Re: Man page on conditional expressions: =~ missing?

[Marco Ippolito]

On 27/08/2020 11:02, Francois Tonneau wrote:
> Hello,
>
> I have a comment/suggestion/question about the man page of GNU bash
> 5.0.16(1) on Debian.
>
> The section on:
>
> Compound Commands
> [[ expression ]], where expression is a conditional expression
>
> mentions correctly that "an additional binary operator, =~, is available
> ..."
>
> Yet later, in the section on:
>
> CONDITIONAL EXPRESSIONS,
> where "expressions are formed from the following unary or binary primaries"
> ..., I could not see any mention of =~ (whereas == and != are mentioned).
>
> For the sake of completeness, shouldn't the =~ operator mentioned in the
> later list?  A conditional expression with the regex operator does seem to
> work in current bash (for example,  [[ foo =~ ^foo$ && bar == bar ]] &&
> echo ok).

Man page:

> Conditional expressions are used by the [[ compound command and the 
test and [ builtin commands

Note:

One can't use =~ with [

If you do:

bash: [: =~: binary operator expected