Extract specific strings from line in file and output to another file with modifications

Question

New to linux and trying to escape doing this the hard way. I have a file ("output.txt") that contains the results of a 'find' command. Example first three lines from "output.txt":

/home/user/temp/LT50150292009260GNC01/L5015029_02920090917_MTL.txt
/home/user/temp/LT50150292009276GNC01/L5015029_02920091003_MTL.txt
/home/user/temp/LT50150292009292GNC01/L5015029_02920091019_MTL.txt

I'd like to use awk or sed (or similar) to extract two parts from the path listed for each line, and output to a new file ("run.txt") with extra information added on each line like so:

cd /home/user/temp/LT50150292009260GNC01; $RUNLD L5015029_02920090917_MTL.txt
cd /home/user/temp/LT50150292009276GNC01; $RUNLD L5015029_02920091003_MTL.txt
cd /home/user/temp/LT50150292009292GNC01; $RUNLD L5015029_02920091019_MTL.txt

I'm guessing this might also involve something like "cut", but I can't get my head wrapped around how to account for changing folder and file names.

Any help would be much appreciated.

score 1 · Answer 1 · answered May 07 '12 at 19:29

1

sed -e 's/^/cd /; s|/\([^/]*\)$|; \$RUNLD \1|' file

This prepends "cd " and replaces the last / with "; $RUNLD ". Voila!

answered May 07 '12 at 19:29

Jens

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Thanks Jens! It definitely worked as advertised, although not quite as complete as Dennis Williamson's answer. – Prophet60091 May 07 '12 at 20:08
No big deal. Dennis was one second quicker :-) Upvote appreciated, though. – Jens May 07 '12 at 20:09

score 1 · Answer 2 · answered May 07 '12 at 19:45

1

Just with bash

while IFS= read -r filename; do
  printf 'cd %s; $RUNLD %s\n' "${filename%/*}" "${filename##*/}"
done < output.txt > run

See http://www.gnu.org/software/bash/manual/bashref.html#Shell-Parameter-Expansion

answered May 07 '12 at 19:45

glenn jackman

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score 0 · Answer 3 · answered May 07 '12 at 19:13

I'd probably go about this with a loop based grep solution since I don't know cut, or awk very well haha. This does the trick:

while read x; do folder=$(echo "$x" | grep -o '^.*/'); file=$(echo "$x" | grep -o '[^/]*$'); echo "cd ${folder:0:-1}; \$RUNLD $file"; done < output.txt > run

score 0 · Accepted Answer · answered May 07 '12 at 19:28

0

sed 's|^|cd |; s|/\([^/]*\)$|; $RUNLD \1|' inputfile > run

It says:

insert "cd " at the beginning of the line
for the last slash and what comes after, substitute "; $RUNLD " and the final part (captured by the parentheses)

answered May 07 '12 at 19:28

Dennis Williamson

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Most complete answer, although Jens was a close second. – Prophet60091 May 07 '12 at 20:07

score 0 · Answer 5 · answered May 07 '12 at 23:01

This might work for you:

sed 's/\(.*\)\//cd \1; $RUNLD /' file
cd /home/user/temp/LT50150292009260GNC01; $RUNLD L5015029_02920090917_MTL.txt
cd /home/user/temp/LT50150292009276GNC01; $RUNLD L5015029_02920091003_MTL.txt
cd /home/user/temp/LT50150292009292GNC01; $RUNLD L5015029_02920091019_MTL.txt

Extract specific strings from line in file and output to another file with modifications

5 Answers5

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