Cannot extract with just the extension

[dangerousNull]

This is how it should be:
(with > unar 797590\ Seven\ Lions\ -\ Summer\ Of\ The\ Occult\ \(1\).osz)

797590 Seven Lions - Summer Of The Occult (1).osz: Zip
  Seven Lions - Summer of the Occult (Alphabet) [Divine Empire of the Supernatural].osu  (54665 B)... OK.
  audio.mp3  (8174159 B)... OK.
  drum-hitclap.wav  (129500 B)... OK.
  drum-hitfinish.wav  (762982 B)... OK.
  drum-hitnormal.wav  (354434 B)... OK.
  drum-slidertick.wav  (117804 B)... OK.
  normal-hitclap3.wav  (129500 B)... OK.
  normal-hitclap4.wav  (104124 B)... OK.
  normal-hitfinish2.wav  (762982 B)... OK.
  normal-hitfinish4.wav  (762982 B)... OK.
  normal-hitfinish5.wav  (762982 B)... OK.
  normal-hitnormal2.wav  (377984 B)... OK.
  normal-hitnormal3.wav  (377984 B)... OK.
  normal-hitnormal5.wav  (377984 B)... OK.
  normal-hitwhistle3.wav  (354434 B)... OK.
  normal-hitwhistle4.wav  (354434 B)... OK.
  normal-sliderslide2.wav  (44 B)... OK.
  normal-slidertick3.wav  (44 B)... OK.
  soft-hitnormal.wav  (40664 B)... OK.
  soft-hitnormal2.wav  (40664 B)... OK.
  soft-hitwhistle.wav  (354434 B)... OK.
  superrrrrrrrrrrrrrrrrrr.png  (1398944 B)... OK.
Successfully extracted to "797590 Seven Lions - Summer Of The Occult (1)".

This is how it is when I only specify the extension:
(with > unar *.osz)

797590 Seven Lions - Summer Of The Occult (1).osz: Zip
No files extracted.

Can someone help me out?

[ssokolow]

That's pretty standard behaviour for command-line archivers. Tools like unzip and 7z behave the same way.

Note the synopsis from unar' manpage:

unar [OPTION]... ARCHIVE [FILE]...

The shell expands wildcards before unar even sees them and, if more than one thing matches *.osz, then the ones after the first one get interpreted as the [FILE] arguments which filter for which files to extract.

If you had a.osz, b.osz, and c.osz in the same folder, then unar *.osz would become unar a.osz b.osz c.osz before being fed to unar and unar would interpret that as "Extract b.osz and c.osz from inside a.osz".

The workaround is to use this instead:

for X in *.osz; do unar "$X"; done