Extracting a line in a text file - Shell Programming and Scripting

terryporter51 · #1 (**permalink**) 10-10-2008

If my file looks like this….
10
20
30
and I want to take each line individually and put it in a variable so it can be read
later in it's on individual test statement, how can I do that? I guess what I'm asking is how can I extract each line individually.

Thanks

otheus · #2 (**permalink**) 10-10-2008

Hopefully this gives you an idea.

Code:

cat yourfile.txt | while read line ; do 
   if [ $line == 30 ] ;then 
     echo I hit 30
   fi
done

vidyadhar85 · #3 (**permalink**) 10-10-2008

you can extract each line by using simple while

Code:

while read line
do
echo "$line"
##do any operation on that line
done < filename

otheus · #4 (**permalink**) 10-11-2008

We're both giving you essentially the same answer. When you mean "each line individually", do you mean you want each in its own variable? Bash3 supports arrays, so you could do it that way. If your file contains a fixed number of lines, say 3, you could do this:

Code:

cat yourfile.txt | {
  read line1
  read line2
  read line3

  # do stuff with line1 or line2 or line3
}

terryporter51 · #5 (**permalink**) 10-13-2008

I'm still having trouble stripping each line out so I can put it in it's on variable or text file.
i.e. I want 10 to be in a text file or set to a variable alone
20 set to be in a text file alone or in it's on variable and
30 set to be in a text file or set to it's on variable. I really want the position of the number because the number will change depending on the number of full tapes. Sorry guy's if this sound elementary all I want to do is grab which ever line I want 1-3 on call to my discretion.

Thx

danmero · #6 (**permalink**) 10-13-2008

Something like that:

Code:

eval $(awk '{print "line"NR"="$0}' file)
echo $line1
....

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