fork

问题 I need to write my pipestream. My program should get names of another programs and call them, first program should read from stdin second from output of the first an so on. Last program print the result in stdout. The problem is it doesn't work. When I call this program to two another simple programs (they both are to read x and print 2*x while it can read), and give it some data I suppose that I should get result immediately, but I don't. What is more when I give it end of file it doesn't

问题 This code is supposed to try and start a server process and return. If the port was taken, it should say "couldn't bind to that port" and return. If the server started, it should print "Bound to port 51231" and return. But it does not return. import socket from multiprocessing import Process def serverMainLoop(s,t): s.listen(5) while 1: pass # server goes here host = '' port = 51231 so = socket.socket(socket.AF_INET, socket.SOCK_STREAM) try: so.bind((host,port)) print "Bound to port %i"%port

问题 Trying to implement a shell, mainly piping. I've written this test case which I expect to simply pipe ls to wc...it definitely doesn't work as expected. It prints ls to the terminal then prints memory exhausted. I'm very lost in how to fix this and get it to work. find_path works in all of my tests. Edit - I have to use execv for the project, its a class thing, but I've tried it with execvp just in case and it does the exact same thing. Also this is just an example, a test to see why it does

问题 I have a 3 projects I'd like to fork. They're all related to each other - changing one will likely require a change to another. Because they're all related, I'd like to create 1 repository for the forks, while maintaining the ability to pull down updates from each original. How would I setup my git repository? These are preliminary thoughts so I wouldn't be surprised if this is crazy/stupid. Is it? 回答1: You can always use " git remote add <name> <url> " to add more repositories as source. 回答2

问题 I've been dabbling with Mercurial for a short while now, and I've now set up several projects on BitBucket, one forking off of the other. I've been able to make changes to each repo with no problem, but one thing I can't figure out, is how to keep the fork up-to-date with changes from the parent repo? After I've forked a repo, I only see the commits from that repo up to X revision, after which point I only see the fork's own commits, no new parent commits. I'm pretty certain that during my

问题 I'm trying to pass a pipe to another process, which I create with execv. This is my code so far, but it doesn't work. I've looked everywhere for information, but I can't find anything specifically about passing a pipe vie exec. Any help is appreciated. Thanks int fd[2]; pipe(fd); char passwrite[1]; sprintf(passwrite, "%d", fd[0]); char arg[1]; arg[1]=passwrite; int x; x=fork(); if (x==0) { execv("NewProg",arg); } 回答1: There are a couple of potential problems with your code, even before you

问题 i am using fedora 15 with posix, and i want to fork my child processes in a new terminal window where i can interact only with the child process while the parent remain int he original terminal. I do not want to exec because that would require me to re arrange all of my code which doesnt seem fesaible at this moment as i have to present my project day after tomorrow.is it possible?how? i have tried forkpty but it gives me a compilation error. 回答1: Have a look to man screen . I think it can be

问题 I am trying to find the syntax that will let me redirect standard input output toward a named pipe after using the mkfifo() function and creating a child process using fork. Which man page should I be looking at for the syntax? Thanks, Aaron 回答1: Various sections of man page can serve your various purposes. Generally, Section 1 contain syntax for executable programs or shell command . man mkfifo Section 3 contain syntax for Library call ( used in c programs). man 3 mkfifo Edit: I think i

问题 The code below will spawn as many children as possible. Themselves won't fork further, and will become zombies once the parent process exits. How many children processes will the parent process spawn ? int main(int argc, char *arg[]) { while(fork() > 0); } 回答1: The number of child processes can be limited with setrlimit(2) using RLIMIT_NPROC . Notice that fork(2) can fail for several reasons. You could use bash builtin ulimit to set that limit. You can use getrlimit (or parse /proc/self

问题 I would like to run a separate process in Perl (a command line PHP script). I would like to capture this processes output AND return code. Optionally I would like to be able to terminate the process and move on if the process takes longer than N seconds. What should I look into? 回答1: You can try IPC::Run. IPC::Run - system() and background procs w/ piping, redirs, ptys (Unix, Win32) 回答2: use IPC::System::Simple qw/EXIT_ANY $EXITVAL capture/; my $output = capture(EXIT_ANY, 'some command');