How can i use fork,sleep,wait and write in a process with father and son..??

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

Process remians in Running state causing other similar process to sleep and results to system hang

Hi Experts, I am facing one problem here which is one process always stuck in running state which causes the other similar process to sleep state . This causes my system in hanged state. On doing cat /proc/<pid>wchan showing the "__init_begin" in the output. Can you please help me here...

2. BSD

Process remians in Running state causing other similar process to sleep and results to system hang

3. Shell Programming and Scripting

Sleep 600 or fork/spawn a process or daemon?

Hi, I have a script that run every 10 minutes, from a specific timeframe of the day, for example 0500 - 1900. The script is some sort of checker script for an application log file and check for errors and email us if there is error/s reported in the log. At the moment, I schedule it...

4. Programming

Linux fork, execv, wait question

Hi All, I have a program for class that needs to do the following: 1. Print the directory entries from the current directory using ncurses 2. Provide a prompt next to each directory entry and allow the user to enter commands that may or may not be about the file 3. Execute those commands in...

5. Programming

Newbie question on exec,fork, wait,pipe C

Hello everybody.I want to make clear that i am not going to ask from anybody to build my asignement but i have a big problem. I can't seem to find anywhere ONE good example on C about what i am trying to do:wall:.I think it is simple. All i ask is one example, even a link is fine. So, i want to...

6. Red Hat

Fork wait in background process - large delay

hi all, We are trying to run a process in the background and in the process we call fork ;and wait for the child process to finish .We find that the died = wait(&status); happens after 10 seconds randomly and sometimes completes in time (within 1 sec) This behavior is seen only when the...

7. Red Hat

Fork wait in background process - large delay

8. Shell Programming and Scripting

help in wait or sleep command

Hi All, I have a script which runs 3 scripts. The first script creates two files. The other two scripts should run only when the files are created. I tried the following for loop , but it is not working. Can someone please help me. while ; do # Sleep until file does exists/is created...

9. Shell Programming and Scripting

wait command - cat it wait for not-chile process?

Did not use 'wait' yet. How I understand by now the wait works only for child processes, started background. Is there any other way to watch completion of any, not related process (at least, a process, owned by the same user?) I need to start a background process, witch will be waiting...

10. UNIX for Dummies Questions & Answers

wait / sleep what to use???

Hi I have a script, where i need to execute the follwoing scripts/commands in my script. but those should be executed one by one cd /aa/205/jams .cmd/mass_all.sh - -> execution of this will take atleast 20-30mins cd $HOME/precompile ant-Ddir.location=$HOME/tomcat/webapps - -> execution of...

LEARN ABOUT MOJAVE

fork

FORK(2) 						      BSD System Calls Manual							   FORK(2)

NAME

     fork -- create a new process

SYNOPSIS

     #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.

LEGACY SYNOPSIS

     #include <sys/types.h>
     #include <unistd.h>

     The include file <sys/types.h> is necessary.

SEE ALSO

     execve(2), sigaction(2), wait(2), compat(5)

HISTORY

     A fork() function call appeared in Version 6 AT&T UNIX.

CAVEATS

     There are limits to what you can do in the child process.	To be totally safe you should restrict yourself to only executing async-signal
     safe operations until such time as one of the exec functions is called.  All APIs, including global data symbols, in any framework or library
     should be assumed to be unsafe after a fork() unless explicitly documented to be safe or async-signal safe.  If you need to use these frame-
     works in the child process, you must exec.  In this situation it is reasonable to exec yourself.

4th Berkeley Distribution					   June 4, 1993 					 4th Berkeley Distribution

UNIX for Dummies Questions & Answers