04-26-2009
10 More Discussions You Might Find Interesting
1. Programming
My program only ouputs the correct magic square sum totals for the number 15.If I enter any odd number smaller than 15 my sum totals are incorrect. I have define "size" to 15. How or what do I change so that my program will output the magic square results for the odd numbers 1 through 15 without... (1 Reply)
Discussion started by: JJJ
1 Replies
2. Programming
Read the title: how do i do it? (4 Replies)
Discussion started by: Gekko
4 Replies
3. Programming
Hi,
Program A: uses pipe()
I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using:
* child
-> dup2(fd, STDOUT_FILENO);
-> execl("/path/PROGRAM B", "PROGRAM B", NULL);
* parent
-> char line;
-> read(fd, line, 100);
Question:
---------... (1 Reply)
Discussion started by: vvaidyan
1 Replies
4. UNIX for Dummies Questions & Answers
Hi,
Program A: uses pipe()
I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using:
* child
-> dup2(fd, STDOUT_FILENO);
-> execl("/path/PROGRAM B", "PROGRAM B", NULL);
* parent
-> char line;
-> read(fd, line, 100);
Question:
---------... (3 Replies)
Discussion started by: vvaidyan
3 Replies
5. Programming
Hi,
I wanted to know if i can write a program using switches and signals, etc to trace execution of other unix program which calls c program internally.
If yes how? If not with signals and switches then are there any other methods apart from debugging with gdb/dbx. (3 Replies)
Discussion started by: jiten_hegde
3 Replies
6. UNIX for Dummies Questions & Answers
Hi,
i want to write a script that executes a program (exec?) .
this program then requires a filename as input.
how do i give it this input in the script so the program will be complete run and close by the script.
e.g.
exec prog.exe
program then asks for filename
"enter filename:"... (1 Reply)
Discussion started by: tuathan
1 Replies
7. Programming
I wrote a simple program that generates a random word 10,000,000 times.
I wrote it in python, then in C++ and compared the two completion times. The python script was faster! Is that normal? Why would the python script be faster? I was under the impression that C++ was faster. What are some of... (2 Replies)
Discussion started by: cbreiny
2 Replies
8. Programming
Hi All,
Probably this is a repeated question. My knowledge in this is limited and i got confused on all those materials i got in google search.
We use #include <> to include a predefined library like stdio.h
i saw somewhere that #include "" includes a man made module(another C program). IS... (2 Replies)
Discussion started by: jisha
2 Replies
9. Homework & Coursework Questions
Long story short: I'm working inside of a Unix SSH under a bash shell. I have to code a C program that generates a random number. Then I have to call the compiled C program with a Perl program to run the C program 20 times and put all the generated random #s into a text file, then print that text... (1 Reply)
Discussion started by: jdkirby
1 Replies
10. Shell Programming and Scripting
I created a program, so a kid can practice there math on it. It dispenses varies math problems and the kid must input an answer. I also want it to grade the work they have done, but I can't find the best place for it to print out the grade.
I have:
if ( $response =~ m/^/ ) {
$user_wants_to_quit... (1 Reply)
Discussion started by: germany1517
1 Replies
LEARN ABOUT BSD
pthread_atfork
PTHREAD_ATFORK(3) Library Functions Manual PTHREAD_ATFORK(3)
NAME
pthread_atfork - register handlers to be called at fork(2) time
SYNOPSIS
#include <pthread.h>
int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void));
DESCRIPTION
pthread_atfork registers handler functions to be called just before and just after a new process is created with fork(2). The prepare han-
dler will be called from the parent process, just before the new process is created. The parent handler will be called from the parent
process, just before fork(2) returns. The child handler will be called from the child process, just before fork(2) returns.
One or several of the three handlers prepare, parent and child can be given as NULL, meaning that no handler needs to be called at the cor-
responding point.
pthread_atfork can be called several times to install several sets of handlers. At fork(2) time, the prepare handlers are called in LIFO
order (last added with pthread_atfork, first called before fork), while the parent and child handlers are called in FIFO order (first
added, first called).
To understand the purpose of pthread_atfork, recall that fork(2) duplicates the whole memory space, including mutexes in their current
locking state, but only the calling thread: other threads are not running in the child process. The mutexes are not usable after the fork
and must be initialized with pthread_mutex_init in the child process. This is a limitation of the current implementation and might or
might not be present in future versions.
RETURN VALUE
pthread_atfork returns 0 on success and a non-zero error code on error.
ERRORS
ENOMEM insufficient memory available to register the handlers.
AUTHOR
Xavier Leroy <Xavier.Leroy@inria.fr>
SEE ALSO
fork(2), pthread_mutex_lock(3), pthread_mutex_unlock(3).
LinuxThreads PTHREAD_ATFORK(3)