  # ? used as dummy; it will not work
$ echo $b
hello\ world

caller.bash

#!/bin/bash
name=$1
if [[ -n $name ]]; then
    where_query="--where name $name"
fi
mycommand $where_query

mycommand, an external program, we cannot modify. Dummy code added only for illustration purposes.

#!/bin/bash
for i in "${@}"
do
   echo "$i"
done

Actual

$ caller.bash "foo bar"
--where
name
foo
bar

Expected

$ caller.bash "foo bar"
--where
name
foo bar
command-line

1 Answers

  1. Best Answer

    What you are trying to do is impossible with simple string variables. You are trying to pass either three parameters or none to the "external program" mycommand. You should use bash arrays. Please try the following:

    caller.bash:

    #!/bin/bash
name=$1
if [[ -n $name ]]; then
    where_query=("--where" "name" "$name")
fi
mycommand "${where_query[@]}"

    Your scripts have also quoting errors. You should check all your scripts at https://www.shellcheck.net/ before trying to use them at all.

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