Weird sed behaviour in script

Peetrus · #1 (**permalink**) 08-30-2008

I've written a small script to replace certain words in all the the files in a directory.

Code:

#!/bin/sh

#Get list of files to be edited

file_list=`ls -p`

for i in $file_list
do
echo "Processing $i"

alteredi=`echo "$i" | sed -e 's/\//d/'`

if [ $i = $alteredi ]
then
	if [ $i != "maketest" ]
	then
	#actual altering
	
	cat $i | sed -e "s/login\//login.tst\//" > $i
	cat $i | sed -e "s/cyberkd\//cyberkd.tst\//" > $i
	cat $i | sed -e "s/\/db_connect.inc.php/\/testdb_connect.inc.php/" > $i
	echo "  $i has been altered"
	else
	echo "  Not altering myself"
	fi

else
echo "  Not altering directories"
fi

done

Now, when I run this script as a normal user, only the first 4kB of the file is processed. So all files larger than 4kB are cut in half. The remaining bytes are just left out of the new file. When I ran the script as root, 8kB were processed. Is there a way to process the entire files?

When I cat a large text file the entire file gets printed on my screen.

Thanks in advance.

Franklin52 · #2 (**permalink**) 08-30-2008

Don't read and write to the same file and using cat with sed is redundant, replace these lines:

Code:

cat $i | sed -e "s/login\//login.tst\//" > $i
cat $i | sed -e "s/cyberkd\//cyberkd.tst\//" > $i
cat $i | sed -e "s/\/db_connect.inc.php/\/testdb_connect.inc.php/" > $i

with:

Code:

sed -e "s/login\//login.tst\//" -e "s/cyberkd\//cyberkd.tst\//" -e "s/\/db_connect.inc.php/\/testdb_connect.inc.php/" "$1" > temp.file
mv temp.file "$1"

If you're sed version supports the -i flag you can edit the file in place without using a temporary file.

Code:

sed -i -e "s/login\//login.tst\//" -e "s/cyberkd\//cyberkd.tst\//" -e "s/\/db_connect.inc.php/\/testdb_connect.inc.php/" "$1"

Regards

Peetrus · #3 (**permalink**) 08-30-2008

Thank you. It works!

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