mdw@git.distorted.org.uk Git - xtoys/blob - xwait.c

   1 /* -*-c-*-
   2  *
   3  * $Id: xwait.c,v 1.8 1999/08/20 07:29:55 mdw Exp $
   4  *
   5  * Wait until prodded by another X client
   6  *
   7  * (c) 1998 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the Edgeware X tools collection.
  13  *
  14  * X tools is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * X tools is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with X tools; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: xwait.c,v $
  32  * Revision 1.8  1999/08/20 07:29:55  mdw
  33  * New command line syntax, and new atom protocol.  Wait for multiple
  34  * properties and listen for multiple (or all) values.
  35  *
  36  * Revision 1.7  1999/06/19 23:42:37  mdw
  37  * Improve signal handling.
  38  *
  39  * Revision 1.6  1998/12/11 09:50:07  mdw
  40  * Minor modifications to work with mLib and mgLib.
  41  *
  42  * Revision 1.5  1998/11/30 22:36:53  mdw
  43  * Tidy up tabbing in help texts very slightly.
  44  *
  45  * Revision 1.4  1998/11/21 22:41:19  mdw
  46  * Reap children which die before I get my signal handler installed.
  47  *
  48  * Revision 1.3  1998/11/21 22:30:27  mdw
  49  * Support GNU-style long options throughout, and introduce proper help
  50  * text to all programs.  Update manual pages to match.
  51  *
  52  * Revision 1.2  1998/11/18 21:25:06  mdw
  53  * Reap dead children as they arrive.  The previous shell may have
  54  * carelessly left them behind.
  55  *
  56  * Revision 1.1  1998/11/16 23:00:49  mdw
  57  * Initial versions.
  58  *
  59  */
  60
  61 /*----- Header files ------------------------------------------------------*/
  62
  63 #include <errno.h>
  64 #include <signal.h>
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68
  69 #include <sys/types.h>
  70 #include <sys/wait.h>
  71 #include <unistd.h>
  72
  73 #include <X11/Xlib.h>
  74 #include <X11/Xutil.h>
  75
  76 #include <mLib/mdwopt.h>
  77 #include <mLib/quis.h>
  78 #include <mLib/report.h>
  79 #include <mLib/sub.h>
  80
  81 #include "xatom.h"
  82 #include "xwait.h"
  83
  84 /*----- Data structures ---------------------------------------------------*/
  85
  86 typedef struct xwait_msg {
  87   struct xwait_msg *next;               /* Next message in the list */
  88   Atom a;                               /* The message atom */
  89 } xwait_msg;
  90
  91 typedef struct xwait_atom {
  92   struct xwait_atom *next;              /* Next atom in the list */
  93   Atom a;                               /* The actual atom */
  94   xwait_msg *m;                         /* List of interesting messages */
  95 } xwait_atom;
  96
  97 /*----- Static variables --------------------------------------------------*/
  98
  99 static xwait_atom *atoms = 0;
 100 static Display *dpy;
 101
 102 /*----- Main code ---------------------------------------------------------*/
 103
 104 /* --- @sigchld@ --- */
 105
 106 static void sigchld(int sig)
 107 {
 108   int e = errno;
 109   while (waitpid(-1, 0, WNOHANG) > 0)
 110     ;
 111   errno = e;
 112 }
 113
 114 /* --- @opendisplay@ --- */
 115
 116 static void opendisplay(const char *d)
 117 {
 118   if (dpy)
 119     return;
 120   if ((dpy = XOpenDisplay(d)) == 0)
 121     die(EXIT_FAILURE, "couldn't open display");
 122 }
 123
 124 /* --- @addatom@ --- */
 125
 126 static xwait_atom *addatom(const char *a)
 127 {
 128   xwait_atom *xa = CREATE(xwait_atom);
 129   opendisplay(0);
 130   xa->next = atoms;
 131   xa->a = XInternAtom(dpy, a, False);
 132   xa->m = 0;
 133   atoms = xa;
 134   return (xa);
 135 }
 136
 137 /* --- @addmsg@ --- */
 138
 139 static void addmsg(xwait_atom *xa, const char *a)
 140 {
 141   xwait_msg *xm = CREATE(xwait_msg);
 142   opendisplay(0);
 143   xm->next = xa->m;
 144   xm->a = XInternAtom(dpy, a, False);
 145   xa->m = xm;
 146 }
 147
 148 /* --- @tidy@ --- */
 149
 150 static void tidy(int sig)
 151 {
 152   int i;
 153   int nsc = ScreenCount(dpy);
 154   xwait_atom *xa;
 155
 156   for (i = 0; i < nsc; i++) {
 157     for (xa = atoms; xa; xa = xa->next)
 158       XDeleteProperty(dpy, RootWindow(dpy, i), xa->a);
 159   }
 160   XCloseDisplay(dpy);
 161   exit(0);
 162 }
 163
 164 /* --- @main@ --- */
 165
 166 static void version(FILE *fp)
 167 {
 168   fprintf(fp, "%s (xtoys version " VERSION ")\n", QUIS);
 169 }
 170
 171 static void usage(FILE *fp)
 172 {
 173   fprintf(fp, "Usage: %s [-f] [-d DISPLAY] [ATOM:MSG,MSG]...\n", QUIS);
 174 }
 175
 176 int main(int argc, char *argv[])
 177 {
 178   Atom a;
 179   XEvent ev;
 180   unsigned f = 0;
 181   xwait_atom *xa = 0;
 182   xwait_msg *xm = 0;
 183
 184   enum {
 185     f_force = 1
 186   };
 187
 188   /* --- Initialize mLib --- */
 189
 190   ego(argv[0]);
 191   sub_init();
 192
 193   /* --- Parse options --- */
 194
 195   for (;;) {
 196     static struct option opt[] = {
 197       { "help",         0,                      0,      'h' },
 198       { "usage",        0,                      0,      'u' },
 199       { "version",      0,                      0,      'v' },
 200       { "display",      OPTF_ARGREQ,            0,      'd' },
 201       { "atom",         OPTF_ARGREQ,            0,      'a' },
 202       { "msg",          OPTF_ARGREQ,            0,      'm' },
 203       { "force",        0,                      0,      'f' },
 204       { 0,              0,                      0,      0 }
 205     };
 206
 207     int i = mdwopt(argc, argv, "d:a:m:f", opt, 0, 0, 0);
 208     if (i < 0)
 209       break;
 210     switch (i) {
 211       case 'h':
 212         version(stdout);
 213         fputs("\n", stdout);
 214         usage(stdout);
 215         fputs(
 216 "\n"
 217 "Waits until signalled by `xtell' or `xshutdown'.  Specifically, waits\n"
 218 "until a property with name ATOM is written to the root window with\n"
 219 "contents MSG.\n"
 220 "\n"
 221 "Options:\n"
 222 "\n"
 223 "-h, --help             Display this help text\n"
 224 "-u, --usage            Display a short usage summary\n"
 225 "-v, --version          Display the program's version number\n"
 226 "\n"
 227 "-d, --display=DISPLAY  Choose X display to connect to\n"
 228 "-f, --force            Run even if this property is waited for by another\n"
 229 "                       process\n"
 230 "-a, --atom=ATOM\t      Choose property name to listen for [deprecated]\n"
 231 "-m, --msg=MSG          Choose value of property to wait for [deprecated]\n",
 232           stdout);
 233         exit(0);
 234         break;
 235       case 'u':
 236         usage(stdout);
 237         exit(0);
 238         break;
 239       case 'v':
 240         version(stdout);
 241         exit(0);
 242         break;
 243
 244       case 'd':
 245         opendisplay(optarg);
 246         break;
 247       case 'a':
 248         xa = addatom(optarg);
 249         break;
 250       case 'm':
 251         if (!xa)
 252           die(EXIT_FAILURE, "no atom currently defined");
 253         addmsg(xa, optarg);
 254         break;
 255       case 'f':
 256         f |= f_force;
 257         break;
 258       default:
 259         usage(stderr);
 260         exit(EXIT_FAILURE);
 261         break;
 262     }
 263   }
 264
 265   /* --- Grind through remaining arguments in the new syntax --- */
 266
 267   while (optind < argc) {
 268     char *p = strtok(argv[optind++], ":");
 269     if (!p)
 270       continue;
 271     xa = addatom(p);
 272     while ((p = strtok(0, ",")) != 0)
 273       addmsg(xa, p);
 274   }
 275
 276   /* --- If there's nothing set, put in some defaults --- */
 277
 278   if (!atoms) {
 279     xa = addatom(XWAIT_DIE);
 280     addmsg(xa, XWAIT_DIE_MSG);
 281   }
 282
 283   /* --- Attach the atoms to the screens --- */
 284
 285   {
 286     int i;
 287     Atom ready = XInternAtom(dpy, "XWAIT_READY", False);
 288     int nsc = ScreenCount(dpy);
 289
 290     /* --- First pass: make sure there's not a process already here --- */
 291
 292     if ((f & f_force) == 0) {
 293       for (i = 0; i < nsc; i++) {
 294         for (xa = atoms; xa; xa = xa->next) {
 295           if (xatom_get(dpy, RootWindow(dpy, i), xa->a) != None)
 296             die(EXIT_FAILURE, "already waiting for `%s'");
 297         }
 298       }
 299     }
 300
 301     /* --- Second pass: set up listening to the property --- */
 302
 303     for (i = 0; i < nsc; i++) {
 304       for (xa = atoms; xa; xa = xa->next)
 305         xatom_set(dpy, RootWindow(dpy, i), xa->a, ready);
 306       XSelectInput(dpy, RootWindow(dpy, i), PropertyChangeMask);
 307     }
 308   }
 309
 310   /* --- Set up a handler when children die --- *
 311    *
 312    * I don't fork any children?  Why is this useful?  Because I've been
 313    * execed from a shell which started lots of background processes, and
 314    * they'll zombie themselves otherwise.
 315    */
 316
 317   {
 318     struct sigaction sa;
 319
 320     sa.sa_handler = sigchld;
 321     sigemptyset(&sa.sa_mask);
 322     sigaddset(&sa.sa_mask, SIGCHLD);
 323     sa.sa_flags = SA_NOCLDSTOP;
 324 #ifdef SA_RESTART
 325     sa.sa_flags |= SA_RESTART;
 326 #endif
 327     sigaction(SIGCHLD, &sa, 0);
 328   }
 329
 330   /* --- Now reap any which have been waiting around so far --- */
 331
 332   {
 333     sigset_t ss, oss;
 334
 335     sigemptyset(&ss);
 336     sigaddset(&ss, SIGCHLD);
 337     sigprocmask(SIG_BLOCK, &ss, &oss);
 338     sigchld(SIGCHLD);
 339     sigprocmask(SIG_SETMASK, &oss, 0);
 340   }
 341
 342   signal(SIGINT, tidy);
 343   signal(SIGTERM, tidy);
 344
 345   /* --- Now wait for an event --- */
 346
 347   for (;;) {
 348     XNextEvent(dpy, &ev);
 349     switch (ev.type) {
 350       case PropertyNotify:
 351         for (xa = atoms; xa; xa = xa->next) {
 352           if (ev.xproperty.atom != xa->a)
 353             continue;
 354           a = xatom_get(dpy, ev.xproperty.window, xa->a);
 355           if (a == None)
 356             continue;
 357           if (xa->m == 0)
 358             goto exit;
 359           for (xm = xa->m; xm; xm = xm->next) {
 360             if (a == xm->a)
 361               goto exit;
 362           }
 363         }
 364         break;
 365     }
 366   }
 367
 368   /* --- Finished: report the result if necessary --- */
 369
 370 exit:
 371   if (atoms->next) {
 372     fputs(XGetAtomName(dpy, xa->a), stdout);
 373     if (!xa->m || xa->m->next)
 374       printf(": %s\n", XGetAtomName(dpy, a));
 375     else
 376       fputc('\n', stdout);
 377   } else if (!xa->m || xa->m->next)
 378     printf("%s\n", XGetAtomName(dpy, a));
 379
 380   /* --- Go away --- */
 381
 382   tidy(0);
 383   return (0);
 384 }
 385
 386 /*----- That's all, folks -------------------------------------------------*/