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grep '^[a-zA-Z]'

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Join Date: May 2007

Posts: 5

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Toktam

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grep '^[a-zA-Z]'

Jun 4th, 2007

Hi everyone,

What does this command mean?
grep '^[a-zA-Z]'

Cheers,

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Join Date: Feb 2006

Posts: 2,432

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masijade

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Nearly a Posting Maven

Re: grep '^[a-zA-Z]'

Jun 6th, 2007

I assume this is coming after some other command, right? Such as cat somefile.

So, what the following pipeline command does

 Help with Code Tags 
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cat somefile | grep "^[a-zA-Z]"
cat somefile | grep "^[a-zA-Z]"

is return all lines that start with a letter, whether capital or not. Effectivly filtering out all lines that do not.

That is, as long as it is double quotes (") that are used. I believe that if it is single quotes (') are used, that it will only return those lines that contain (anywhere in the line) exactly those characters. I do not have a *nix system at hand, currently, to check that again though, and it has been a while since I have been able to work extensivly on an *nix system.

Java Programmer and Sun Systems Administrator

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Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.
--Brian Kernighan

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Join Date: Jun 2007

Posts: 11

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vrgurav

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Re: grep '^[a-zA-Z]'

Jun 19th, 2007

^ indicate from begining of the line
[] indicates individual occurance

hence it will display all the lines having haracter between A-Z or a-z

•

Originally Posted by Toktam

Hi everyone,

What does this command mean?
grep '^[a-zA-Z]'

Cheers,

•

Join Date: Jun 2007

Posts: 11

Reputation: vrgurav is an unknown quantity at this point

Solved Threads: 1

vrgurav

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Re: grep '^[a-zA-Z]'

Jun 19th, 2007

^ indicate from begining of the line
[] indicates individual occurance

hence it will display all the lines having character between A-Z or a-z

•

Originally Posted by Toktam

Hi everyone,

What does this command mean?
grep '^[a-zA-Z]'

Cheers,

•

Join Date: Jun 2007

Posts: 11

Reputation: vrgurav is an unknown quantity at this point

Solved Threads: 1

vrgurav

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Re: grep '^[a-zA-Z]'

Jun 19th, 2007

cat somefile | grep "^[a-zA-Z]"

it will direct the output of first command
ie cat somefile to grep command
and grep will give from first column of somefile all data having character between A-Z or a-z