Exercises

1. Find and read the documentation of the time package.
2. Try to change the Go code of userFiles.go in order to support multiple users.
3. Change the Go code of insertLineNumber.go in order to read the input file line by line, write each line to a temporary file, and then, replace the original file with the temporary one. If you do not know how and where to create a temporary file, you can use a random number generator to get a temporary filename and the /tmp directory to temporarily save it.
4. Make the necessary changes to multipleMV.go in order to print the files that are a match to the given regular expression without actually renaming them.
5. Try to create a regular expression that matches PNG files and use it to process the contents of a log file.
6. Create a regular expression that catches a date and a time string in order to print just the date part and delete the time part.