The OpenNET Project / Index page

[ новости /+++ | форум | wiki | теги | ]

Интерактивная система просмотра системных руководств (man-ов)

 ТемаНаборКатегория 
 
 [Cписок руководств | Печать]

pipe (2)
  • pipe (2) ( Solaris man: Системные вызовы )
  • pipe (2) ( FreeBSD man: Системные вызовы )
  • pipe (2) ( Русские man: Системные вызовы )
  • >> pipe (2) ( Linux man: Системные вызовы )
  • pipe (3) ( POSIX man: Библиотечные вызовы )
  • pipe (7) ( Linux man: Макропакеты и соглашения )
  • pipe (8) ( Linux man: Команды системного администрирования )
  • Ключ pipe обнаружен в базе ключевых слов.
  •  

    NAME

    pipe, pipe2 - create pipe
     
    

    SYNOPSIS

    #include <unistd.h>
    
    int pipe(int pipefd[2]);
    
    #define _GNU_SOURCE
    #include <unistd.h>
    
    int pipe2(int pipefd[2], int flags);
    
     

    DESCRIPTION

    pipe() creates a pipe, a unidirectional data channel that can be used for interprocess communication. The array pipefd is used to return two file descriptors referring to the ends of the pipe. pipefd[0] refers to the read end of the pipe. pipefd[1] refers to the write end of the pipe. Data written to the write end of the pipe is buffered by the kernel until it is read from the read end of the pipe. For further details, see pipe(7).

    If flags is 0, then pipe2() is the same as pipe(). The following values can be bitwise ORed in flags to obtain different behavior:

    O_NONBLOCK
    Set the O_NONBLOCK file status flag on the two new open file descriptions. Using this flag saves extra calls to fcntl(2) to achieve the same result.
    O_CLOEXEC
    Set the close-on-exec (FD_CLOEXEC) flag on the two new file descriptors. See the description of the same flag in open(2) for reasons why this may be useful.
     

    RETURN VALUE

    On success, zero is returned. On error, -1 is returned, and errno is set appropriately.  

    ERRORS

    EFAULT
    pipefd is not valid.
    EINVAL
    (pipe2()) Invalid value in flags.
    EMFILE
    Too many file descriptors are in use by the process.
    ENFILE
    The system limit on the total number of open files has been reached.
     

    VERSIONS

    pipe2() was added to Linux in version 2.6.27; glibc support is available starting with version 2.9.  

    CONFORMING TO

    pipe(): POSIX.1-2001.

    pipe2() is Linux-specific.  

    EXAMPLE

    The following program creates a pipe, and then fork(2)s to create a child process; the child inherits a duplicate set of file descriptors that refer to the same pipe. After the fork(2), each process closes the descriptors that it doesn't need for the pipe (see pipe(7)). The parent then writes the string contained in the program's command-line argument to the pipe, and the child reads this string a byte at a time from the pipe and echoes it on standard output.
    
    #include <sys/wait.h>
    #include <assert.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <unistd.h>
    #include <string.h>
    
    int
    main(int argc, char *argv[])
    {
        int pipefd[2];
        pid_t cpid;
        char buf;
    
        assert(argc == 2);
    
        if (pipe(pipefd) == -1) {
            perror("pipe");
            exit(EXIT_FAILURE);
        }
    
        cpid = fork();
        if (cpid == -1) {
            perror("fork");
            exit(EXIT_FAILURE);
        }
    
        if (cpid == 0) {    /* Child reads from pipe */
            close(pipefd[1]);          /* Close unused write end */
    
            while (read(pipefd[0], &buf, 1) > 0)
                write(STDOUT_FILENO, &buf, 1);
    
            write(STDOUT_FILENO, "\n", 1);
            close(pipefd[0]);
            _exit(EXIT_SUCCESS);
    
        } else {            /* Parent writes argv[1] to pipe */
            close(pipefd[0]);          /* Close unused read end */
            write(pipefd[1], argv[1], strlen(argv[1]));
            close(pipefd[1]);          /* Reader will see EOF */
            wait(NULL);                /* Wait for child */
            exit(EXIT_SUCCESS);
        }
    }
    
     

    SEE ALSO

    fork(2), read(2), socketpair(2), write(2), popen(3), pipe(7)  

    COLOPHON

    This page is part of release 3.14 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.


     

    Index

    NAME
    SYNOPSIS
    DESCRIPTION
    RETURN VALUE
    ERRORS
    VERSIONS
    CONFORMING TO
    EXAMPLE
    SEE ALSO
    COLOPHON


    Поиск по тексту MAN-ов: 




    Спонсоры:
    Inferno Solutions
    Hosting by Hoster.ru
    Хостинг:

    Закладки на сайте
    Проследить за страницей
    Created 1996-2021 by Maxim Chirkov
    Добавить, Поддержать, Вебмастеру