Re: [Help-bash] Hook for `set -v`

[Greg Wooledge]

On Wed, Jun 10, 2015 at 05:17:37PM -0500, Peng Yu wrote:
> The foo example that you showed below print the highlight commands all
> at once.

INCORRECT!

You fail to understand.

I chose that example ON PURPOSE.  It is a clear example of why set -v
is rubbish.

If I had chosen an example like this:

#!/bin/bash -v
command one
command two
command three

Then it would have APPEARED to do what you want, and you would
have gained a FALSE SENSE OF ACCOMPLISHMENT by using a tool that
only works in the simplest, most stupid, most degenerate, most
not-in-need-of-a-fancy-debugging-tool cases.

> I want the commands and their output be interleaved as what
> happens with `set -v`.

You are confused about what set -v does.

set -v prints lines AS THEY ARE READ by the shell's PARSER.

It does NOT print COMMANDS that are EXECUTED.  That is what set -x does.

set -v is totally different.

set -v is almost completely USELESS in real life.

That's why nobody uses it.

That's why it's dramatically under-documented.

That's why nobody CARES about it.

And stop using that fucking backtick markup to indicate "this is a
shell command".  It's confusing as all hell, because backticks are
also valid syntax within a bash command.