Putting the results of grep & cut in a variable in a bash script
Here is a working version of your code with the changes commented as to why they were made.
#!/bin/bashfunction latest_file_name { local url="http://wordpress.org/latest.tar.gz" curl -s --head $url | # Add -s to remove progress information # This is the proper place to remove the carridge return. # There is a program called dos2unix that can be used as well. tr -d '\r' | #dos2unix # You can combine the grep and cut as follows awk -F '=' '/^Content-Disposition/ {print $2}'}function main { local file_name=$(latest_file_name) # [[ uses bash builtin test functionality and is faster. if [[ -e "$file_name" ]]; then echo "File $file_name does already exist!" else echo "There is no file named $file_name in this folder!" fi}main