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Old 04-23-2009, 06:28 AM   #1
babu198649
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echo $(i++) does not work

Hi,
echo $(i++) does not work on a shell does not increment the variable i.Where as echo $((i++)) works fine .So what's the difference between the two.

Thanks in advance.
 
Old 04-23-2009, 06:33 AM   #2
Libu
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Pretty simple "(( ))" is integer expansion, whereas "( )" is just a way to create a new shell to run commands.
 
Old 04-23-2009, 06:38 AM   #3
babu198649
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Thanks,
Do you know any material on the internet from which i can find more info on this.I am following "The Unix Programming Environment" book and i did not find the info over there.
 
Old 04-23-2009, 06:39 AM   #4
Libu
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You will have to add spaces:
Quote:
echo $(( i++ ))
 
Old 04-23-2009, 06:41 AM   #5
Libu
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This is one of the best that I have come across. I use it all the time:
http://tldp.org/LDP/abs/html/
 
Old 04-23-2009, 06:43 AM   #6
pixellany
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Quote:
Originally Posted by Libu View Post
This is one of the best that I have come across. I use it all the time:
http://tldp.org/LDP/abs/html/
At the same site, start with Bash Guide for Beginners
 
Old 04-23-2009, 06:43 AM   #7
babu198649
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Thanks for the link
Quote:
You will have to add spaces:
Even without spaces it works fine for me .
[sb@isro ~]$ echo $((i++))
7
 
  


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