Re: regex string ">(...)" in [[ ]] command recognize as process substitution

[Chet Ramey]

On 10/31/22 1:31 AM, Hyunho Cho wrote:

> # this is an error
> # [[ ]] command recognizes ">(.*)" as process substitution.
> bash$ [[ $val =~ ((.*)<[^>]*>(.*)) ]] && echo yes      # Error !
> bash$ .*: command not found

Yes, process substitution is one of the word expansions the pattern
undergoes (all words between [[ and ]] undergo the same set of word
expansions).

> ################  The Second problem  #################
>
> This only happens in the terminal.
>
> # 1. intentionally makes an error by removing escape "\>" to ">"
> bash$ [[ $val =~ (.*)\ \<[^\>]*>\ (.*) ]] && echo yes
> bash: syntax error in conditional expression: unexpected token `>'
>
> # 2. fixed the error with \> escape, but the error continues
> bash$ [[ $val =~ (.*)\ \<[^\>]*\>\ (.*) ]] && echo yes
> bash: syntax error near unexpected token `$val'

This has already been fixed, the result of

https://savannah.gnu.org/support/index.php?110745


> # 3. On the second try, the error goes away.
> bash$ [[ $val =~ (.*)\ \<[^\>]*\>\ (.*) ]] && echo yes
> yes
>
> ################  The third problem  #################
>
> This also happens only in the terminal.
> but very unexpectedly happens

I can't reproduce this using bash-5.2.2.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/