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Old 06-05-2010, 01:39 PM   #1
u_Muhammad
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can we do pattern macting based on a variable ??


i have the follwing code
touch umer.txt
fdisk -l | grep 'Disk /' umer.txt
read file
#now i want to check the 'file' string exits in the umer.txt or not
#i have
cat umer.txt | grep $file


but it is not workig...
how to do that ????

Last edited by u_Muhammad; 06-05-2010 at 01:42 PM.
 
Old 06-05-2010, 02:09 PM   #2
Robhogg
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Simple answer, yes we can.

Have you checked that there's anything in the file umer.txt?

Quote:
fdisk -l | grep 'Disk /' umer.txt
This does nothing with the output of the fdisk command, and instad greps umer.txt for 'Disk /'. It should, I think, be:

Code:
fdisk -l | grep 'Disk /' > umer.txt # > is the redirect operator
Also, what pattern are you searching for (i.e. what are you entering at the "read" line)?

Last edited by Robhogg; 06-05-2010 at 02:35 PM. Reason: corrected tag
 
Old 06-05-2010, 02:23 PM   #3
u_Muhammad
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Yes sir, afer this cammad.
The file umer.txt contain
'Disk /dev/sda' and some other info.
now i want to check that if the user give input which is not in the umert.txt. then i will not work.
like if he enter abc then failed but if enters /dev/sda then continue.
 
Old 06-05-2010, 02:38 PM   #4
Robhogg
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So, are you wanting to do something like this?:

Code:
if ! cat umer.txt | grep $file; then 
      exit 1 # exit from script if no match
fi
It might help if you explain what it is that isn't working.
 
Old 06-05-2010, 02:59 PM   #5
u_Muhammad
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sir its not working....
it gives :
grep [option] pattern [File]
 
Old 06-05-2010, 03:10 PM   #6
pixellany
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Please post the actual commands you are using, and the resulting output (cut and paste from the terminal). Also, put the code into [code] tags. (Advanced mode--select the text, and click on #)
 
Old 06-05-2010, 03:11 PM   #7
Robhogg
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Quote:
Originally Posted by u_Muhammad View Post
grep [option] pattern [File]
Which means, I believe, that what you are entering is not a valid pattern for grep.

Could you give an example of what you are entering, please, and the full output.
 
1 members found this post helpful.
Old 06-05-2010, 03:47 PM   #8
u_Muhammad
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Sir, i have done it. Actually i was putting it in double quotes i think thats why it is giving error.
Thank you for your kind attention.
 
  


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