Square bracket test expressions in GRUB2's scripting language undocumented.

[João Ricardo Sares Teles de Matos]

Usage of the square brackets to evaluate conditional expressions, for example:

if [ -s $prefix/grubenv ]; then
  load_env
fi

Is seen being used in typical GRUB 2 configurations shipped with popular 
GNU/Linux distros, but I couldn't find any documentation on the subject.

The only related thing I could find was in the node 'Shell-like scripting' 
(5.2) of the manual, where the strings "[[" and "]]" are declared as reserved 
words, like in bash. But no mention of just "[" at all.

Can the documentation for the "test" command from GNU Coreutils be used safely 
for GRUB 2's "[" command?

Is this feature documented anywhere at all, outside the source?

Thank you,
João Ricardo Matos

signature.asc
Description: OpenPGP digital signature