On Tue, Sep 4, 2012 at 7:13 PM, Roman Rakus <rra...@redhat.com> wrote:
> Hi, > Petr, adding to cc: list, found behaviour not documented, neither in man > page nor bash ref manual: > ${par-word} will do expansion of par, and if the par is unset it is > substituted by word. It is different from ${par:-word}, where word is used > when par is unset or null. > > Is it undocumented and deprecated, like $[]? Or just undocumented? > >From man page: When not performing substring expansion, using the forms documented below, bash tests for a parameter that is unset or null. Omitting the colon results in a test only for a parameter that is unset. > > RR > >