[arch-general] bash - pathname expansion controls 'set -f' or 'set -o noglob' on broken? - Arch-general

13 Aug 2010


      Guys,

	I'm either misunderstanding how to control expansion of wildcards on the 
command line when passing the parameter containing the wildcard as a cli option 
to a script or the bash controls to allow that are broken. I want to set up a 
little script alias to search /var/abs for packages and I want the ability to 
pass either 'name' or 'name*' or '*name*' as input, but if there is anything 
matching in the current directory, expansion happens before the cli is passed to 
the script.

	Reading, I should be able to turn globbing off with either 'set -f' or 'set -o 
noglob' and then I should be able to pass the parameter contained a wildcard to 
the script without any pathname expansion. That appears broken -- or my logic is 
broken.

	From man bash 'set -f' or 'set -o noglob on' should prevent expansion:

  set [+abefhkmnptuvxBCEHPT] [+o option] [arg ...]
  <snip>
   -f      Disable pathname expansion.
  <snip>
   -o option-name
         The option-name can be one of the following:
  <snip>
         noglob  Same as -f.

EXAMPLE:

   touch pacman-foo

then use the following as your test script (tst.sh):

#!/bin/bash

myvar="$1"

printf "Search:  %s\n" $myvar

exit 0

	Now since i have a file called pacman-foo in my directory trying to pass 
'pacman*' should result in expansion before the cli is read resulting in:

00:42 nirvana:~/scr/arch/tmp> ./tst.sh pacman*
Search:  pacman-foo

	single-quoting doesn't even protect the cli?? :

00:42 nirvana:~/scr/arch/tmp> ./tst.sh 'pacman*'
Search:  pacman-foo

	Now try 'set -f' to disable pathname expanstion:

01:00 nirvana:~/scr/arch/tmp> set -f
01:02 nirvana:~/scr/arch/tmp> ./tst.sh pacman*
Search:  pacman-foo
01:02 nirvana:~/scr/arch/tmp> ./tst.sh 'pacman*'
Search:  pacman-foo

	Huh? Now try 'set -o noglob'

01:02 nirvana:~/scr/arch/tmp> set -o noglob
01:03 nirvana:~/scr/arch/tmp> ./tst.sh pacman*
Search:  pacman-foo
01:04 nirvana:~/scr/arch/tmp> ./tst.sh 'pacman*'
Search:  pacman-foo

	Huh? Again..  What gives is it bash or is it something I'm reading wrong?


-- 
David C. Rankin, J.D.,P.E.
Rankin Law Firm, PLLC
510 Ochiltree Street
Nacogdoches, Texas 75961
Telephone: (936) 715-9333
Facsimile: (936) 715-9339
www.rankinlawfirm.com

[arch-general] bash - pathname expansion controls 'set -f' or 'set -o noglob' on broken?

David C. Rankin

mike rosset

David C. Rankin

David C. Rankin

mike rosset

C Anthony Risinger

David C. Rankin

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