ASGAUR

What does fork() do? #include #include

What's the difference between fork() and vfork()? Some systems have a system call

Why use _exit rather than exit in the child branch of a fork? There are a few dif

Creating new processes: fork()

What's the return value of system/pclose/waitpid? The return value of

How do I find out about a process' memory usage? Look at getrusage() , if availa

Why do processes never decrease in size? When you free memory back to the heap wi

How do I change the name of my program (as seen by `ps')? On BSDish systems, the

So where do I put my configuration files then? The correct directory for this usu

How can I find a process' executable file? This would be a good candidate for a l

Why doesn't my process get SIGHUP when its parent dies? Because it's not supposed

How can I kill all descendents of a process? There isn't a fully general approach

How can I get/set an environment variable from a program? Getting the value of an

How can I read the whole environment? If you don't know the names of the environm

Environment variables

How can I sleep for less than a second? The sleep() function, which is availabl

How can I get a finer-grained version of alarm()? Modern Unixes tend to implement

How can a parent and child process communicate? A parent and child can communicat

What is a zombie? When a program forks and the child finishes before the parent,

How do I prevent them from occuring? You need to ensure that your parent process

How do I get rid of zombie processes?

How do I get my program to act like a daemon? A daemon process is usually defin

How can I look at process in the system like ps does? You really don't want to

Given a pid, how can I tell if it's a running program? Use kill() with 0 for th

How do I use select()? The interface to select() is primarily based on the conc

How do I use poll()? poll() accepts a pointer to a list of struct pollfd , in

Can I use SysV IPC at the same time as select or poll? No. (Except on AIX, whic

How to manage multiple connections? I have to monitor more than one (f

What is a named pipe? A named pipe is a special file that is used to transfer d

How do I create a named pipe? To create a named pipe interactively, you'll use ei

How do I use a named pipe? To use the pipe, you open it like a normal file, and u

Can I use a named pipe across NFS? No, you can't. There is no facility in the NFS

Can multiple processes write to the pipe simultaneously? If each piece of data wr

Using named pipes in applications How can I implement two way communic

What can I do with named pipes (FIFOs)?

How can I tell when the other end of a connection shuts down? If you try to read

Best way to read directories? While historically there have been several differen

How can I find out if someone else has a file open? This is another candidate for

How do I `lock' a file? There are three main file locking mechanisms available. A

How do I find out if a file has been updated by another process? This is close to

How does the `du' utility work? du simply traverses the directory structure cal

How do I find the size of a file? Use stat() , or fstat() if you have the file

How do I expand `~' in a filename like the shell does? The standard interpretatio

How can I make my program not echo input? How can I make my program no

How can I read single characters from the terminal? How can I read sin

How can I check and see if a key was pressed? How can I check and see

How can I move the cursor around the screen? How can I move the cursor

What are pttys? Pseudo-teletypes (pttys, ptys, other variant abbreviations) are

Serial device names and types The device names used for serial port devices vary

Setting up termios flags Some hints on setting up the termios flags when using a

How to handle a serial port or modem? The handling of serial devices under Unix i

How can I tell how much memory my system has? This is another `Frequently Unanswe

How do I get a user's password? Traditionally user passwords were kept in the `/

How do I get shadow passwords by uid? My system uses the getsp* suite

How do I verify a user's password? The fundamental problem here is, that various

How do I check a user's password?

How do I compare strings using filename patterns? Unless you are unlucky, your sy

How do I compare strings using regular expressions? There are a number of slightl

How do I compare strings using wildcards? The answer to that depends on what ex

The simple method: /bin/mail For simple applications, it may be sufficient to inv

Invoking the MTA directly: /usr/lib/sendmail The mail program is an example of

What's the best way to send mail from a program? There are several ways to send e

How can I debug the children after a fork? Depending on the tools available there

How to build library from other libraries? Assuming we're talking about an archiv

How to create shared libraries / dlls? The precise method for creating shared lib

Can I replace objects in a shared library? Generally, no. On

How can I generate a stack dump from within a running program? Some systems provi

$Id: rawfaq.texi,v 1.37 2000/09/01 06:34:57 andrew Exp $