Hello I am writing script which takes 2 symbols and replaces the first with the second and also the script takes as an arguments files .The idea is to replace in the file the first character with the second here is the script:char_src=$1char_dest=$2shiftfor filedo    while read -r line    do        line=${line//$char_src/$char_dest}        echo $line    done < $filedoneThe problem is that it prints the contents right,but it doesn't save the changes to the file,I try to save them with  done < $file
Replacing characters in file
shell script;text processing