Initial import (2.0.2-6)2.0.2-6

1 files changed, 176 insertions, 0 deletions

diff --git a/reference/C/CONTRIB/OR_USING_C/b.1.c b/reference/C/CONTRIB/OR_USING_C/b.1.c
new file mode 100644
index 0000000..422b975
--- /dev/null
+++ b/reference/C/CONTRIB/OR_USING_C/b.1.c
@@ -0,0 +1,176 @@
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/file.h>
+#include <signal.h>
+#include <stdio.h>
+
+ptyopen(cmd, ifp, ofp)
+char *cmd;
+FILE **ifp, **ofp;
+{
+    int i;
+    char *args[16];
+    register int tty;
+    long ldisc, lmode;
+    register char *s, *t;
+    struct sgttyb sgttyb;
+    struct tchars tchars;
+    struct ltchars ltchars;
+    char ttybuf[16], ptybuf[16];
+
+    /*
+     * Split up the arguments in the command
+     * into an argv-like structure.
+     */
+    i = 0;
+    s = cmd;
+
+    while (*s) {
+        /*
+         * Skip white space.
+         */
+        while ((*s == ' ') || (*s == '\t'))
+            *s++ = NULL;
+
+        args[i++] = s;
+
+        /*
+         * Skip over this word to next white space.
+         */
+        while ((*s != NULL) && (*s != ' ') && (*s != '\t'))
+            s++;
+    }
+    args[i] = NULL;
+    /*
+     * Get a pseudo-tty.  We do this by cycling through all 
+     * the possible names.  The operating system will not 
+     * allow us to open a master which is already in use,
+     * so we simply go until the open succeeds.
+     */
+    for (s = "pqrs"; *s != NULL; s++) {
+        for (t = "0123456789abcdef"; *t != NULL; t++) {
+            sprintf(ptybuf, "/dev/pty%c%c", *s, *t);
+            if ((tty = open(ptybuf, O_RDWR)) >= 0)
+                goto out;
+        }
+    }
+out:
+    /*
+     * If s and t are NULL, we ran out of pseudo ttys 
+     * before we found one we can use.
+     */
+    if ((*s == NULL) && (*t == NULL))
+        return(-1);
+    /*
+     * Change "ptyXX" (master) to "ttyXX" (slave).
+     */
+    strcpy(ttybuf, ptybuf);
+    ttybuf[5] = 't';
+    /*
+     * Get the modes of the current terminal.  We
+     * will duplicate these on the pseudo terminal.
+     */
+    ioctl(0, TIOCGETD, &ldisc);
+    ioctl(0, TIOCLGET, &lmode);
+    ioctl(0, TIOCGETP, &sgttyb);
+    ioctl(0, TIOCGETC, &tchars);
+    ioctl(0, TIOCGLTC, &ltchars);
+    /*
+     * Fork a child process.
+     */
+    if ((i = fork()) < 0) {
+        close(tty);
+        return(-1);
+    }
+
+    /*
+     * In the child...
+     */
+    if (i == 0) {
+        /*
+         * Close all open files.
+         */
+        for (i = 0; i < NOFILE; i++)
+            close(i);
+
+        /*
+         * Clear the controlling tty.  This means
+         * that we will not have a controlling
+         * tty until we open another terminal
+         * device.
+         */
+        if ((i = open("/dev/tty", O_RDWR)) >= 0) {
+            ioctl(i, TIOCNOTTY, 0);
+            close(i);
+        }
+
+        /*
+         * Make our controlling tty the pseudo tty.
+         * This happens because we cleared our
+         * original controlling terminal above.
+         */
+        i = open(ttybuf, O_RDWR);
+
+        /*
+         * Set stdin, stdout, and stderr to be the
+         * pseudo terminal.
+         */
+        dup2(i, 0);
+        dup2(i, 1);
+        dup2(i, 2);
+
+        /*
+         * Set the pseudo terminal's tty modes to
+         * those of the original terminal.  We
+         * turn off ECHO and CBREAK modes, since
+         * we don't want characters "typed" to be
+         * printed.
+         */
+        sgttyb.sg_flags &= ~ECHO;
+        sgttyb.sg_flags &= ~CRMOD;
+
+        ioctl(0, TIOCSETD, &ldisc);
+        ioctl(0, TIOCLGET, &lmode);
+        ioctl(0, TIOCSETP, &sgttyb);
+        ioctl(0, TIOCSETC, &tchars);
+        ioctl(0, TIOCSLTC, &ltchars);
+
+        /*
+         * Set the process group of the process
+         * to be the process group of the
+         * terminal.
+         */
+        ioctl(0, TIOCGPGRP, &i);
+        setpgrp(0, i);
+
+        /*
+         * Now change the process group of the
+         * terminal and process to be the
+         * process id; this takes them out
+         * of the calling process's process
+         * group.
+         */
+        i = getpid();
+
+        ioctl(0, TIOCSPGRP, &i);
+        setpgrp(0, i);
+
+        /*
+         * Execute the program.
+         */
+        execv(*args, args);
+
+        exit(1);
+    }
+
+    /*
+     * Set up the input and output file pointers
+     * so that they can write and read the pseudo
+     * terminal.
+     */
+    *ifp = fdopen(tty, "w");
+    *ofp = fdopen(tty, "r");
+
+    return(0);
+}
+