Sed doesn't update file in bash script

chilebiker · 06-13-2007, 05:46 PM

I'm writing a bash script that updates my website, but I'm having a problem with sed.

Code:

sed -ri 's:blablabla:muahaahaa:' test.html

works on the command line, but using the same command in the script doesn't update my file. My test script:

Code:

#!/bin/bash

Test_File="test.html"
if [ "$1" -eq 1 ]
then
  Search_String="blablabla"
  Replace_String="muahaahaa"
else
  Search_String="muahaahaa"
  Replace_String="blablabla"
fi

sed -ri 's:$Search_String:$Replace_String:' $Test_File
echo "old: ${Search_String}"
echo "new: ${Replace_String}"

exit 0

I've been working on this all afternoon, but haven't found a solution. Any help appreciated!

Edit: I've been posting this a couple of minutes too early, I found the solution. The sed-command in the script must be without single quotes (').

dxqcanada · 06-13-2007, 06:09 PM

I think you need single quotes around the variable so that sed does not think it is a regular expression.

Code:

sed -ri 's:'$Search_String':'$Replace_String':' $Test_File

chilebiker · 06-13-2007, 06:46 PM

@dxqcanada
Yes, that works as well. Might be safer to use it your way - thanks!

cfaj · 06-13-2007, 09:43 PM

Quote:

Originally Posted by chilebiker

I'm writing a bash script that updates my website, but I'm having a problem with sed.

Code:

sed -ri 's:blablabla:muahaahaa:' test.html

works on the command line, but using the same command in the script doesn't update my file. My test script:

Code:

#!/bin/bash

Test_File="test.html"
if [ "$1" -eq 1 ]
then
  Search_String="blablabla"
  Replace_String="muahaahaa"
else
  Search_String="muahaahaa"
  Replace_String="blablabla"
fi

sed -ri 's:$Search_String:$Replace_String:' $Test_File
echo "old: ${Search_String}"
echo "new: ${Replace_String}"

exit 0

I've been working on this all afternoon, but haven't found a solution. Any help appreciated!

Edit: I've been posting this a couple of minutes too early, I found the solution. The sed-command in the script must be without single quotes (').

But do enclose it (and the filename) in double quotes:
Code:
sed -ri "s:$Search_String:$Replace_String:" "$Test_File"

chilebiker · 06-14-2007, 08:25 AM

After plenty of testing and playing around i found out that the following code works best:

Quote:

sed -ri s:"$Search_String":"$Replace_String": $File_Name

No quotes for s:..:..:, but both arguments enclosed in double quotes