Linux unzip: don't prompt user

Question

I need to unzip a file in my nodejs script:

var exec = require('child_process').exec;

var execOptions = { timeout: 15000 };

exec('bash unzip.sh', execOptions, function (error) {
   ...
});

In unzip.sh I do:

set -e
unzip my_file.zip -d /var/tmp/my_dir

The destination directory has some quota limits for its size. And sometimes I got:

write error (disk full?).  Continue? (y/n)

And then after 15 sec the exec() fails with timeout (this is OK).

How can I tell unzip to do not prompt user and fail immediately, to avoid 15 sec timeouts?

I've tried unzip my_file.zip -d /var/tmp/my_dir 2> /dev/null but this does not work.

Answer 1

I did not find the option that tells unzip to switch to non-interactive mode, but I found a workaround. I know this looks ugly, but try it:

/bin/echo "n" | /usr/bin/unzip -o $zipfile -d $dir

It will send "n" as a reply to unzip's question.

Answer 2

unzip -qq $file -d $dest works like a charm.

Answer 3

I'd recommend to refer to the options that can be set with the unzip command. Therefore type man unzip or unzip --help.

Mostly the -f option forces the operation without prompting you. The -q option reduces output. A mix of these two and perhaps some other options you'll find in the reference I mentioned above can help you get the options right.

Answer 4

Another solution is to use a closed file handle as the standard in. Unzip will work as always but if it prompts for input it will automatically close.

$ ls
spacefiller  test.zip
$ unzip test.zip
Archive:  test.zip
  inflating: test.bin
test.bin:  write error (disk full?).  Continue? (y/n/^C) ^C$
$ rm test.bin
$ unzip test.zip <&-
Archive:  test.zip
  inflating: test.bin
test.bin:  write error (disk full?).  Continue? (y/n/^C)
warning:  test.bin is probably truncated
$ echo $!
24130

This solution will work for other similar problems as well.

unzip -qq test.zip

As above will work similarly with a similar exit number.