Word splitting in parameter expansion

Word splitting in parameter expansion

[Björn Lindström]

I've got this in my .zshrc:

    man() {
        screen -h 0 -t "man $@" man $@
    }

This works fine as long as I only supply the function with one argument,
such as "man access", but when I do "man 5 access", it interprets
"5 access" as one argument (even though that is not what I meant ;-).

I have read through the zshexpn man page, and tried quite a few
variations on this, but can't seem to figure it out. Can anyone help me
out?

-- 
Björn Lindström <bkhl@privat.utfors.se>
Home page: http://hem.fyristorg.com/bkhl/
Blog: http://bkhl.livejournal.com/
Elektrubadur demo: http://hem.fyristorg.com/bkhl/elektrubadur/

Re: Word splitting in parameter expansion

[Peter Stephenson]

=?iso-8859-1?Q?Bj=F6rn_Lindstr=F6m?= wrote:
> I've got this in my .zshrc:
> 
>     man() {
>         screen -h 0 -t "man $@" man $@
>     }
> 
> This works fine as long as I only supply the function with one argument,
> such as "man access", but when I do "man 5 access", it interprets
> "5 access" as one argument (even though that is not what I meant ;-).

I don't think it's doing quite what you say (although you don't see what
options you have set), but I agree it won't do what you expect...

If the arguments are `5' and `access' I would expect the words to be
divided as:

screen
-h
0
-t
man 5
access
man
5
access

(which is certainly what I get with my option settings).  The problem is
that the argument to -t is being divided into two parts.  To prevent that
you need:

man() {
    screen -h 0 -t "man $*" man $@
}

Actually, that last argument could be $* as well; if you want to
maintain zero-length arguments it needs to be "$@".

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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Re: Word splitting in parameter expansion

[Lloyd Zusman]

Peter Stephenson <pws@csr.com> writes:

> =?iso-8859-1?Q?Bj=F6rn_Lindstr=F6m?= wrote:
>> I've got this in my .zshrc:
>> 
>>     man() {
>>         screen -h 0 -t "man $@" man $@
>>     }
>> 
>> This works fine as long as I only supply the function with one argument,
>> such as "man access", but when I do "man 5 access", it interprets
>> "5 access" as one argument (even though that is not what I meant ;-).
>
> I don't think it's doing quite what you say (although you don't see what
> options you have set), but I agree it won't do what you expect...
>
> If the arguments are `5' and `access' I would expect the words to be
> divided as:
>
> screen
> -h
> 0
> -t
> man 5
> access
> man
> 5
> access

A small correction: I believe the args would actually be divided thusly:

screen
-h
0
-t
man 5 access
man
5
access

In the "man $@" portion above, the "$@" should be replaced with
"5 access".







> (which is certainly what I get with my option settings).  The problem is
> that the argument to -t is being divided into two parts.  To prevent that
> you need:
>
> man() {
>     screen -h 0 -t "man $*" man $@
> }
>
> Actually, that last argument could be $* as well; if you want to
> maintain zero-length arguments it needs to be "$@".
>
> -- 
> Peter Stephenson <pws@csr.com>                  Software Engineer
> CSR Ltd., Science Park, Milton Road,
> Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070
>
>
> **********************************************************************
> The information transmitted is intended only for the person or
> entity to which it is addressed and may contain confidential 
> and/or privileged material. 
> Any review, retransmission, dissemination or other use of, or
> taking of any action in reliance upon, this information by 
> persons or entities other than the intended recipient is 
> prohibited.  
> If you received this in error, please contact the sender and 
> delete the material from any computer.
> **********************************************************************

-- 
 Lloyd Zusman
 ljz@asfast.com

Re: Word splitting in parameter expansion

[Peter Stephenson]

Lloyd Zusman wrote:
> A small correction: I believe the args would actually be divided thusly:

No, that's the whole point of the message.  The $@ in quotes institutes
word breaks between words of the arguments array.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


**********************************************************************
The information transmitted is intended only for the person or
entity to which it is addressed and may contain confidential 
and/or privileged material. 
Any review, retransmission, dissemination or other use of, or
taking of any action in reliance upon, this information by 
persons or entities other than the intended recipient is 
prohibited.  
If you received this in error, please contact the sender and 
delete the material from any computer.
**********************************************************************

Re: Word splitting in parameter expansion

[Lloyd Zusman]

Peter Stephenson <pws@csr.com> writes:

> Lloyd Zusman wrote:
>> A small correction: I believe the args would actually be divided thusly:
>
> No, that's the whole point of the message.  The $@ in quotes institutes
> word breaks between words of the arguments array.

Ah yes ... not enough sleep and too much coffee.  Sorry.


-- 
 Lloyd Zusman
 ljz@asfast.com