"joining" an array with tabs (default is space)

"joining" an array with tabs (default is space)

[Webb Sprague]

Hi all,

If I set IFS='\t', it works great with read -A LINE.  However I want
to join the output using '\t' instead of spaces-- is there a simple
way to do that?  I can write a for loop, or maybe recycle print -f
"\t%s", or maybe use columns in the print, but I was hoping for a
super graceful (ie typical zsh) approach.

Thanks!

Re: "joining" an array with tabs (default is space)

[Peter Stephenson]

On Tue, 9 Dec 2008 11:27:38 -0800
"Webb Sprague" <webb.sprague@gmail.com> wrote:
> If I set IFS='\t', it works great with read -A LINE.  However I want
> to join the output using '\t' instead of spaces-- is there a simple
> way to do that?  I can write a for loop, or maybe recycle print -f
> "\t%s", or maybe use columns in the print, but I was hoping for a
> super graceful (ie typical zsh) approach.

  ${(pj.\t.)array}

It's a bit cryptic, but the documentation is there under "Parameter
Expansion Flags" in the zshexpn manual.

-- 
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/

Re: "joining" an array with tabs (default is space)

[Webb Sprague]

>  ${(pj.\t.)array}

Awesome

> It's a bit cryptic, but the documentation is there under "Parameter
> Expansion Flags" in the zshexpn manual.

I believe it.  As I a very, very new zsh user, I feel a little less
bad, but I will try harder next time.

Tx
W

Re: "joining" an array with tabs (default is space)

[Stephane Chazelas]

On Tue, Dec 09, 2008 at 11:27:38AM -0800, Webb Sprague wrote:
> Hi all,
> 
> If I set IFS='\t', it works great with read -A LINE.  However I want
> to join the output using '\t' instead of spaces-- is there a simple
> way to do that?  I can write a for loop, or maybe recycle print -f
> "\t%s", or maybe use columns in the print, but I was hoping for a
> super graceful (ie typical zsh) approach.
[...]

Try IFS=$'\t'
Then "${var[*]}" will be joined with spaces. It's the same in
every Bourne-like shell but the Bourne shell (and earlier Almquist
shells)

$ IFS=$'\t'
$ set a b
$ echo "$*" | cat -t
a^Ib
$ a=(a b)
$ echo "${a[*]}" | cat -t
a^Ib

Actually, with zsh (and zsh only) $array is the same as
${array[*]}, so:

$ echo "$a" | cat -t
a^Ib


-- 
Stéphane

Re: "joining" an array with tabs (default is space)

[Stephane Chazelas]

On Wed, Dec 10, 2008 at 07:00:30AM +0000, Stephane Chazelas wrote:
> On Tue, Dec 09, 2008 at 11:27:38AM -0800, Webb Sprague wrote:
> > Hi all,
> > 
> > If I set IFS='\t', it works great with read -A LINE.  However I want
> > to join the output using '\t' instead of spaces-- is there a simple
> > way to do that?  I can write a for loop, or maybe recycle print -f
> > "\t%s", or maybe use columns in the print, but I was hoping for a
> > super graceful (ie typical zsh) approach.
> [...]
> 
> Try IFS=$'\t'
> Then "${var[*]}" will be joined with spaces.
[...]

Oops, brain is going slow in winter....


I meant "with tabs" above not spaces obviously.

"$*" (quotes are important) joins the elements of the array with
the first character of $IFS (or sticks them together if $IFS is
empty).

> It's the same in
> every Bourne-like shell but the Bourne shell (and earlier Almquist
> shells)
> 
> $ IFS=$'\t'
> $ set a b
> $ echo "$*" | cat -t
> a^Ib
> $ a=(a b)
> $ echo "${a[*]}" | cat -t
> a^Ib
> 
> Actually, with zsh (and zsh only) $array is the same as
> ${array[*]}, so:
> 
> $ echo "$a" | cat -t
> a^Ib
[...]

-- 
Stephane