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annotate ptyhelper.c @ 85:4303d94d87a2

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rlgwebd.js: Unlink control socket at startup. Unlinking at shutdown doesn't work because at that time, the process is chroot'ed and unprivileged.
author John "Elwin" Edwards <elwin@sdf.org>
date Sun, 08 Jul 2012 17:49:43 -0700
parents 9bef0941c6dd
children
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1
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1 /*
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2 * ptyhelper: a utility that runs a command in a pseudoterm and then streams
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3 * stdio to/from it. Intended to get around the node.js loss of C/UNIX
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4 * functionality.
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5 * Remember to compile with -lutil.
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6 */
0
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7 #include <stdio.h>
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8 #include <stdlib.h>
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9 #include <unistd.h>
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10 #include <signal.h>
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11 #include <pty.h>
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12 #include <utmp.h>
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13 #include <sys/types.h>
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14 #include <sys/wait.h>
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15 #include <sys/select.h>
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16 #include <termios.h>
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17
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18 int got_sighup = 0;
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19
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20 void handle_HUP(int signum) {
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21 if (signum == SIGHUP)
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22 got_sighup = 1;
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23 return;
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24 }
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25
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26 int main(int argc, char *argv[]) {
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27
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28 int ptymaster, ptyslave; /* File descriptors */
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29 int child;
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30 int status, selstatus;
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31 int w = 80, h = 24, t;
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32 struct sigaction sighup_act;
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33 fd_set readset;
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34 struct timeval select_time;
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35 char buf[4096];
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36 int nread;
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37 char *penv, *ptmp;
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38 #if 0
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39 struct termios ptysettings;
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40 #endif
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41 struct winsize ptysize;
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42
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43 if (argc == 1) {
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44 fprintf(stderr, "No command given.\n");
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45 exit(1);
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46 }
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47
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48 /* Set up the signal handler. */
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49 sighup_act.sa_handler = &handle_HUP;
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50 sighup_act.sa_flags = SA_RESTART;
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51 sigaction(SIGHUP, &sighup_act, NULL);
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52
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53 /* Check the environment for configuration options. */
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54 penv = getenv("PTYHELPER");
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55 if (penv != NULL) {
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56 t = strtol(penv, &ptmp, 10);
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57 if (t > 0 && t < 256)
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58 h = t;
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59 if (*ptmp != '\0') {
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60 penv = ptmp + 1;
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61 t = strtol(penv, &ptmp, 10);
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62 if (t > 0 && t < 256)
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63 w = t;
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64 }
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65 }
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66 /* Set up the size. */
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67 ptysize.ws_row = h;
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68 ptysize.ws_col = w;
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69
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70 /* Open a pty */
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71 if (openpty(&ptymaster, &ptyslave, NULL, NULL, &ptysize)) {
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72 return 1;
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73 }
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74 #if 0
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75 /* Put it into raw mode. */
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76 tcgetattr(ptyslave, &ptysettings);
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77 cfmakeraw(&ptysettings);
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78 tcsetattr(ptyslave, TCSANOW, &ptysettings);
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79 #endif
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80
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81 /* Start the child */
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82 /* forkpty() might be more convenient. */
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83 if (!(child = fork())) {
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84 /* Child process */
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85 login_tty(ptyslave);
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86 close(ptymaster);
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87 execvp(argv[1], argv + 1);
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88 perror("execvp() failed");