Wikipedia:Reference desk/Archives/Computing/2018 April 21

Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

April 21

Adobe Reaper help, Windows.

I've been receiving .PDF files of images where they blank out certain parts, like with a black square or rectangle.

How do you remove those?

When I 1st open the file, I see the image in it's entirety for a split second, and then the blank covering cover up.

I read in a newspaper there was a trick to remove them. :/

Thanks. 67.175.224.138 (talk) 03:37, 21 April 2018 (UTC).

You can look here and here. Ruslik_Zero 08:35, 21 April 2018 (UTC)

zip

I'm on Ubuntu and I'm trying to use zip to zip up these two files:

/home/user/target/a
/home/user/target/b

such that I end up with a zip file in /home/user/ containing:

target/a
target/b

One limitation is that I'm only given the absolute path of the input files, and I would prefer to keep using the absolute input paths to keep things clean. (I'm invoking zip from a script and not from a shell)

So far I've tried two approaches:

zip -r /home/user/result.zip /home/user/target

produces the following zip file, which is highly undesirable due to the excessive paths:

/home/user/target/a
/home/user/target/b

The second approach uses the -j flag to drop the paths:

zip -j -r /home/user/result.zip /home/user/target

But this creates a Tarbomb unfortunately, with the zip looking like this:

a
b

What's a good solution?

I'm open to using other compression utilities as well, as long as it's able to produce a zip file. Mũeller (talk) 13:31, 21 April 2018 (UTC)

Just drop /home/user:

  cd /home/user
  zip -r result.zip target/

--Wrongfilter (talk) 14:28, 21 April 2018 (UTC)

Thanks for the response. Yes, that would be the solution if I'm running the command in a shell. But I'm invoking zip from another program, so unfortunately I'm forced to supply absolute paths for everything. Here's the Python that I'm invoking zip with:

      process = subprocess.Popen( ["zip", "-r", "-j", filename + ".zip", filename] )

Of course I could have Python spawn a shell, have the shell navigate to /home/user/, then invoke "zip -r result.zip target". That would work, but I'd prefer to keep the shell out of it to keep things simple. Mũeller (talk) 23:53, 21 April 2018 (UTC)

If you're willing to use tar then try the following:

         tar cvf result.tar -C /home/user target/

--Wrongfilter (talk) 06:40, 22 April 2018 (UTC)

You don't need the shell to set a process's "current working directory". CWDs are a process thing managed by the OS on a per-process basis, not a shell thing. This says you can pass a CWD to Popen which I guess is equivalent to doing cd in a shell. 92.230.39.123 (talk) 06:43, 22 April 2018 (UTC)

Passing in the correct CWD solved the problem. Thank you very much for the help, you two. It's much appreciated. Mũeller (talk) 09:10, 22 April 2018 (UTC)

Similarly, if it was more convenient for the rest of the script, you could also choose to set the script's own CWD before starting the subprocess. I don't do Python, but in either Perl or C you'd do chdir("/home/user"); (and, of course, check whether it succeeded). --69.159.62.113 (talk) 20:50, 22 April 2018 (UTC)