ptyopen.c

unix环境高级编程的源代码

#include    <sys/types.h>
#include    <sys/stat.h>
#include    <errno.h>
#include    <fcntl.h>
#include    <stropts.h>
#include    "ourhdr.h"

extern char    *ptsname(int);    /* prototype not in any system header */

int
ptym_open(char *pts_name)
{
    char    *ptr;
    int        fdm;

    strcpy(pts_name, "/dev/ptmx");    /* in case open fails */
    if ( (fdm = open(pts_name, O_RDWR)) < 0)
        return(-1);

    if (grantpt(fdm) < 0) {        /* grant access to slave */
        close(fdm);
        return(-2);
    }
    if (unlockpt(fdm) < 0) {    /* clear slave's lock flag */
        close(fdm);
        return(-3);
    }
    if ( (ptr = ptsname(fdm)) == NULL) {    /* get slave's name */
        close(fdm);
        return(-4);
    }

    strcpy(pts_name, ptr);    /* return name of slave */
    return(fdm);            /* return fd of master */
}
int
ptys_open(int fdm, char *pts_name)
{
    int        fds;

            /* following should allocate controlling terminal */
    if ( (fds = open(pts_name, O_RDWR)) < 0) {
        close(fdm);
        return(-5);
    }
    if (ioctl(fds, I_PUSH, "ptem") < 0) {
        close(fdm);
        close(fds);
        return(-6);
    }
    if (ioctl(fds, I_PUSH, "ldterm") < 0) {
        close(fdm);
        close(fds);
        return(-7);
    }
    if (ioctl(fds, I_PUSH, "ttcompat") < 0) {
        close(fdm);
        close(fds);
        return(-8);
    }

    return(fds);
}