Negative array subscript with unset

2011-03-12 Thread Chris F.A. Johnson 


  I all versions I have tried, unsetting an array element using a
  negative index fails:

$ array=( q w e r t y )
$ unset 'array[-1]'
bash: [-1]: bad array subscript


--
   Chris F.A. Johnson, http://cfajohnson.com/
   Author:
   Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)
   Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)

Re: Negative array subscript with unset

2011-03-12 Thread Dennis Williamson 
On Sat, Mar 12, 2011 at 6:21 PM, Chris F.A. Johnson
ch...@cfajohnson.com wrote:

  I all versions I have tried, unsetting an array element using a
  negative index fails:

 $ array=( q w e r t y )
 $ unset 'array[-1]'
 bash: [-1]: bad array subscript


 --
   Chris F.A. Johnson, http://cfajohnson.com/
   Author:
   Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)
   Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)



Assignments to negative indices don't work either. (Bash 4.2)

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Re: Negative array subscript with unset

2011-03-12 Thread Chet Ramey 
On 3/12/11 7:21 PM, Chris F.A. Johnson wrote:
 
   I all versions I have tried, unsetting an array element using a
   negative index fails:
 
 $ array=( q w e r t y )
 $ unset 'array[-1]'
 bash: [-1]: bad array subscript

Negative subscripts only work with ${parameter[subscript]}.  The problem
is that I put the text in the manual page describing their use in the
wrong place.  It should have gone in the paragraph describing array
references.

Negative subscripts will work in more contexts in the next version of bash.

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