Looking for an easy way to add escape charaters to a string in BASH.

[pronerd]

Hi,

I was wondering if any one knows of an easy way to add escape characters to an existing string in a BASH script.

I have a BASH script that is failing when a string is passed with brackets "[]" are passed to the sed command.

I am trying to put together a BASH script to create Unix safe file names. i.e. Removes spaces, special characters, etc.


This fails due to the brackets. It returns "/opt/content2/Transformers_The_Album/test blah[file].txt" instead of "/opt/content2/Transformers_The_Album"

somePath="/opt/content2/Transformers_The_Album/test blah[file].txt"
highestLevel="test blah[file].txt"
echo "$somePath" | sed "s/\/$highestLevel//g"
 
Returns :  /opt/content2/Transformers_The_Album/test blah[file].txt
 
 

If I manually escape the brackets "[]" then it works.

somePath="/opt/content2/Transformers_The_Album/test blah[file].txt"
highestLevel="test blah\[file\].txt"
echo "$somePath" | sed "s/\/$highestLevel//g"
 
Returns :  /opt/content2/Transformers_The_Album
 

I was wondering if anyone knew of an command, or other simple way to add the needed escape characters to a string. I was hoping to avoid having to create all of the logic to parse the string and add the characters as needed.

[radoulov]

Check the printf q option:

$ printf "%s" "$somePath" | sed "s_$(printf "%q" "$highestLevel")__g"
/opt/content2/Transformers_The_Album/

And perhaps you don't need sed:

$ printf "%s\n" "${somePath%/*}/"
/opt/content2/Transformers_The_Album/

Or (if you need to be specific):

$ printf "%s\n" "${somePath/$highestLevel}"
/opt/content2/Transformers_The_Album/