Shell Scripting

Scan text file to find all words of 4 characters or less

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Join Date: Dec 2005

Posts: 2

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darklord

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Scan text file to find all words of 4 characters or less

Dec 8th, 2005

What I am trying to do is to scan a text file word by word and find all words of 4 character or less then output these words to a file, but the problem is I don't know a unix command that can scan the file this way. The Grep command only enable me to find a certain word in a file. Any help is appreciated

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Join Date: May 2004

Posts: 178

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jim mcnamara jim mcnamara is offline

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Re: Scan text file to find all words of 4 characters or less

Dec 8th, 2005

try awk. This is a start:

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
awk '{ 
       for(i=1;i<=NF;i++) 
       {
         if(length($i)<5) 
         {print $i}
       }
       }'  filename  > newfilename
awk '{ 
       for(i=1;i<=NF;i++) 
       {
         if(length($i)<5) 
         {print $i}
       }
       }'  filename  > newfilename

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Join Date: Dec 2005

Posts: 2

Reputation: darklord is an unknown quantity at this point

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darklord

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Re: Scan text file to find all words of 4 characters or less

Dec 9th, 2005

•

Originally Posted by jim mcnamara

try awk. This is a start:
Help with Code Tags

Shell Scripting Syntax (Toggle Plain Text)
awk '{ 
       for(i=1;i<=NF;i++) 
       {
         if(length($i)<5) 
         {print $i}
       }
       }'  filename  > newfilename
awk '{ for(i=1;i<=NF;i++) { if(length($i)<5) {print $i} } }' filename > newfilename

Thank you.

Taking this step further. How can I filter out these 4 or less characters words, so that the newfilename only contain palindromes words?

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Join Date: May 2004

Posts: 178

Reputation: jim mcnamara is on a distinguished road

Solved Threads: 10

jim mcnamara jim mcnamara is offline

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Junior Poster

Re: Scan text file to find all words of 4 characters or less

Dec 12th, 2005

We are now clearly doing homework.

This is the limit of help->
1. redirect the output of the awk script into a loop instead of into a file.

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
for word in `awk script above`
do
 
done
for word in `awk script above`
do

done

the part between do ... done is now yours.
read the man page for rev, and learn how to compare two strings in an if statement.
use one string for the original version of the $word variable, and reverse another.