how to set vriable for echo in linux command line

Question

I want to grep all file names in a directory, modify names, and print modified names by echo command:

file names:

merged.reversed.m444.txt.gz

merged.reversed.m445.txt.gz
...

modified should be:
m444
m445

for i in *; 
ModifiedName = sed 's/merged.reversed.//g' $i |  sed 's//.txt.gz/g'
do echo "modified name of file $i is $ModifiedName"; done

Answer 1

To create a variable from sed 's output use it like this:

for i in *; do
   ModifiedName=`echo "$i" | sed -e 's/merged\.reversed\.//' -e 's/\.txt\.gz//'`
   echo "modified name of file $i is $ModifiedName"
   mv "$i" "$ModifiedName"
done

Under BASH you could do:

ModifiedName=$(sed -e 's/merged\.reversed\.//' -e 's/\.txt\.gz//' <<< "$i")

Answer 2

I think you have some errors in your script.

A more correct version would be this one:

for i in *;
do
ModifiedName = `ls $i | sed -e s/merged\.reversed\.//g | sed -e s/\.txt\.gz//g`;
echo "modified name of file " $i " is " $ModifiedName;
mv $i $ModifiedName;
done

Note: To assign the value of the result of a command to a variable put the command into backticks (or $()) The . character is a special character so you need to backslash it to say to sed that you want to look for dots (otherwise you instruct it to look for ANY character)