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

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

[bolega]

Basically, I have spent a few hours experimenting and searching on the
comp.unix.shell

how to break a command with several switches into more than one line
AND to be able to put some comment on each line.

#!/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.

Bolega

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

[Oleksandr Gavenko]

On 13.01.2011 23:18, bolega wrote:
> Basically, I have spent a few hours experimenting and searching on the
> comp.unix.shell
>
> how to break a command with several switches into more than one line
> AND to be able to put some comment on each line.
>
> #!/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.
>
This is offtopic for this list.

But seems POSIX shell do not support inline comments.

You can use such trick (: is NOP command, but `` invoke shell, so 
consume CPU resource):

   $ printarg -x `: this opt allow x` \
   -y `: this opt allow y` \
   -z `: this opt allow z`
"printarg"
"-x"
"-y"
"-z"

I put comments before command like (example from Makefile):

# /O1  creates small code
# /Oi-  disable generate intrinsic functions (to save exe size)
# /Oy  omit frame pointer
# /Gm-  disable minimal rebuild
OPTIM_CFLAGS =  /O1 /Oi- /Oy /Gm-

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

[Berthold Höllmann]

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bolega <gnuist006@gmail.com> writes:

> Basically, I have spent a few hours experimenting and searching on the
> comp.unix.shell
>
> how to break a command with several switches into more than one line
> AND to be able to put some comment on each line.
>
> #!/bin/bash -xv
>
> command       \ # comment1
>          -sw1 \ # comment2
>          -sw2 \ # comment3
>          arguments

How about 

-----------
#!/bin/bash -xv

COMMAND=command       # comment1
COMMAND=$COMMAND -sw1 \ # comment2
COMMAND=$COMMAND -sw2 \ # comment3
COMMAND=$COMMAND arguments

$COMMAND
---------
?

Regards 
Berthold 
> One ought to be able to comment every single switch if desired for
> whatever reason.
>
> Bolega
>
>

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

[David W. Hodgins]

On Thu, 13 Jan 2011 16:18:31 -0500, bolega <gnuist006@gmail.com> wrote:

> how to break a command with several switches into more than one line
> AND to be able to put some comment on each line.
> command       \ # comment1
>          -sw1 \ # comment2

Not what you want to hear, but that will not work.  With the above,
the backslash is being used to escape the following space, rather
then a newline, as is required to continue the line.  Even if it
were to work that way, would the next line be considered a continuation
of the command, or of the comment?

Your stuck with

command       \
          -sw1
# comment1
# comment2

Regards, Dave Hodgins

-- 
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use in usenet. Feel free to use it yourself.)

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

[suvayu ali]

On Thu, Jan 13, 2011 at 1:18 PM, bolega <gnuist006@gmail.com> wrote:
> Basically, I have spent a few hours experimenting and searching on the
> comp.unix.shell
>
> how to break a command with several switches into more than one line
> AND to be able to put some comment on each line.
>
> #!/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.
>

I don't think you can, but why post a shell question on the GNU emacs
users list?

> Bolega
>
>
>



-- 
Suvayu

Open source is the future. It sets us free.

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

[Pascal J. Bourguignon]

bolega <gnuist006@gmail.com> writes:

> Basically, I have spent a few hours experimenting and searching on the
> comp.unix.shell
>
> how to break a command with several switches into more than one line
> AND to be able to put some comment on each line.
>
> #!/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.

Rewrite your script in clisp:

#!/usr/bin/clisp 

(ext:shell (format nil "~{~A ~}"
              "command" ; comment1
              "-sw1"    ; comment2
              "-sw2"    ; comment3
              arguments))


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

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

[Stefan Monnier]

> #!/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

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

[bolega]

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 ?

Bolega

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

[Pascal J. Bourguignon]

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 {}.