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Old 09-18-2008, 06:09 AM   #1
Registered: Oct 2007
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omit white spaces for pattern matching in shell script


In shell script i am searching for a pattern like this

value={ip = }

if [[ $value == {ip* ]]

but if i have n no. of white spaces between "{" and "ip"

for example

value={ ip = }

my pattern matching does not work.

How do i have have a general pattern matching in which i can have n no. of white spaces or no white spaces between "{" and "ip"?

Can somebody help me?
Old 09-18-2008, 06:31 AM   #2
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To match spaces, use quotes:
if [[ "aa" == " aa" ]]; then 
  echo match
  echo no match
Should output "no match" because of the leading space on the second operand. You can still use variables, e.g.
v=" aa"
if [[ "$v" == " aa" ]]; then 
  echo match
  echo no match
Should output "match".
Old 09-18-2008, 07:43 PM   #3
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Do you really need to match on the '{' as well ?
Try a regex:
Old 09-18-2008, 07:50 PM   #4
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you can use simple case/esac
# s="value={ip = }"
# case $s in
> value={*ip* ) echo $s;;
> esac
value={ip = }
# s="value={ ip = }"
# case $s in  value={*ip* ) echo $s;; esac
value={ ip = }
Old 09-18-2008, 08:25 PM   #5
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To match on particular characters separated by any number of "whitespace" bytes:


matches all of the following:
abc def
abc  def
abc   def
The whitespace can be tabs or spaces

Last edited by pixellany; 09-19-2008 at 01:09 AM.


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