Re: GURU NEEDED : break a command into several lines and comment each line

["Pascal J. Bourguignon" <pjb@informatimago.com>]

bolega <gnuist006@gmail.com> writes:

> On Jan 13, 7:12 pm, Stefan Monnier <monn...@iro.umontreal.ca> wrote:
>> > #!/bin/bash -xv
>> > command       \ # comment1
>> >          -sw1 \ # comment2
>> >          -sw2 \ # comment3
>> >          arguments
>> > One ought to be able to comment every single switch if desired for
>> > whatever reason.
>>
>> Thanks for the riddle.  Here's a solution:
>>
>>   command        $(: # comment1
>>   )        -sw1  $(: # comment2
>>   )        -sw2  $(: # comment3
>>   )        arguments
>>
>> -- Stefan
>
> thanks to all four of you who replied and solved this problem to a
> large extent, building on each other's ideas.
>
> I would have done it by the first method of concatenating or pipes
> into a sed which replaced end by the next and # can be placed after
> pipes. the string then fed into a bash.
>
> Stefan, whats the purpose of the colon ? it works without colon also.
> Is it subshell or some environment import ? like the colon which can
> substitute the #!/bin/bash on the top ?

The colon is a built-in command equivalent to true.


The syntax specified for $( ... ) (in man bash) is:

       $(command)

so a command is expected.  The shortest command doing nothing is :.

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
A bad day in () is better than a good day in {}.