03-21-2006
about parent of processes INIT
as the kernal invokes a process INIT during the time of booting which in turn spawns all other processes because of which it is considered as parent process.
does it too calls system call fork() or there is something like this?
init() process2()
{
{ process3()
process2;
} } and so onnnnnnnnnnnnnn.
please dont mind if you think it a stupid question.because i am a student learning UNIX i want to know the UBDERLYING CONCEPTS and NOT JUST COMMANDS.
THANKS amor1
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hello all,
I got this little problem. I don't know what happen, but its not stopping work but is more of an FYI. I have this funny process running when I do ps -aef (on RedHat AS3 ) server I get this funny child process.
root 2345 1 .... /usr/bin/kdm -nodaemon
root... (6 Replies)
Discussion started by: larryase
6 Replies
2. Programming
i want to create 3 child processes from the same parent using folk. I know how to use folk but my child processes did not come from the same parent. Any suggestion what i did wrong ? (12 Replies)
Discussion started by: Confuse
12 Replies
3. UNIX for Dummies Questions & Answers
fork() system is used to create a child a process.lets consider fork() echo krace will print krace twice .if i give it in loop it will print krace 2 power n time..in this case all child and parent process executes same process ...but i want to create a four different child process to execute four... (4 Replies)
Discussion started by: kracekumar
4 Replies
4. Programming
Im sure it has something to do with the wait() call, but everything ive tried either leaves me with a zombie or with the exec executing indefinitely.
switch(pid = fork())
{
case -1:perror("fork failed");
exit(1);
case 0:
if(key == "cd")
{
execl("/bin/cd", "cd",... (2 Replies)
Discussion started by: p00ndawg
2 Replies
5. Shell Programming and Scripting
Hi All,
I have two ksh script. 1st script calls the 2nd script and the second script calls an 'C' program.
I want 1st script to wait until the 'C' program completes.
I cant able to get the process id for the 'C' program (child process) to make the 1st script to wait for the second... (7 Replies)
Discussion started by: sennidurai
7 Replies
6. Shell Programming and Scripting
Hi ,
I want to find out the child process name given its PID. I have used the ps command but it displays the parent process name against child PID.
Is there any way to find out name of child program executing under any parent program? (1 Reply)
Discussion started by: sneha_heda
1 Replies
7. Shell Programming and Scripting
Hey all, I need to launch a script from within 2 other scripts that can run independently of the two parent scripts... Im having a hard time doing this, if anyone knows how please let me know.
More detail.
ScriptA (bash), ScriptB (ksh), ScriptC (bash)
ScriptA, launches ScriptB
ScirptB,... (7 Replies)
Discussion started by: trey85stang
7 Replies
8. Shell Programming and Scripting
!/bin/sh
pid=$(ps -Aj | grep MSTRSvr | grep -v grep | awk '{print $1}')
sid=$(ps -Aj | grep MSTRSvr | grep -v grep | awk '{print $3}')
ps -s "$sid"
I am not able to get the desired output it says process list error
if i use watch ps -s "$sid" it considers only the first session id (5 Replies)
Discussion started by: schippada
5 Replies
9. Emergency UNIX and Linux Support
Hello, everyone.
Here's a program:
pid_t pid = fork();
if (0 == pid) // child process
{
execvp ...;
}
I send a signal (such as SIGINT) to the parent process, the child process receive the signal as well as the parent process.
However I don't want to child process to receive the... (7 Replies)
Discussion started by: jackliang
7 Replies
10. Shell Programming and Scripting
Hi everyone
i am very new to linux , working on bash shell.
I am trying to solve the given problem
1. Create a process and then create children using fork
2. Check the Status of the application for successful running.
3. Kill all the process(threads) except parent and first child... (2 Replies)
Discussion started by: vizz_k
2 Replies
LEARN ABOUT DEBIAN
unbuffer
UNBUFFER(1) General Commands Manual UNBUFFER(1)
NAME
unbuffer - unbuffer output
SYNOPSIS
unbuffer program [ args ]
INTRODUCTION
unbuffer disables the output buffering that occurs when program output is redirected from non-interactive programs. For example, suppose
you are watching the output from a fifo by running it through od and then more.
od -c /tmp/fifo | more
You will not see anything until a full page of output has been produced.
You can disable this automatic buffering as follows:
unbuffer od -c /tmp/fifo | more
Normally, unbuffer does not read from stdin. This simplifies use of unbuffer in some situations. To use unbuffer in a pipeline, use the
-p flag. Example:
process1 | unbuffer -p process2 | process3
CAVEATS
unbuffer -p may appear to work incorrectly if a process feeding input to unbuffer exits. Consider:
process1 | unbuffer -p process2 | process3
If process1 exits, process2 may not yet have finished. It is impossible for unbuffer to know long to wait for process2 and process2 may
not ever finish, for example, if it is a filter. For expediency, unbuffer simply exits when it encounters an EOF from either its input or
process2.
In order to have a version of unbuffer that worked in all situations, an oracle would be necessary. If you want an application-specific
solution, workarounds or hand-coded Expect may be more suitable. For example, the following example shows how to allow grep to finish pro-
cessing when the cat before it finishes first. Using cat to feed grep would never require unbuffer in real life. It is merely a place-
holder for some imaginary process that may or may not finish. Similarly, the final cat at the end of the pipeline is also a placeholder
for another process.
$ cat /tmp/abcdef.log | grep abc | cat
abcdef
xxxabc defxxx
$ cat /tmp/abcdef.log | unbuffer grep abc | cat
$ (cat /tmp/abcdef.log ; sleep 1) | unbuffer grep abc | cat
abcdef
xxxabc defxxx
$
BUGS
The man page is longer than the program.
SEE ALSO
"Exploring Expect: A Tcl-Based Toolkit for Automating Interactive Programs" by Don Libes, O'Reilly and Associates, January 1995.
AUTHOR
Don Libes, National Institute of Standards and Technology
1 June 1994 UNBUFFER(1)