Shell Programming and Scripting

Hi,

To make it clear, My output file will contain the path of the directory present somewhere in it. I am assigning this path to a variable because the path might keep changing. That is i am using a diff command to check if any additional files are present in any of the two directories i am comparing. The command displays in my output the additional file present in it as
only in a/b/c/d File1.txt.
Where a/b/c/d is the path. I dont want to expose the path in my output file.Instead i need to replace it with the input which i accept from the user.I am adding few more strings to the user input and assigning to another variable. So wherever i find the path in my output file i need to replace it with the modified user input.

assuming my variable are var1 and var2. When i tried
sed -e "s#$var1#$var2#" filename it didnt work.


2nd question

sed -e "s#$variable#sbcd#" filename

This command replaces $variable with the sring sbcd. What if i need to replace sbcd with the variable?

sed -e "s#sbcd#$variable#" filename - is not working.

Is it clear now?

Based on my understanding,Let us assume the directory user inputs is in the variable $USERIN.Now you want to do filter the output file so as to replace the exact directory path with the one user provides/inputs.

Code:

sed -e s#path_to_replace#$USERIN# file.txt

But the above code doesn't modify the file,it just extracts the contents and display it to you.If you want to alter the file please do this :

Code:

sed -e s#path_to_replace#$USERIN# file.txt > file1.txt
mv file1.txt file.txt

"The redirection symbol ">" directs the output from sed to the file newfile. Don't redirect the output from the command back to the input file or you will overwrite the input file. This will happen before sed even gets a chance to process the file, effectively destroying your data."

Hi all,

Thanks for your help.

I used

sed "s#$var1#$var2#g" file.txt

It worked. It solved my requirements.and to replace a string with a variable i used
sed "s#string#$var#g" file.txt

This code is also working fine

sed -e s#path_to_replace#$USERIN# file.txt.

Thanks DILEEP410 .