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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: xwait.c,v 1.7 1999/06/19 23:42:37 mdw Exp $ |
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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 $ |
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32 | * Revision 1.7 1999/06/19 23:42:37 mdw |
33 | * Improve signal handling. |
34 | * |
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35 | * Revision 1.6 1998/12/11 09:50:07 mdw |
36 | * Minor modifications to work with mLib and mgLib. |
37 | * |
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38 | * Revision 1.5 1998/11/30 22:36:53 mdw |
39 | * Tidy up tabbing in help texts very slightly. |
40 | * |
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41 | * Revision 1.4 1998/11/21 22:41:19 mdw |
42 | * Reap children which die before I get my signal handler installed. |
43 | * |
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44 | * Revision 1.3 1998/11/21 22:30:27 mdw |
45 | * Support GNU-style long options throughout, and introduce proper help |
46 | * text to all programs. Update manual pages to match. |
47 | * |
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48 | * Revision 1.2 1998/11/18 21:25:06 mdw |
49 | * Reap dead children as they arrive. The previous shell may have |
50 | * carelessly left them behind. |
51 | * |
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52 | * Revision 1.1 1998/11/16 23:00:49 mdw |
53 | * Initial versions. |
54 | * |
55 | */ |
56 | |
57 | /*----- Header files ------------------------------------------------------*/ |
58 | |
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59 | #include <errno.h> |
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60 | #include <signal.h> |
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61 | #include <stdio.h> |
62 | #include <stdlib.h> |
63 | #include <string.h> |
64 | |
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65 | #include <sys/types.h> |
66 | #include <sys/wait.h> |
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67 | #include <unistd.h> |
68 | |
69 | #include <X11/Xlib.h> |
70 | #include <X11/Xutil.h> |
71 | |
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72 | #include <mLib/mdwopt.h> |
73 | #include <mLib/quis.h> |
74 | |
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75 | #include "xwait.h" |
76 | |
77 | /*----- Main code ---------------------------------------------------------*/ |
78 | |
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79 | /* --- @sigchld@ --- */ |
80 | |
81 | static void sigchld(int sig) |
82 | { |
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83 | int e = errno; |
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84 | while (waitpid(-1, 0, WNOHANG) > 0) |
85 | ; |
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86 | errno = e; |
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87 | } |
88 | |
89 | /* --- @main@ --- */ |
90 | |
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91 | static void version(FILE *fp) |
92 | { |
93 | fprintf(fp, "%s (xtoys version " VERSION ")\n", QUIS); |
94 | } |
95 | |
96 | static void usage(FILE *fp) |
97 | { |
98 | fprintf(fp, "Usage: %s [-f] [-d DISPLAY] [-a ATOM] [-m MSG]\n", QUIS); |
99 | } |
100 | |
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101 | int main(int argc, char *argv[]) |
102 | { |
103 | char *display = 0; |
104 | Display *dpy; |
105 | Atom xwait_die; |
106 | XEvent ev; |
107 | char *atom = XWAIT_DIE; |
108 | char *msg = XWAIT_DIE_MSG; |
109 | unsigned f = 0; |
110 | |
111 | enum { |
112 | f_force = 1 |
113 | }; |
114 | |
115 | /* --- Parse options --- */ |
116 | |
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117 | ego(argv[0]); |
118 | |
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119 | for (;;) { |
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120 | static struct option opt[] = { |
121 | { "help", 0, 0, 'h' }, |
122 | { "usage", 0, 0, 'u' }, |
123 | { "version", 0, 0, 'v' }, |
124 | { "display", required_argument, 0, 'd' }, |
125 | { "atom", required_argument, 0, 'a' }, |
126 | { "msg", required_argument, 0, 'm' }, |
127 | { "force", 0, 0, 'f' }, |
128 | { 0, 0, 0, 0 } |
129 | }; |
130 | |
131 | int i = getopt_long(argc, argv, "d:a:m:f", opt, 0); |
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132 | if (i < 0) |
133 | break; |
134 | switch (i) { |
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135 | case 'h': |
136 | version(stdout); |
137 | fputs("\n", stdout); |
138 | usage(stdout); |
139 | fputs( |
140 | "\n" |
141 | "Waits until signalled by `xtell' or `xshutdown'. Specifically, waits\n" |
142 | "until a property with name ATOM is written to the root window with\n" |
143 | "contents MSG.\n" |
144 | "\n" |
145 | "Options:\n" |
146 | "\n" |
147 | "-h, --help Display this help text\n" |
148 | "-u, --usage Display a short usage summary\n" |
149 | "-v, --version Display the program's version number\n" |
150 | "\n" |
151 | "-d, --display=DISPLAY Choose X display to connect to\n" |
152 | "-f, --force Run even if this property is waited for by another\n" |
153 | " process\n" |
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154 | "-a, --atom=ATOM\t Choose property name to listen for\n" |
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155 | "-m, --msg=MSG Choose value of property to wait for\n", |
156 | stdout); |
157 | exit(0); |
158 | break; |
159 | case 'u': |
160 | usage(stdout); |
161 | exit(0); |
162 | break; |
163 | case 'v': |
164 | version(stdout); |
165 | exit(0); |
166 | break; |
167 | |
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168 | case 'd': |
169 | display = optarg; |
170 | break; |
171 | case 'a': |
172 | atom = optarg; |
173 | break; |
174 | case 'm': |
175 | msg = optarg; |
176 | break; |
177 | case 'f': |
178 | f |= f_force; |
179 | break; |
180 | default: |
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181 | usage(stderr); |
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182 | exit(EXIT_FAILURE); |
183 | break; |
184 | } |
185 | } |
186 | |
187 | /* --- Connect to the X display --- */ |
188 | |
189 | dpy = XOpenDisplay(display); |
190 | if (!dpy) { |
191 | fprintf(stderr, "xwait: couldn't open display\n"); |
192 | exit(EXIT_FAILURE); |
193 | } |
194 | |
195 | /* --- Fetch the property name atom --- */ |
196 | |
197 | xwait_die = XInternAtom(dpy, atom, False); |
198 | |
199 | /* --- Mark ourselves as listening to all the screens --- */ |
200 | |
201 | { |
202 | int i; |
203 | int nsc = ScreenCount(dpy); |
204 | |
205 | /* --- First pass: make sure there's not a process already here --- */ |
206 | |
207 | if ((f & f_force) == 0) { |
208 | for (i = 0; i < nsc; i++) { |
209 | Window win = RootWindow(dpy, i); |
210 | XTextProperty prop; |
211 | |
212 | if (XGetTextProperty(dpy, win, &prop, xwait_die)) { |
213 | fprintf(stderr, "xwait: already waiting for `%s'\n", atom); |
214 | exit(EXIT_FAILURE); |
215 | } |
216 | } |
217 | } |
218 | |
219 | /* --- Second pass: set up listening to the property --- */ |
220 | |
221 | for (i = 0; i < nsc; i++) { |
222 | Window win = RootWindow(dpy, i); |
223 | XTextProperty prop; |
224 | char *imsg = "XWAIT_READY"; |
225 | |
226 | XStringListToTextProperty(&imsg, 1, &prop); |
227 | XSetTextProperty(dpy, win, &prop, xwait_die); |
228 | XSelectInput(dpy, win, PropertyChangeMask); |
229 | } |
230 | } |
231 | |
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232 | /* --- Set up a handler when children die --- * |
233 | * |
234 | * I don't fork any children? Why is this useful? Because I've been |
235 | * execed from a shell which started lots of background processes, and |
236 | * they'll zombie themselves otherwise. |
237 | */ |
238 | |
239 | { |
240 | struct sigaction sa; |
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241 | sigset_t ss, oss; |
242 | |
243 | /* --- Set the handler up --- */ |
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244 | |
245 | sa.sa_handler = sigchld; |
246 | sigemptyset(&sa.sa_mask); |
247 | sigaddset(&sa.sa_mask, SIGCHLD); |
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248 | sa.sa_flags = SA_NOCLDSTOP; |
249 | #ifdef SA_RESTART |
250 | sa.sa_flags |= SA_RESTART; |
251 | #endif |
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252 | sigaction(SIGCHLD, &sa, 0); |
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253 | |
254 | /* --- Now reap any which have been waiting around so far --- */ |
255 | |
256 | sigemptyset(&ss); |
257 | sigaddset(&ss, SIGCHLD); |
258 | sigprocmask(SIG_BLOCK, &ss, &oss); |
259 | sigchld(SIGCHLD); |
260 | sigprocmask(SIG_SETMASK, &oss, 0); |
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261 | } |
262 | |
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263 | /* --- Now wait for an event --- */ |
264 | |
265 | for (;;) { |
266 | XNextEvent(dpy, &ev); |
267 | switch (ev.type) { |
268 | case PropertyNotify: |
269 | if (ev.xproperty.atom == xwait_die) { |
270 | XTextProperty prop; |
271 | char **sl; |
272 | int c; |
273 | |
274 | if (XGetTextProperty(dpy, ev.xproperty.window, &prop, xwait_die)) { |
275 | XTextPropertyToStringList(&prop, &sl, &c); |
276 | if (strcmp(sl[0], msg) == 0) |
277 | goto exit; |
278 | XFreeStringList(sl); |
279 | } |
280 | } |
281 | } |
282 | } |
283 | |
284 | /* --- Finished: remove the property from all the screens --- */ |
285 | |
286 | exit: |
287 | { |
288 | int i; |
289 | int nsc = ScreenCount(dpy); |
290 | |
291 | for (i = 0; i < nsc; i++) |
292 | XDeleteProperty(dpy, RootWindow(dpy, i), xwait_die); |
293 | } |
294 | |
295 | /* --- Go away --- */ |
296 | |
297 | XCloseDisplay(dpy); |
298 | return (0); |
299 | } |
300 | |
301 | /*----- That's all, folks -------------------------------------------------*/ |