main.c

unix环境高级编程的源代码

#include    <sys/types.h>
#include    <termios.h>
#ifndef    TIOCGWINSZ
#include    <sys/ioctl.h>    /* 44BSD requires this too */
#endif
#include    "ourhdr.h"

static void    set_noecho(int);    /* at the end of this file */
void        do_driver(char *);    /* in the file driver.c */
void        loop(int, int);        /* in the file loop.c */

int
main(int argc, char *argv[])
{
    int                fdm, c, ignoreeof, interactive, noecho, verbose;
    pid_t            pid;
    char            *driver, slave_name[20];
    struct termios    orig_termios;
    struct winsize    size;

    interactive = isatty(STDIN_FILENO);
    ignoreeof = 0;
    noecho = 0;
    verbose = 0;
    driver = NULL;

    opterr = 0;        /* don't want getopt() writing to stderr */
    while ( (c = getopt(argc, argv, "d:einv")) != EOF) {
        switch (c) {
        case 'd':        /* driver for stdin/stdout */
            driver = optarg;
            break;

        case 'e':        /* noecho for slave pty's line discipline */
            noecho = 1;
            break;

        case 'i':        /* ignore EOF on standard input */
            ignoreeof = 1;
            break;
        case 'n':        /* not interactive */
            interactive = 0;
            break;

        case 'v':        /* verbose */
            verbose = 1;
            break;

        case '?':
            err_quit("unrecognized option: -%c", optopt);
        }
    }
    if (optind >= argc)
        err_quit("usage: pty [ -d driver -einv ] program [ arg ... ]");

    if (interactive) {    /* fetch current termios and window size */
        if (tcgetattr(STDIN_FILENO, &orig_termios) < 0)
            err_sys("tcgetattr error on stdin");
        if (ioctl(STDIN_FILENO, TIOCGWINSZ, (char *) &size) < 0)
            err_sys("TIOCGWINSZ error");
        pid = pty_fork(&fdm, slave_name, &orig_termios, &size);

    } else
        pid = pty_fork(&fdm, slave_name, NULL, NULL);

    if (pid < 0)
        err_sys("fork error");

    else if (pid == 0) {        /* child */
        if (noecho)
            set_noecho(STDIN_FILENO);    /* stdin is slave pty */

        if (execvp(argv[optind], &argv[optind]) < 0)
            err_sys("can't execute: %s", argv[optind]);
    }

    if (verbose) {
        fprintf(stderr, "slave name = %s\n", slave_name);
        if (driver != NULL)
            fprintf(stderr, "driver = %s\n", driver);
    }

    if (interactive && driver == NULL) {
        if (tty_raw(STDIN_FILENO) < 0)    /* user's tty to raw mode */
            err_sys("tty_raw error");
        if (atexit(tty_atexit) < 0)        /* reset user's tty on exit */
            err_sys("atexit error");
    }

    if (driver)
        do_driver(driver);    /* changes our stdin/stdout */

    loop(fdm, ignoreeof);    /* copies stdin -> ptym, ptym -> stdout */

    exit(0);
}
static void
set_noecho(int fd)        /* turn off echo (for slave pty) */
{
    struct termios    stermios;

    if (tcgetattr(fd, &stermios) < 0)
        err_sys("tcgetattr error");

    stermios.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
    stermios.c_oflag &= ~(ONLCR);
            /* also turn off NL to CR/NL mapping on output */

    if (tcsetattr(fd, TCSANOW, &stermios) < 0)
        err_sys("tcsetattr error");
}