How to redirect output of wget as input to unzip?

Question

I have to download a file from this link. The file download is a zip file which I will have to unzip in the current folder.

Normally, I would download it first, then run the unzip command.

$ wget http://www.vim.org/scripts/download_script.php?src_id=11834 -O temp.zip
$ unzip temp.zip

But in this way, I need to execute two commands, wait for the completion of first one to execute the next one, also, I must know the name of the file temp.zip to give it to unzip.

Is it possible to redirect output of wget to unzip? Something like

$ unzip < `wget http://www.vim.org/scripts/download_script.php?src_id=11834`

But it didn't work.

bash: wget http://www.vim.org/scripts/download_script.php?src_id=11834 -O temp.zip: ambiguous redirect

Also, wget got executed twice, and downloaded the file twice.

Thanks

Answer 1

You have to download your files to a temp file, because (quoting the unzip man page):

Archives read from standard input are not yet supported, except with funzip (and then only the first member of the archive can be extracted).

Just bring the commands together:

wget http://www.vim.org/scripts/download_script.php?src_id=11834 -O temp.zip; unzip temp.zip; rm temp.zip

But in order to make it more flexible you should probably put it into a script so you save some typing and in order to make sure you don't accidentally overwrite something you could use the tempfile command to create a safe filename for your temp file:

#!/bin/bash
TMPFILE=`tempfile`
PWD=`pwd`
wget "$1" -O $TMPFILE
unzip -d $PWD $TMPFILE
rm $TMPFILE

Answer 2

I don't think you even want to bother piping wget's output into unzip.

From the wikipedia "ZIP (file format)" article:

A ZIP file is identified by the presence of a central directory located at the end of the file.

wget has to completely finish the download before unzip can do any work, so they run sequentially, not interwoven as one might think.

Answer 3

This thread seems to have a solution. Haven't tried it myself though.

http://serverfault.com/questions/26474/unzipping-files-that-are-flying-in-through-a-pipe