CS 140
Practice problems on Files

Here are some practice programming problems using files.

These are not to be handed in, though you should feel free to ask questions about any of them outside of class. Remember that programming is an activity that you learn by doing.

1. Write a program that asks for a file name and then prints to the screen the contents of the file with that name.
2. Write a program that prints itself to the screen.
3. Write a program that asks for a file name and then prints to the screen the file with that name, only every instance of the word "bob" is replaced by "The Most Noble and Supreme BOB". Here is an idea for how to do this: each time you read a line, use the split( " ") function of lines (which we used in the Concordance program) to split the line into a list of words. If the word is not "bob", just print it, followed by a space. If it is "bob" then instead print the substitute, followed by a space.
4. One of the debugging quesitons in HW5 asked you how to open a file and add some text to the beginning. Do that. Write a program that opens up a file (perhaps the program itself) and adds the line
           # BOB RULES
   to the top of the file.
5. Write a program COPY that asks for the name of a file anthe name to give a copy. The program then makes a copy of the orginal file under the new name. Of course, the program shouldn't crash if the original file name doesn't match an actual file.
6. Write a program that reads a text file consisting of numbers, one number per line, and computes the average of all of these numbers..
7. Write a program that inputs a number N and then writes to a file "primes.txt" all of the prime numbers between 2 andN.