Read from file > process > output to file - Shell Programming and Scripting

Lorna · #1 (**permalink**) 10-05-2008

Hi all,

OK, I am totally new to shell scripting as I just started today. All I want from shell scripting is something very basic, and I've been searching for tutorials on "processing files" and I could not find a suitable one for my level.

I want to read two columns from a data file, one raw at a time, use these values as input to some program, then parse the output of that program (output is text) and append important info to another file

I am going insane about this, please help me find a useful tutorial!!!

Thanks

danmero · #2 (**permalink**) 10-05-2008

This is a very "first time question"

The basic concept should be:

Code:

while read col1 col2
do 
  echo $col1 >> output.file
  echo $col2 >> output.file
done < data.file

For solutions you can use the search tab on this forum... or Google for tutorials for your shell.

Lorna · #3 (**permalink**) 10-06-2008

Thank you so much, that's very helpful!!

matrixmadhan · #4 (**permalink**) 10-06-2008

Quote:

Originally Posted by danmero

This is a very "first time question"

The basic concept should be:

Code:

while read col1 col2
do 
  echo $col1 >> output.file
  echo $col2 >> output.file
done < data.file

For solutions you can use the search tab on this forum... or Google for tutorials for your shell.

this is much better, no need to open and close files multiple times

Code:

while read col1 col2
do 
  echo $col1 
  echo $col2 
done < data.file >> output.file

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