Re: child_pid of background process? (not in manpage?)

[Chet Ramey]

On 8/19/13 1:52 PM, Linda Walsh wrote:
> 
> 
> Chris Down wrote:
>> On 2013-08-18 17:46, Linda Walsh wrote:
>>> I don't find the variable for the process ID of the
>>> last started background process documented in the bash manpage...
>>>
>>> Am I just missing it, or did it get left out by accident or
>>> where did it go?
>>
>> First of all, it would help if you gave your version. At least in 4.2.45,
>> it's
>> under "Special Parameters".
>>
>>> Special Parameters
>>>
>>> [...]
>>>
>>>     !      Expands to the process ID of the most recently executed
>>>            background (asynchronous) command.
> ---
> That explains it... There's -- in searching the output, I'm
> pretty sure that seeing a stray '!' in the left hand margin
> wouldn't have looked like a var.
> 
> In this case, especially for the 1 char vars, wouldn't it be
> easier to help people see them and help them search for them
> if they included the '$' before them so they wouldn't look
> like stray punctuation?  or so I could search on \$[^a-zA-Z0-0]
> and find it?

It might.  It might also result in many more people complaining that
the name of the variable is really `!', not `$!', so why am I including
the dollar sign, and only for the single-character variables?  Based on
history, the chances are 50-50.

I personally prefer the manpage format, but this is one place where the
texinfo format has clear advantages: the easy ability to add items to
and use multiple indexes.

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