Bug#721040: better error message when STDIN is closed

[jidanni at jidanni.org]

Package: libjson-xs-perl
Version: 2.340-1
Severity: wishlist
File: /usr/bin/json_xs

Can you kindly print out a better message if one does

$ json_xs file.json < /dev/null
malformed JSON string, neither array, object, number, string or atom, at
character offset 0 (before "(end of string)") at /usr/bin/json_xs line
177, <STDIN> line 1.

That would prevent hours of head scratching.

Yes the user is supposed to do
$ json_xs < file.json

But if he forgets the <, and STDIN in closed, e.g., emacs M-x compile,
then he will go on the wild goose chase trying to figure out what went wrong.