3 * $Id: xwait.c,v 1.5 1998/11/30 22:36:53 mdw Exp $
5 * Wait until prodded by another X client
7 * (c) 1998 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the Edgeware X tools collection.
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.
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.
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.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.5 1998/11/30 22:36:53 mdw
33 * Tidy up tabbing in help texts very slightly.
35 * Revision 1.4 1998/11/21 22:41:19 mdw
36 * Reap children which die before I get my signal handler installed.
38 * Revision 1.3 1998/11/21 22:30:27 mdw
39 * Support GNU-style long options throughout, and introduce proper help
40 * text to all programs. Update manual pages to match.
42 * Revision 1.2 1998/11/18 21:25:06 mdw
43 * Reap dead children as they arrive. The previous shell may have
44 * carelessly left them behind.
46 * Revision 1.1 1998/11/16 23:00:49 mdw
51 /*----- Header files ------------------------------------------------------*/
58 #include <sys/types.h>
63 #include <X11/Xutil.h>
69 /*----- Main code ---------------------------------------------------------*/
71 /* --- @sigchld@ --- */
73 static void sigchld(int sig)
75 while (waitpid(-1, 0, WNOHANG) > 0)
81 static void version(FILE *fp)
83 fprintf(fp, "%s (xtoys version " VERSION ")\n", QUIS);
86 static void usage(FILE *fp)
88 fprintf(fp, "Usage: %s [-f] [-d DISPLAY] [-a ATOM] [-m MSG]\n", QUIS);
91 int main(int argc, char *argv[])
97 char *atom = XWAIT_DIE;
98 char *msg = XWAIT_DIE_MSG;
105 /* --- Parse options --- */
110 static struct option opt[] = {
111 { "help", 0, 0, 'h' },
112 { "usage", 0, 0, 'u' },
113 { "version", 0, 0, 'v' },
114 { "display", required_argument, 0, 'd' },
115 { "atom", required_argument, 0, 'a' },
116 { "msg", required_argument, 0, 'm' },
117 { "force", 0, 0, 'f' },
121 int i = getopt_long(argc, argv, "d:a:m:f", opt, 0);
131 "Waits until signalled by `xtell' or `xshutdown'. Specifically, waits\n"
132 "until a property with name ATOM is written to the root window with\n"
137 "-h, --help Display this help text\n"
138 "-u, --usage Display a short usage summary\n"
139 "-v, --version Display the program's version number\n"
141 "-d, --display=DISPLAY Choose X display to connect to\n"
142 "-f, --force Run even if this property is waited for by another\n"
144 "-a, --atom=ATOM\t Choose property name to listen for\n"
145 "-m, --msg=MSG Choose value of property to wait for\n",
177 /* --- Connect to the X display --- */
179 dpy = XOpenDisplay(display);
181 fprintf(stderr, "xwait: couldn't open display\n");
185 /* --- Fetch the property name atom --- */
187 xwait_die = XInternAtom(dpy, atom, False);
189 /* --- Mark ourselves as listening to all the screens --- */
193 int nsc = ScreenCount(dpy);
195 /* --- First pass: make sure there's not a process already here --- */
197 if ((f & f_force) == 0) {
198 for (i = 0; i < nsc; i++) {
199 Window win = RootWindow(dpy, i);
202 if (XGetTextProperty(dpy, win, &prop, xwait_die)) {
203 fprintf(stderr, "xwait: already waiting for `%s'\n", atom);
209 /* --- Second pass: set up listening to the property --- */
211 for (i = 0; i < nsc; i++) {
212 Window win = RootWindow(dpy, i);
214 char *imsg = "XWAIT_READY";
216 XStringListToTextProperty(&imsg, 1, &prop);
217 XSetTextProperty(dpy, win, &prop, xwait_die);
218 XSelectInput(dpy, win, PropertyChangeMask);
222 /* --- Set up a handler when children die --- *
224 * I don't fork any children? Why is this useful? Because I've been
225 * execed from a shell which started lots of background processes, and
226 * they'll zombie themselves otherwise.
233 /* --- Set the handler up --- */
235 sa.sa_handler = sigchld;
236 sigemptyset(&sa.sa_mask);
237 sigaddset(&sa.sa_mask, SIGCHLD);
239 sigaction(SIGCHLD, &sa, 0);
241 /* --- Now reap any which have been waiting around so far --- */
244 sigaddset(&ss, SIGCHLD);
245 sigprocmask(SIG_BLOCK, &ss, &oss);
247 sigprocmask(SIG_SETMASK, &oss, 0);
250 /* --- Now wait for an event --- */
253 XNextEvent(dpy, &ev);
256 if (ev.xproperty.atom == xwait_die) {
261 if (XGetTextProperty(dpy, ev.xproperty.window, &prop, xwait_die)) {
262 XTextPropertyToStringList(&prop, &sl, &c);
263 if (strcmp(sl[0], msg) == 0)
271 /* --- Finished: remove the property from all the screens --- */
276 int nsc = ScreenCount(dpy);
278 for (i = 0; i < nsc; i++)
279 XDeleteProperty(dpy, RootWindow(dpy, i), xwait_die);
282 /* --- Go away --- */
288 /*----- That's all, folks -------------------------------------------------*/