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Milestone 1

Memory leaks and undefined behaviors are not tested in the milestone.

All of the test cases are very basic input, and we'll give hints on many common errors. You'll get -50% deduction of a certain (sub)task if you get a wrong answer in any of its cases.

For example, if you get accepted in task 4.1 - 4.3, but get wrong answer in task 4.4, you will get a deduction of one mark (half of the total 2 marks).

Tasks

1. Write a working read/parse/execute loop and an exit command; [5]

• Case: 1
• Don't forget to print "exit" when exiting your shell

2. Handle single commands without arguments (e.g. ls); [5]

• Case: 2-4
• One of test command is exactly "ls"

3. Support commands with arguments (e.g. apt-get update or pkgin update); [5]

• Case: 5-6
• One of test command is exactly "ls -al"

4. File I/O redirection: [5+5+5+2]

4.1 Output redirection by overwriting a file (e.g. echo 123 > 1.txt); [5]

• Case: 7-8

4.2 Output redirection by appending to a file (e.g. echo 465 >> 1.txt); [5]

• Case: 9-10

4.3 Input redirection (e.g. cat < 1.txt) [5]

• Case: 11-12
• Should complete task 4.1 before this task

4.4 Combine 4.1 and 4.2 with 4.3; [2]

• Case: 13-14
• Should complete task 4.1 - 4.3 before this task

5 Support for bash style redirection syntax (e.g. cat < 1.txt 2.txt > 3.txt 4.txt); [8]

• Case: 15-18
• Space are not needed between <,>,>> and other characters (16)
• The position of <,>,>> can be arbitrary (17)