09-28-2013
Thanks for the reply..sorry if the code is misleading but I was following an online tutorial to learn network programming.
All i want to do is to keep client in a loop until the user types "quit" so I will change while to do-while.
The client enters an infinite loop in which it queries the user which service is being requested. There are two options : echo and time.
The client forks off a child. After the child is forked off, the parent process enters a second loop in which it continually reads and prints out status messages received from the child via a half-duplex pipe.
I hope it clears some part of what I want to implement.
So i thought of :
do
{
if user enters "echo"
then
it will fork off a child, doEcho() but what to do after that..I am not getting as
per the requirement like parents goes in infinte loop and all..
else if user enters "daytime"
then
it will fork off a child , doDayTime() and again the same.what to do/.
}while (user enters exit)
I guess I am following the right track???
Please guide me.
Thanks and Regards
Abhinav
Last edited by abhi1988sri; 09-28-2013 at 05:56 AM..
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LEARN ABOUT OPENDARWIN
fork
FORK(2) BSD System Calls Manual FORK(2)
NAME
fork -- create a new process
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
pid_t
fork(void);
DESCRIPTION
Fork() causes creation of a new process. The new process (child process) is an exact copy of the calling process (parent process) except for
the following:
o The child process has a unique process ID.
o The child process has a different parent process ID (i.e., the process ID of the parent process).
o The child process has its own copy of the parent's descriptors. These descriptors reference the same underlying objects, so that,
for instance, file pointers in file objects are shared between the child and the parent, so that an lseek(2) on a descriptor in the
child process can affect a subsequent read or write by the parent. This descriptor copying is also used by the shell to establish
standard input and output for newly created processes as well as to set up pipes.
o The child processes resource utilizations are set to 0; see setrlimit(2).
RETURN VALUES
Upon successful completion, fork() returns a value of 0 to the child process and returns the process ID of the child process to the parent
process. Otherwise, a value of -1 is returned to the parent process, no child process is created, and the global variable errno is set to
indicate the error.
ERRORS
Fork() will fail and no child process will be created if:
[EAGAIN] The system-imposed limit on the total number of processes under execution would be exceeded. This limit is configuration-
dependent.
[EAGAIN] The system-imposed limit MAXUPRC (<sys/param.h>) on the total number of processes under execution by a single user would
be exceeded.
[ENOMEM] There is insufficient swap space for the new process.
SEE ALSO
execve(2), wait(2)
HISTORY
A fork() function call appeared in Version 6 AT&T UNIX.
4th Berkeley Distribution June 4, 1993 4th Berkeley Distribution