253 lines
5.8 KiB
C
Executable file
253 lines
5.8 KiB
C
Executable file
/* modem - Put modem into DIALIN or DIALOUT mode. Author: F. van Kempen */
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/* Exit: 0 OK, suspended/restarted GETTY
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* 1 UNIX error
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* 2 Process busy
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* Version: 1.3 12/30/89
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*
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* Author: F. van Kempen, MicroWalt Corporation
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*
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* All fancy stuff removed, see getty.c. Kees J. Bot.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/wait.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <string.h>
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#include <unistd.h>
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#include <utmp.h>
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#include <errno.h>
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#include <minix/paths.h>
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char PATH_UTMP[] = _PATH_UTMP; /* current logins */
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_PROTOTYPE(void usage , (void));
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_PROTOTYPE(int main , (int argc , char *argv []));
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_PROTOTYPE(void sendcodes , (char *tty, char *codes));
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void usage()
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{
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fprintf(stderr,
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"Usage: modem [-sio] [-I in-codes] [-O out-codes] line [command args ...]\n");
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exit(1);
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}
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main(argc, argv)
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int argc;
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char *argv[];
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{
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struct utmp entry;
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char devtty[1024], *tty;
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char **command;
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int ex_code = 0;
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int fd, i, slot, getty;
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struct stat st;
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enum { TOGGLE, DIALIN, DIALOUT } mode= TOGGLE;
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int silent = 0;
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_PROTOTYPE(void (*hsig), (int));
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_PROTOTYPE(void (*isig), (int));
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_PROTOTYPE(void (*qsig), (int));
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_PROTOTYPE(void (*tsig), (int));
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pid_t pid;
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int r, status;
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uid_t uid = getuid();
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gid_t gid = getgid();
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char *in_codes, *out_codes;
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i = 1;
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while (i < argc && argv[i][0] == '-') {
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char *opt = argv[i++] + 1;
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if (opt[0] == '-' && opt[1] == 0) break;
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while (*opt != 0) {
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switch (*opt++) {
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case 's': /* silent mode */
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silent = 1;
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break;
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case 'i': /* DIAL-IN mode: suspend GETTY */
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mode = DIALIN;
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break;
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case 'o': /* DIAL-OUT mode: restart GETTY */
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mode = DIALOUT;
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break;
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case 'I': /* code to switch modem to dial-in */
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if (*opt == 0) {
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if (i == argc) usage();
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opt = argv[i++];
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}
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in_codes = opt;
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opt = "";
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break;
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case 'O': /* code to switch modem to dial-out */
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if (*opt == 0) {
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if (i == argc) usage();
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opt = argv[i++];
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}
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out_codes = opt;
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opt = "";
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break;
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default:
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usage();
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}
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}
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}
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if (i == argc) usage();
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tty = argv[i++]; /* Modem line */
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if (mode != TOGGLE && i != argc) usage();
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command = argv + i; /* Command to execute (if any). */
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if (strchr(tty, '/') == NULL) {
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strcpy(devtty, "/dev/");
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strncat(devtty, tty, 1024 - 6);
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tty = devtty;
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}
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if (stat(tty, &st) < 0) {
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fprintf(stderr, "modem: %s: %s\n", tty, strerror(errno));
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exit(1);
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}
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if (!S_ISCHR(st.st_mode)) {
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fprintf(stderr, "%s is not a tty\n", tty);
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exit(1);
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}
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/* Find the utmp slot number for the line. */
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if ((fd= open(tty, O_RDONLY)) < 0 || (slot= fttyslot(fd)) == 0) {
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fprintf(stderr, "modem: %s: %s\n", tty, strerror(errno));
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exit(1);
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}
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close(fd);
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/* Read the UTMP file to find out the PID and STATUS of the GETTY. */
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entry.ut_type= 0;
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if ((fd = open(PATH_UTMP, O_RDONLY)) < 0
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|| lseek(fd, (off_t) slot * sizeof(entry), SEEK_SET) < 0
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|| read(fd, &entry, sizeof(entry)) < 0
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) {
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fprintf(stderr, "modem: cannot read UTMP !\n");
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exit(1);
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}
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close(fd);
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hsig= signal(SIGHUP, SIG_IGN);
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isig= signal(SIGINT, SIG_IGN);
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qsig= signal(SIGQUIT, SIG_IGN);
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tsig= signal(SIGTERM, SIG_IGN);
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/* Process the terminal entry if we got one. */
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switch (entry.ut_type) {
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case LOGIN_PROCESS: /* getty waiting for a call */
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getty = 1;
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break;
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case USER_PROCESS: /* login or user-shell */
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if (!silent) fprintf(stderr, "modem: line is busy.\n");
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exit(2);
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break;
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default:
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getty = 0;
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}
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for (i = (mode == TOGGLE) ? 0 : 1; i < 2; i++) {
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/* Now perform the desired action (DIALIN or DIALOUT). */
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switch (mode) {
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case DIALOUT:
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case TOGGLE:
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if (getty) kill(entry.ut_pid, SIGUSR1); /* suspend getty */
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chown(tty, uid, st.st_gid); /* give line to user */
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chmod(tty, 0600);
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if (out_codes != NULL) sendcodes(tty, out_codes);
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if (!silent) printf("modem on %s set for dialout.\n", tty);
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break;
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case DIALIN:
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if (in_codes != NULL) sendcodes(tty, in_codes);
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chown(tty, 0, st.st_gid); /* revoke access */
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chmod(tty, 0600);
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if (getty) kill(entry.ut_pid, SIGUSR2); /* restart getty */
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if (!silent) printf("modem on %s set for dialin.\n", tty);
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}
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if (mode == TOGGLE) {
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/* Start the command to run */
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pid_t pid;
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int status;
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switch ((pid = fork())) {
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case -1:
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fprintf(stderr, "modem: fork(): %s\n", strerror(errno));
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ex_code= 1;
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break;
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case 0:
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setgid(gid);
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setuid(uid);
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(void) signal(SIGHUP, hsig);
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(void) signal(SIGINT, isig);
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(void) signal(SIGQUIT, qsig);
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(void) signal(SIGTERM, tsig);
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execvp(command[0], command);
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fprintf(stderr, "modem: %s: %s\n",
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command[0], strerror(errno));
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_exit(127);
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default:
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while ((r= wait(&status)) != pid) {
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if (r == -1 && errno != EINTR) break;
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}
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if (r == -1 || status != 0) ex_code = 1;
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}
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mode = DIALIN;
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}
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}
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exit(ex_code);
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}
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void sendcodes(tty, codes)
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char *tty, *codes;
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{
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int fd;
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int c;
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char buf[1024], *bp = buf;
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if ((fd = open(tty, O_RDWR|O_NONBLOCK)) < 0) {
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fprintf(stderr, "modem: can't send codes to %s: %s\n",
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tty, strerror(errno));
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return;
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}
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while ((c = *codes++) != 0) {
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fprintf(stderr, "%d\n", __LINE__);
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if (c == '\\') {
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if ((c = *codes++) == 0) break;
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if (c == 'r') c= '\r';
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if (c == 'n') c= '\n';
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}
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*bp++ = c;
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if (bp == buf + sizeof(buf) || c == '\r' || c == '\n') {
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fprintf(stderr, "%d\n", __LINE__);
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write(fd, buf, bp - buf);
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fprintf(stderr, "%d\n", __LINE__);
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do {sleep(1);
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fprintf(stderr, "%d\n", __LINE__);
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fprintf(stderr, "%d\n", read(fd, buf, sizeof(buf)));
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}while (read(fd, buf, sizeof(buf)) > 0);
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fprintf(stderr, "%d\n", __LINE__);
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bp = buf;
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}
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}
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if (bp > buf) {
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fprintf(stderr, "%d\n", __LINE__);
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write(fd, buf, bp - buf);
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fprintf(stderr, "%d\n", __LINE__);
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do sleep(1); while (read(fd, buf, sizeof(buf)) > 0);
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fprintf(stderr, "%d\n", __LINE__);
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}
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close(fd);
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}
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