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# 1  
Old 01-17-2002
sed across multiple files

I've got a bunch of files (40 or so) and in each there is a substitution I need to perform.

I execuet the following sed command but it just make the changes to the screen without affecting the original file.

sed "s/, LA/,LA/g" *

(All files in the directory need this update).

So I tried redirecting...

for x in *
sed "s/, LA/,LA/g" $x > new_$x

And that worked. But I'm not sure about renaming the files back to what they were. mv obviously doesnt' like the wildcards and I'm not sure how to convert back.

I'd also like to know if there is a way to do this without piping to a new file...
# 2  
Old 01-18-2002
my try

there is probably a much better way to do this. Please forgive me I have never done any shell programming before (i want to learn) and I just wanted to rack my brain trying to figure out an answer to your problem. here is what I got to work for me. it does however pipe to a new file. sorry i couldn't help you there.

for x in *
sed "s/, LA/,LA/g" $x > temp
cat temp > $x
rm temp

just make sure you don't already have a file named temp. if yo do then just change the name temp to a file you don't already have.


Last edited by theDirtiest; 01-18-2002 at 09:56 AM..
# 3  
Old 01-18-2002
tweak script

I have a minor change to your script. Which will do the job.

Make a file with the listing of the files you want to change. This might be necessary if the directory your 40 files are in has other files that you don't want to change in it.

Make a file with only the filenames of your 40 files in it. Then do the script this way. (with backtics)

for x in `cat filename`
sed "s/, LA/,LA/g" $x > temp
cat temp > $x
rm temp

By default the 'sed' command will output all lines, even the ones it doesn't modify. If you did only want the lines that you modified to be output use this option 'sed -n ....'. This will suppress all lines that weren't modified.

Now that I think about it, you really don't need the 'rm temp' because your line, "sed "s/, LA/,LA/g" $x > temp", has only the '>' which will overwrite the temp file each time you come thru the 'for loop'.

So this will work as well.

for x in `cat filename`
sed "s/, LA/,LA/g" $x > temp
cat temp > $x


This User Gave Thanks to Kelam_Magnus For This Post:
# 4  
Old 01-18-2002
true you don't need the rm temp, but I just added it so it wasn't left over when the script was finished.
# 5  
Old 01-21-2002
Excellent..... in this instance all the files in the directory are to be modified...and i want all lines including those not modified,.. so a simple redirection to temp and back to $x will work just fine.

rm temp... harmless either that's cool. Thanks guys..


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