Sed emptying file when i use for search replace operation

Shell Programming and Scripting
1

Hi Friends

I am new to sed programming , i found that the below code can search for the $ToSearch and Replace it with $ToReplace ( $ToSearch and $ToReplace are my variables in my script )

sed "s/$ToSearch/$ToReplace/" $file > $output
mv $output $file

In testing the script i found that this is emptying the file if
$ToSearch="*** to search "
Note: i want to search for the string " to search *** " [ '' not to replace with any character ]
How to handle with the wild characters in search and replace operations ?

2

Try this...

ToSearch="\*\*\* to search \*\*\*\*"

root@bt:/tmp# cat inputfile 
**** ahamed ****
ahamed ahamed
root@bt:/tmp# srch='\*\*\*\* ahamed \*\*\*\*'
root@bt:/tmp# sed "s/$srch//g" inputfile 

ahamed ahamed

--ahamed

3

thanks ahamed

i want to use the script for general purpose like

srch

can contain any text , like i don't want to hardcode the script for only

"*** to search ***"

pattern

How can we achieve that ?

4

Not sure if this can be done in a better way...

#!/bin/bash
srch='**** ahamed ****'
srch=$(echo "$srch" | sed 's/\*/\\\*/g')
sed "s/$(echo "$srch")//g" input_file > output_file

--ahamed