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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: xwait.c,v 1.2 1998/11/18 21:25:06 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 1.2 1998/11/18 21:25:06 mdw |
33 | * Reap dead children as they arrive. The previous shell may have |
34 | * carelessly left them behind. |
35 | * |
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36 | * Revision 1.1 1998/11/16 23:00:49 mdw |
37 | * Initial versions. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
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43 | #include <signal.h> |
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44 | #include <stdio.h> |
45 | #include <stdlib.h> |
46 | #include <string.h> |
47 | |
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48 | #include <sys/types.h> |
49 | #include <sys/wait.h> |
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50 | #include <unistd.h> |
51 | |
52 | #include <X11/Xlib.h> |
53 | #include <X11/Xutil.h> |
54 | |
55 | #include "xwait.h" |
56 | |
57 | /*----- Main code ---------------------------------------------------------*/ |
58 | |
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59 | /* --- @sigchld@ --- */ |
60 | |
61 | static void sigchld(int sig) |
62 | { |
63 | while (waitpid(-1, 0, WNOHANG) > 0) |
64 | ; |
65 | } |
66 | |
67 | /* --- @main@ --- */ |
68 | |
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69 | int main(int argc, char *argv[]) |
70 | { |
71 | char *display = 0; |
72 | Display *dpy; |
73 | Atom xwait_die; |
74 | XEvent ev; |
75 | char *atom = XWAIT_DIE; |
76 | char *msg = XWAIT_DIE_MSG; |
77 | unsigned f = 0; |
78 | |
79 | enum { |
80 | f_force = 1 |
81 | }; |
82 | |
83 | /* --- Parse options --- */ |
84 | |
85 | for (;;) { |
86 | int i = getopt(argc, argv, "d:a:m:f"); |
87 | if (i < 0) |
88 | break; |
89 | switch (i) { |
90 | case 'd': |
91 | display = optarg; |
92 | break; |
93 | case 'a': |
94 | atom = optarg; |
95 | break; |
96 | case 'm': |
97 | msg = optarg; |
98 | break; |
99 | case 'f': |
100 | f |= f_force; |
101 | break; |
102 | default: |
103 | fprintf(stderr, |
104 | "Usage: xwait [-f] [-d DISPLAY] [-a ATOM] [-m MSG]\n"); |
105 | exit(EXIT_FAILURE); |
106 | break; |
107 | } |
108 | } |
109 | |
110 | /* --- Connect to the X display --- */ |
111 | |
112 | dpy = XOpenDisplay(display); |
113 | if (!dpy) { |
114 | fprintf(stderr, "xwait: couldn't open display\n"); |
115 | exit(EXIT_FAILURE); |
116 | } |
117 | |
118 | /* --- Fetch the property name atom --- */ |
119 | |
120 | xwait_die = XInternAtom(dpy, atom, False); |
121 | |
122 | /* --- Mark ourselves as listening to all the screens --- */ |
123 | |
124 | { |
125 | int i; |
126 | int nsc = ScreenCount(dpy); |
127 | |
128 | /* --- First pass: make sure there's not a process already here --- */ |
129 | |
130 | if ((f & f_force) == 0) { |
131 | for (i = 0; i < nsc; i++) { |
132 | Window win = RootWindow(dpy, i); |
133 | XTextProperty prop; |
134 | |
135 | if (XGetTextProperty(dpy, win, &prop, xwait_die)) { |
136 | fprintf(stderr, "xwait: already waiting for `%s'\n", atom); |
137 | exit(EXIT_FAILURE); |
138 | } |
139 | } |
140 | } |
141 | |
142 | /* --- Second pass: set up listening to the property --- */ |
143 | |
144 | for (i = 0; i < nsc; i++) { |
145 | Window win = RootWindow(dpy, i); |
146 | XTextProperty prop; |
147 | char *imsg = "XWAIT_READY"; |
148 | |
149 | XStringListToTextProperty(&imsg, 1, &prop); |
150 | XSetTextProperty(dpy, win, &prop, xwait_die); |
151 | XSelectInput(dpy, win, PropertyChangeMask); |
152 | } |
153 | } |
154 | |
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155 | /* --- Set up a handler when children die --- * |
156 | * |
157 | * I don't fork any children? Why is this useful? Because I've been |
158 | * execed from a shell which started lots of background processes, and |
159 | * they'll zombie themselves otherwise. |
160 | */ |
161 | |
162 | { |
163 | struct sigaction sa; |
164 | |
165 | sa.sa_handler = sigchld; |
166 | sigemptyset(&sa.sa_mask); |
167 | sigaddset(&sa.sa_mask, SIGCHLD); |
168 | sa.sa_flags = 0; |
169 | sigaction(SIGCHLD, &sa, 0); |
170 | } |
171 | |
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172 | /* --- Now wait for an event --- */ |
173 | |
174 | for (;;) { |
175 | XNextEvent(dpy, &ev); |
176 | switch (ev.type) { |
177 | case PropertyNotify: |
178 | if (ev.xproperty.atom == xwait_die) { |
179 | XTextProperty prop; |
180 | char **sl; |
181 | int c; |
182 | |
183 | if (XGetTextProperty(dpy, ev.xproperty.window, &prop, xwait_die)) { |
184 | XTextPropertyToStringList(&prop, &sl, &c); |
185 | if (strcmp(sl[0], msg) == 0) |
186 | goto exit; |
187 | XFreeStringList(sl); |
188 | } |
189 | } |
190 | } |
191 | } |
192 | |
193 | /* --- Finished: remove the property from all the screens --- */ |
194 | |
195 | exit: |
196 | { |
197 | int i; |
198 | int nsc = ScreenCount(dpy); |
199 | |
200 | for (i = 0; i < nsc; i++) |
201 | XDeleteProperty(dpy, RootWindow(dpy, i), xwait_die); |
202 | } |
203 | |
204 | /* --- Go away --- */ |
205 | |
206 | XCloseDisplay(dpy); |
207 | return (0); |
208 | } |
209 | |
210 | /*----- That's all, folks -------------------------------------------------*/ |