returns 0 when file/stdin is empty with -i

[AladW]

% touch foo
% aria2c -i foo
No files to download.
% echo $?
0

Compare to:

aria2 
zsh: correct 'aria2' to 'aria2c' [nyae]? y
Specify at least one URL.
Usage: aria2c [OPTIONS] [URI | MAGNET | TORRENT_FILE | METALINK_FILE]...
See 'aria2c -h'.
% echo $?
1

According to EXIT STATUS in aria2c(1), 0 means If all downloads were successful. You could argue that if there are no downloads to succeed, that then downloads are in fact successful; however this is a roundabout. I would suggest e.g. 3, If a resource was not found.

See also this discussion for wget (which unfortunately decided against a non-zero exit code):

http://www.mail-archive.com/wget@sunsite.dk/msg10655.html

[tatsuhiro-t]

I tend to leave exist status code as is. aria2 has relatively long history, so changing zero status code to nonzero may break existing third party code, and we'd like to avoid that.

[AladW]

Well, I don't have a suggestion to fit both cases. Thanks for considering.