System Notes and Examples

System Notes and Examples

Mostly notes:

What is a filter?
Command Syntax.
Make files.
Include files, libraries, shared and dynamic libraries.
System calls.
What is a file?
File I/O; Files and Directories.
File Locking.
Memory Mapped I/O.
Process segments.
File descriptors and open files (diagram in gif or pdf - See note below).
Memory layout of C process (diagram in gif or pdf - See note below).
Pipe, fork and exec and related process control topics, such as wait and job control.
How a Bourne type shell does pipelines and lists (diagram in gif or pdf - See note below).
FIFO - named pipes.
Exit status as seen on a shell command.
Executing shell commands from a C program.
Signals including signal handlers and sigaction.
Concurrency and operating systems.
Threads:
- Thread generalities and POSIX threads.
- Kinds of threads (diagram in gif or pdf - See note below).
- A simple POSIX threads example: pthreads.c. Use this makefile.
A mini glossary.

Note: The gif files are faster and more convenient for viewing, but the pdf files gives better results if you wish to print the documents.
Mostly examples:

Determining some system limits.
Determining maximum file name length.
Seconds since epoch (1970 Jan 1).
Big holes in files.
Reading back through the stack.
jobcntl.c is a program which job controls job (source job.c). Change the SRCDIR definition in jobctnl.c to suit. Make sure you have a console window open so you can read the trace messages. (On SUN's CDE use the workspace menu to open a console window; the window should have name ``console'' not ``terminal''.)
sigmask.c shows how to mask a signal. All the the signal demos use reliable signalling, not signal( ).
sigtmpfile.c shows how to remove a temporary file prior to an interupt, and also shows a library function that does something similar and is easier to use. Nevertheless, the function is not always what you want.
sigmenu.c shows how a siglongjmp can be used with signals to abort from within some code. An editor might want to do something similar.
^D and EOF handling by terminal driver.
ttyraw.c shows how to set the terminal into raw mode and have a read timer.
Additional references:

/ and /usr file systems on Solaris (SUN documentation): / and /usr File Systems Changes and related SUN documentation.

Last update: 2009 January 22