| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: xwait.c,v 1.7 1999/06/19 23:42:37 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 1.7 1999/06/19 23:42:37 mdw |
| 33 | * Improve signal handling. |
| 34 | * |
| 35 | * Revision 1.6 1998/12/11 09:50:07 mdw |
| 36 | * Minor modifications to work with mLib and mgLib. |
| 37 | * |
| 38 | * Revision 1.5 1998/11/30 22:36:53 mdw |
| 39 | * Tidy up tabbing in help texts very slightly. |
| 40 | * |
| 41 | * Revision 1.4 1998/11/21 22:41:19 mdw |
| 42 | * Reap children which die before I get my signal handler installed. |
| 43 | * |
| 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 | * |
| 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 | * |
| 52 | * Revision 1.1 1998/11/16 23:00:49 mdw |
| 53 | * Initial versions. |
| 54 | * |
| 55 | */ |
| 56 | |
| 57 | /*----- Header files ------------------------------------------------------*/ |
| 58 | |
| 59 | #include <errno.h> |
| 60 | #include <signal.h> |
| 61 | #include <stdio.h> |
| 62 | #include <stdlib.h> |
| 63 | #include <string.h> |
| 64 | |
| 65 | #include <sys/types.h> |
| 66 | #include <sys/wait.h> |
| 67 | #include <unistd.h> |
| 68 | |
| 69 | #include <X11/Xlib.h> |
| 70 | #include <X11/Xutil.h> |
| 71 | |
| 72 | #include <mLib/mdwopt.h> |
| 73 | #include <mLib/quis.h> |
| 74 | |
| 75 | #include "xwait.h" |
| 76 | |
| 77 | /*----- Main code ---------------------------------------------------------*/ |
| 78 | |
| 79 | /* --- @sigchld@ --- */ |
| 80 | |
| 81 | static void sigchld(int sig) |
| 82 | { |
| 83 | int e = errno; |
| 84 | while (waitpid(-1, 0, WNOHANG) > 0) |
| 85 | ; |
| 86 | errno = e; |
| 87 | } |
| 88 | |
| 89 | /* --- @main@ --- */ |
| 90 | |
| 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 | |
| 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 | |
| 117 | ego(argv[0]); |
| 118 | |
| 119 | for (;;) { |
| 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); |
| 132 | if (i < 0) |
| 133 | break; |
| 134 | switch (i) { |
| 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" |
| 154 | "-a, --atom=ATOM\t Choose property name to listen for\n" |
| 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 | |
| 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: |
| 181 | usage(stderr); |
| 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 | |
| 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; |
| 241 | sigset_t ss, oss; |
| 242 | |
| 243 | /* --- Set the handler up --- */ |
| 244 | |
| 245 | sa.sa_handler = sigchld; |
| 246 | sigemptyset(&sa.sa_mask); |
| 247 | sigaddset(&sa.sa_mask, SIGCHLD); |
| 248 | sa.sa_flags = SA_NOCLDSTOP; |
| 249 | #ifdef SA_RESTART |
| 250 | sa.sa_flags |= SA_RESTART; |
| 251 | #endif |
| 252 | sigaction(SIGCHLD, &sa, 0); |
| 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); |
| 261 | } |
| 262 | |
| 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 -------------------------------------------------*/ |