Midterm Information:

---
Format:

Short answer questions (55 points) and long answer questions
(3 questions, 45 points). At least two of the long answer questions
are related to Assignment 1 and Assignment 2.

Short answer question examples:

1) Write a code segment to block SIGINT and SIGUSR1

2) What is the content in file mytmp after the following code segment is
executed?

f1 = open ("mytmp", O_RDWR | O_CREAT, 0777);
f2 = open ("mytmp", O_RDWR | O_CREAT, 0777);
write(f1, "2222", 4);
write(f2, "1111", 4);
close(f1);
close(f2);

A long answer question example:

In the mymake program, the dependencies specified in the makefile must
be honored. Write the code (or very detailed pseudo-code) that enforces
the dependencies. Specify your assumptions and data structures.

----

Most questions are related to coding: writing code segments to achieve
certain tasks or predicting the output of a code segment (UNIX concepts are
embedded in such questions).

----

Content: Lecture 1 to Lecture 8

Lecture 2: General C/C++ programming and UNIX concepts

- gcc flags to enforce C/C++ standards
- makefile
- directives to protect C/C++ header files
- C/C++ macros with parameters
- command line arguments
- environ variable, getenv

Lecture 3: Process management

fork, exit, wait, waitpid, execv family routines
their semantics, how to use them, parent/child synchronization
zombie process, orphane process, various ids

Lecture 4: File operations and pipes

Data structure related to file operations

open, dup, read, write
semantics and how to use them

I/O redirection, what is it and how to code

unname pipes: pipes - semantics and how to use it
how to implement the pipe in shell

Lecture 5: File meta data and directories

The data structure storing file meta data, understand the fields
file type, set-user-ID and set-group-ID, access permission,
hard link and symbolic link, file time, random access
directory operations

stat, umask, remove, rename, link, unlink, symlink, readlink, lseek
opendir, readdir, closedir, rewinddir

Lecture 6: Signal and terminal IO

Common signals, block/unblock/caatch signals, set signal handler

sigprocmask, sigaction, kill, alarm

Terminal IO: canonical and noncanonical mode of input, how to set
to a particular mode?

tcgetattr, tcsetattr

Lecture 7: Job control and process relationship

UNIX process relationship: session/group process
Job control: what does it do?
foreground and background processes 

getpgrp, setpgid, setsid, tcgetpgrp, tcsetpgrp

Lecture 8: Inter-process communication

message queues, shared memory, semaphores
What are they? and the related system calls to create, use, and
destroy them.