COP 3344-01 Introduction to Unix: Lecture 7

Learning objectives

After this class, you should be able to:

1. Write simple makefiles, and use make to build targets.
2. Given a makefile, timestamps on the files, and the make command, give the commands executed by make.

Reading assignment

1. JEA: Appendix G, Make tutorial.
2. Lecture slides: Lecture 7.

Exercises and review questions

• Questions on current lecture's material
  1. Modify the first makefile example from Lecture 7 so that it has an additional rule to backup a file named file3. Try updating file3 and see how make backs it up. Try running make without updating file3, and see the action performed by make.
  2. Modify the above makefile so that a default target called all backs up file1, file2, and file3 when necessary.
  3. Modify the above makefile so that the name of the program that performs the backup is given as a macro.
  4. Modify the above makefile so that the backup files are also backed up. That is, if file1 is modified, then file1.bak is backed up in a file called file1.bak.bak, and file1 is backed up in file1.bak. Similarly, if the user updates file1.bak directly, then file1.bak should be backed up in the file file1.bak.bak.
  5. (Optional) Read about the crontab command and see how you can have your files backed up automatically, say, every day.

• Questions on next lecture's material
  1. Create a few text files which include a few lines containing the word program. Use grep to search for all lines containing the word program in all files that end in .txt in the current working directory.