Re: expr integer format always decimal?

[Paul Eggert]

address@hidden (Bob Proulx) writes:

> However, I can't see anywhere that expr is defined to always read
> integers as decimal values.

The current documentation says under "expr invocation"

Operands are either integers or strings.  Integers consist of one or
more decimal digits, with an optional leading @samp{-}.

So yes, they're always decimal.  (POSIX requires this.)

>   expr foo + 0
>   expr: non-numeric argument

I don't think you can't rely on this behavior in general, as an
extended version of "expr" could treat "foo" as some sort of
integer, as an extension.