On 3/26/20, George <tetsu...@scope-eye.net> wrote:
> On Thu, 2020-03-26 at 19:05 +0200, Vaidas BoQsc wrote:
> I think shells would really benefit from things like
> more powerful data structures, better facilities for passing complex data
> to, and parsing complex data from different programs, better scoping,
> better file handling, and clean-up of various language and implementation
> details that currently tend to trip people up.
I can almost hear the same thoughts going through Larry Wall's head 30+
years ago (:
> $ some_command -file1 $fd1 -file2 $fd2 {fd1}<./first_file
> {fd2}<./second_file
>
> to work as a substitute for this:
>
> $ exec {fd1}<./first_file {fd2}<./second_file # open files, store file
> descriptor numbers in parameters
> $ some_command -file1 $fd1 -file2 $fd2
> $ exec {fd1}<&- {fd2}<&- # close files
>
> That is, open the files just for the command being run (because that's how
> redirections work) and make the parameters storing the file descriptor
> numbers available before expanding parameters in the command, so you can
> pass them to the command.
Are you familiar with Bash's <(...) syntax?
Your example could be written (if I understand right):
$ some_command -file1 <(cat ./first_file) -file2 <(cat ./second_file)
Though that doesn't store the descriptors in variables.
Personally, I've found that I've grown into shell syntax over the years.
I certainly went through phases where it felt strange and clunky (and some
parts genuinely are, to be sure), but I have come to appreciate more of
the design choices and less-known features over time.
One day I may even read the entire manual page and understand it!
