espo@bpa.UUCP (11/23/83)
Here's a nifty little program(s) to display the date & time of day on the screen of your VT100 terminal on a real-time basis. Although I've written it for a VT100, I'm sure those of you who have different terminals could modify it. The only thing that's required, is that the terminal has a cursor save function within it's command repertoire. The swc.c program included is use to switch the clock display on/off for those times when you don't want the display, but keeps the clock running until switched back on. Bob Esposito....bpa!espo /* **************************************************************************** ** ** program = vtclock.c ** ** author = R.J. Esposito ** ** Vtclock provides a visual clock display every minute on ** a real-time basis. The display is visable in the lower ** right-hand corner (row 24, col 56-80) of the screen. ** Vtclock could be modified to perform on other video ** terminals, provided they incorporate the cursor save ** function within their command repertoire. ** ** Vtclock should be called from the user's .profile for ** conveinence, but could be called from the shell. ** It should be run as a backround process, since cursor ** saving is done prior to clock display. ** ** An interface program 'swc.c' is used to switch the display ** on/off depending on it's previous state. Vtclock saves it's ** pid in the user's home directory in '.clock_pid'. Swc reads ** this file to send the SIGUSR1 (16) signal to vtclock for ** display switching. This file is removed when vtclock dies ** (SIGHUP). ** ** NOTE: Some strange things may occur when emacs is used in ** conjunction with vtclock. It may be wise to turn off ** the display (swc) prior to entering emacs, and then ** turning it back on (swc) after completion. If you're ** a die-hard (like me!) just use the ^L to re-draw the ** display. ** **************************************************************************** */ #include <stdio.h> #include <time.h> #include <sys/signal.h> #define SCROLL "\33[0;23r" /* set the scroll region (0 to 23) */ #define WINDOW "\33[0m\33[24;56f\33[7m \33[24;59f" #define SAVE "7" /* save cursor = ESC7 */ /* This MUST be typed-in from keyboard */ #define RESTORE "\338" /* restore cursor */ #define CLWIN "\33[0m\33[24;56f " #define ATT_OFF "\33[0m" struct tm *localtime(), *tp; char *asctime(); char *getenv(); char *strcpy(), *strcat(); char pid_file[100]; long time(), tloc; unsigned sleep(); int (*signal())(); int die(), on_off(), pm; int is_on = 1; FILE *fp; main() { unsigned sec_diff; setbuf(stdout, (char *)0); (void )strcpy(pid_file, getenv("HOME")); (void )strcat(pid_file, "/.clock_pid"); if((fp=fopen(pid_file, "w")) == NULL) { (void )puts("can't open clocl_pid"); exit(1); } (void )fprintf(fp, "%d\n", getpid()); (void )fclose(fp); (void )signal(SIGHUP, die); tloc = time ((long *)0); tp = localtime(&tloc); fixtime(tp->tm_hour); (void )printf("%s%s%16.16s", SAVE, WINDOW, asctime(tp)); if (pm) (void )fputs(" PM", stdout); else (void )fputs(" AM", stdout); (void )printf("%s%s%s", SCROLL, ATT_OFF, RESTORE); (void )signal(SIGUSR1, on_off); for (;;) { /* forever loop until hung-up */ tp = localtime(&tloc); sec_diff = 60 - tp->tm_sec; (void )sleep(sec_diff); tloc = time((long *)0); tp = localtime(&tloc); fixtime(tp->tm_hour); if (is_on) { if (tp->tm_min == 00) /* hourly chime */ (void )fputs("\7\7", stdout); (void )printf("%s%s%16.16s", SAVE, WINDOW, asctime(tp)); if (pm) (void )fputs(" PM", stdout); else (void )fputs(" AM", stdout); (void )printf("%s%s%s", SCROLL, ATT_OFF, RESTORE); } } } die() /* enter here when hung-up */ { (void )unlink(pid_file); exit(0); } on_off() /* routine used by swc to switch display on/off */ { if (is_on) { is_on = 0; (void )printf("%s%s\33[0;24r%s", SAVE, CLWIN, RESTORE); } else is_on = 1; (void )signal(SIGUSR1, on_off); } fixtime(hour) int hour; { switch(hour) { /* correct for AM/PM */ case 0: tp->tm_hour = 12; pm = 0; break; case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: pm = 0; break; case 12: pm = 1; break; case 13: case 14: case 15: case 16: case 17: case 18: case 19: case 20: case 21: case 22: case 23: tp->tm_hour -= 12; pm = 1; break; } } /* **************************************************************************** ** ** program = swc.c ** ** author = R.J. Esposito ** ** Swc is an interface to vtclock - it switches the display on/off ** depending on it's previous state. ** **************************************************************************** */ #include <stdio.h> FILE *fp; char pid_file[100]; char *strcpy(), *strcat(); char *getenv(); main() { char *pid; (void )strcpy(pid_file, getenv("HOME")); (void )strcat(pid_file, "/.clock_pid"); if((fp=fopen(pid_file, "r")) == NULL) exit(1);; pid = fgets(pid_file, 100, fp); (void )kill (atoi(pid), 16); /* send SIGUSR1 to vtclock */ (void )fclose(fp); }