Write a program (similar to logger(1)) that uses syslog(3) to write arbitrary messages to the system log file. As well as accepting a single command-line argument containing the message to be logged, the program should permit an option to specify the level of the message.

Log in as a normal, unprivileged user, create an executable file (or copy an existing file such as /bin/sleep), and enable the set-user-ID permission bit on that file (chmod u+s). Try modifying the file (e.g., cat >> file). What happens to the file permissions as a result (ls l)? Why does this happen?