Bash script to tar – Quoting issue [duplicate]

Question

This question already has answers here:

Security implications of forgetting to quote a variable in bash/POSIX shells (3 answers)

Closed 7 years ago.

I have a script that takes filenames as positional parameters. I perform a few operations on these and then tar them. Currently my script is not working. The echo line is there for debugging purposes.

Please clarify this statement

But when I try to tar with in the script if can file the file I want to tar.

SNIPPET

while [[ $# > 0 ]]; do
 key="1ドル"
 shift
 files=$files" "\"${key}\"
 done
echo tar -cvf backup.tar $files
tar -cvf backup.tar $files

OUTPUT:

tar -cvf backup.tar "test.txt"
tar: "test.txt": Cannot stat: No such file or directory
tar: Exiting with failure status due to previous errors

I am using the double quotes around the filename (test.txt) as I want to handle files with spaces.

If I were to remove the quotes in the script (\"), it will work but then I can’t handle filenames with spaces.

Any ideas?

• B Layer: Why not just pass the file params directly to tar? tar -cvf backup.tar "$@" ?
• jesse_b: what about: files="$files \"${key}\""? Or use an array...files+=("$key") and then tar -cvf backup.tar ${files[@]}
• Scott - Слава Україні: See But what if ...?
• jesse_b: Wouldn't he need the $files variable in the tar statement unquoted though? Otherwise, wont they be treated as one argument?
• peterh: Use capital letters.

Answer 1

If you are always using all the params then just call tar like this: tar -cvf backup.tar "$@". Otherwise, if you are selecting a subset (though you don't show it) then build up the file list in an array like this:

declare -a files
while [[ $# > 0 ]]; do
 key="1ドル"
 shift
 # assume some filtering goes on here
 files+=("$key")
 done
tar -cvf backup.tar "${files[@]}"

• goldengreen: excellent this work using the array and quoting when adding to the array. Thanks a million.