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Re: [Help-bash] pass command to script
From: |
Warlich, Christof |
Subject: |
Re: [Help-bash] pass command to script |
Date: |
Fri, 26 Apr 2019 14:48:59 +0000 |
Chet Ramey wrote:
> Keywords are reserved words like `for' and `case' that introduce or
> are part of compound commands. Builtins are, well, builtin commands.
> The `time' reserved word just indicates that the following command
> should be timed, which is performed internally. That's how bash can
> time pipelines and compound commands.
Ok, this explains why it's so "well behaving" when some arbitrary command
is being timed.
> > But what I am really interested in is you guys (and girls! 😊) view on
> > whether it would be desirable (and implementable with affordable effort)
> > to add some form of a nestable quoting mechanism (e.g. something like
> > $[...]) to bash for the reasons I tried to point out in my previous post.
> The $'...' form of quoting comes pretty close, but anything can fail when you
> expand the words and arbitrary number of times.
Yes, I know (i.e. I just found out today 😉) that $'...' comes pretty close. And
as
much as I can see, it even allows an arbitrary depth of nesting as long as no
ordinary single quotes are used, e.g.:
$ bash -c $'echo "hi"'
hi
$ bash -c $'bash -c $\'echo "hi"\''
hi
$ bash -c $'bash -c $\'bash -c $\\\'echo "hi"\\\'\''
hi
But as can be seen from these examples, every additional quoting layer that's
being wrapped around requires the command string _being_ wrapped to be
modified by adding appropriate escaping.
Now let's assume we had some nestable quoting mechanism similar to the
already suggested $[...]. Then, escaping would not be necessary at all, right?:
$ bash -c $[echo "hi"]
hi
$ bash -c $[bash -c $[echo "hi"]]
hi
$ bash -c $[bash -c $[bash -c $[echo "hi"]]]
hi
Passing _such_ a command line to a script would merely require to wrap this
command with another $[...] without the need to modify anything _inside_
that command line!
Doesn't that look rather appealing?
- Re: [Help-bash] pass command to script, (continued)
- [Help-bash] pass command to script, Warlich, Christof, 2019/04/26
- Re: [Help-bash] pass command to script, Warlich, Christof, 2019/04/26
- Re: [Help-bash] pass command to script, Greg Wooledge, 2019/04/26
- Re: [Help-bash] pass command to script, Chet Ramey, 2019/04/26
- Re: [Help-bash] pass command to script, Warlich, Christof, 2019/04/26
- Re: [Help-bash] pass command to script, Chet Ramey, 2019/04/26
- Re: [Help-bash] pass command to script,
Warlich, Christof <=
- Re: [Help-bash] pass command to script, Greg Wooledge, 2019/04/26
- Re: [Help-bash] pass command to script, Christof Warlich, 2019/04/26
- Re: [Help-bash] pass command to script, Chet Ramey, 2019/04/26
- Re: [Help-bash] pass command to script, Warlich, Christof, 2019/04/26
- Re: [Help-bash] pass command to script, Chet Ramey, 2019/04/26
- Re: [Help-bash] pass command to script, Christof Warlich, 2019/04/26
- Re: [Help-bash] pass command to script, Chet Ramey, 2019/04/26