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

   1 /* -*-c-*-
   2  *
   3  * $Id: xcatch.c,v 1.9 2002/01/13 14:43:27 mdw Exp $
   4  *
   5  * Catch input and trap it in an X window
   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: xcatch.c,v $
  32  * Revision 1.9  2002/01/13 14:43:27  mdw
  33  * Kill some spurious warnings.  Track @msg@ interface change.
  34  *
  35  * Revision 1.8  1999/06/19 23:42:55  mdw
  36  * Improve signal handling.  Fix options parsing to POSIX order only.
  37  *
  38  * Revision 1.7  1999/05/21 22:09:19  mdw
  39  * Take advantage of new dynamic string macros.
  40  *
  41  * Revision 1.6  1999/05/19 20:41:15  mdw
  42  * Track gratuitous change in mdwopt interface.
  43  *
  44  * Revision 1.5  1999/05/05 18:55:18  mdw
  45  * Block SIGCHLD around the `fork' call to prevent a race.
  46  *
  47  * Revision 1.4  1999/03/24 22:23:57  mdw
  48  * Improve display for large files.  Keep newly added material in view if
  49  * scrolled to bottom of window.
  50  *
  51  * Revision 1.3  1998/12/20 17:19:16  mdw
  52  * Return exit status of child process, rather than always returning
  53  * success.
  54  *
  55  * Revision 1.2  1998/12/16 00:10:58  mdw
  56  * Fix tabbing in help text.
  57  *
  58  * Revision 1.1  1998/12/15 23:46:50  mdw
  59  * New program: captures input and puts it in a window.
  60  *
  61  */
  62
  63 /*----- Header files ------------------------------------------------------*/
  64
  65 #include <errno.h>
  66 #include <signal.h>
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70
  71 #include <sys/types.h>
  72 #include <sys/wait.h>
  73
  74 #include <fcntl.h>
  75 #include <unistd.h>
  76
  77 #include <gtk/gtk.h>
  78
  79 #include <mLib/dstr.h>
  80 #include <mLib/mdwopt.h>
  81 #include <mLib/report.h>
  82 #include <mLib/quis.h>
  83
  84 #include <mgLib/cancel.h>
  85 #include <mgLib/msg.h>
  86
  87 /*----- Inportant state ---------------------------------------------------*/
  88
  89 static unsigned int flags;
  90
  91 #define f_closed 1u
  92 #define f_bogus 2u
  93
  94 static GtkWidget *textbox = 0;
  95 static GdkFont *font;
  96
  97 static pid_t kid = -1;
  98 static int status;
  99
 100 /*----- Main code ---------------------------------------------------------*/
 101
 102 /* --- The window's closed --- */
 103
 104 static void killwin(GtkWidget *w, gpointer p)
 105 {
 106   if (flags & f_closed)
 107     gtk_main_quit();
 108   else
 109     textbox = 0;
 110 }
 111
 112 /* --- Some input has arrived --- */
 113
 114 static void ready(gpointer data, gint fd, GdkInputCondition c)
 115 {
 116   char buf[1024];
 117   int doscroll = 1;
 118   GtkText *t = 0;
 119   GtkAdjustment *va = 0;
 120
 121   /* --- If not ready to read then go away --- */
 122
 123   if (!(c & GDK_INPUT_READ))
 124     return;
 125
 126   /* --- Decide whether to scroll the window --- */
 127
 128   if (textbox) {
 129     t = GTK_TEXT(textbox);
 130     va = t->vadj;
 131     if (va->value + va->page_size < va->upper)
 132       doscroll = 0;
 133     gtk_text_freeze(t);
 134   }
 135
 136   /* --- Read data into the buffer --- *
 137    *
 138    * This is a bit of a mess.
 139    */
 140
 141   for (;;) {
 142     int r = read(fd, buf, sizeof(buf));
 143
 144     /* --- The read failed --- *
 145      *
 146      * Maybe there's no more data to read.  In this case, we get
 147      * @EWOULDBLOCK@, indicating it's time to stop and do something else.
 148      * Otherwise something serious has happened.
 149      */
 150
 151     if (r < 0) {
 152       if (errno == EWOULDBLOCK)
 153         break;
 154       msg(QUIS, ":~OK", "error reading data: %s", strerror(errno));
 155       exit(EXIT_FAILURE);
 156     }
 157
 158     /* --- End of file --- *
 159      *
 160      * If the box is closed, then exit quiety; otherwise wait for it to
 161      * go away.
 162      */
 163
 164     if (r == 0) {
 165       close(fd);
 166       if (textbox)
 167         flags |= f_closed;
 168       else
 169         gtk_main_quit();
 170       break;
 171     }
 172
 173     /* --- If there's no output window, create one --- */
 174
 175     if (!textbox) {
 176       GtkWidget *win;
 177       GtkWidget *tbl;
 178       GtkWidget *w;
 179
 180       win = gtk_dialog_new();
 181       gtk_window_set_policy(GTK_WINDOW(win), 1, 1, 0);
 182       gtk_signal_connect(GTK_OBJECT(win), "destroy",
 183                          GTK_SIGNAL_FUNC(killwin), 0);
 184
 185       tbl = gtk_table_new(2, 2, 0);
 186       gtk_container_border_width(GTK_CONTAINER(tbl), 8);
 187       gtk_box_pack_start(GTK_BOX(GTK_DIALOG(win)->vbox), tbl, 1, 1, 1);
 188       gtk_widget_show(tbl);
 189
 190       textbox = gtk_text_new(0, 0);
 191       t = GTK_TEXT(textbox);
 192       va = t->vadj;
 193       gtk_table_attach(GTK_TABLE(tbl), textbox, 0, 1, 0, 1,
 194                        GTK_EXPAND | GTK_SHRINK | GTK_FILL,
 195                        GTK_EXPAND | GTK_SHRINK | GTK_FILL,
 196                        0, 0);
 197       gtk_text_set_editable(t, 0);
 198       gtk_widget_set_usize(textbox, 500, 300);
 199       gtk_text_freeze(t);
 200       gtk_widget_show(textbox);
 201
 202       w = gtk_vscrollbar_new(va);
 203       gtk_table_attach(GTK_TABLE(tbl), w, 1, 2, 0, 1,
 204                        0, GTK_EXPAND | GTK_SHRINK | GTK_FILL, 0, 0);
 205       gtk_widget_show(w);
 206
 207       w = gtk_hscrollbar_new(t->hadj);
 208       gtk_table_attach(GTK_TABLE(tbl), w, 0, 1, 1, 2,
 209                        GTK_EXPAND | GTK_SHRINK | GTK_FILL, 0, 0, 0);
 210       gtk_widget_show(w);
 211
 212       gtk_box_set_homogeneous(GTK_BOX(GTK_DIALOG(win)->action_area), 0);
 213       w = gtk_button_new_with_label("Dismiss");
 214       gtk_signal_connect_object(GTK_OBJECT(w), "clicked",
 215                                 GTK_SIGNAL_FUNC(gtk_object_destroy),
 216                                 GTK_OBJECT(win));
 217       gtk_box_pack_end(GTK_BOX(GTK_DIALOG(win)->action_area), w, 0, 0, 0);
 218       GTK_WIDGET_SET_FLAGS(w, GTK_CAN_DEFAULT);
 219       gtk_widget_grab_default(w);
 220       cancel(GTK_WINDOW(win), w);
 221       gtk_widget_show(w);
 222
 223       gtk_widget_show(win);
 224     }
 225
 226     gtk_text_insert(t, font, 0, 0, buf, r);
 227   }
 228
 229   if (textbox) {
 230     gtk_text_thaw(t);
 231     if (doscroll)
 232       gtk_adjustment_set_value(va, va->upper - va->page_size);
 233   }
 234 }
 235
 236 /* --- Signal handler --- */
 237
 238 static void reap(int sig)
 239 {
 240   pid_t k;
 241   int s;
 242   int e = errno;
 243
 244   for (;;) {
 245     k = waitpid(-1, &s, WNOHANG);
 246     if (k <= 0)
 247       break;
 248     if (k == kid) {
 249       if (WIFEXITED(s))
 250         status = WEXITSTATUS(s);
 251       else
 252         status = 127;
 253     }
 254   }
 255   errno = e;
 256 }
 257
 258 /* --- Main program --- */
 259
 260 static void version(FILE *fp)
 261 {
 262   fprintf(fp, "%s (xtoys version " VERSION ")\n", QUIS);
 263 }
 264
 265 static void usage(FILE *fp)
 266 {
 267   fprintf(fp, "Usage: %s [-f file] [-F font] [command [args...]]\n", QUIS);
 268 }
 269
 270 int main(int argc, char *argv[])
 271 {
 272   int fd = -1;
 273
 274   ego(argv[0]);
 275
 276   gtk_init(&argc, &argv);
 277
 278   for (;;) {
 279     static struct option opt[] = {
 280       { "help",         0,              0,      'h' },
 281       { "usage",        0,              0,      'u' },
 282       { "version",      0,              0,      'v' },
 283       { "file",         OPTF_ARGREQ,    0,      'f' },
 284       { "font",         OPTF_ARGREQ,    0,      'F' },
 285       { 0,              0,              0,      0 }
 286     };
 287     int i = mdwopt(argc, argv, "+huvf:F:", opt, 0, 0, 0);
 288
 289     if (i < 0)
 290       break;
 291
 292     switch (i) {
 293       case 'h':
 294         version(stdout);
 295         fputc('\n', stdout);
 296         usage(stdout);
 297         fputs(
 298 "\n"
 299 "Catches input from a pipe or other source, and captures it in a window.\n"
 300 "Nothing is displayed if there's no input.\n"
 301 "\n"
 302 "Options provided:\n"
 303 "\n"
 304 "-h, --help             Display this help text\n"
 305 "-u, --usage            Display a quick usage summary\n"
 306 "-v, --version          Display the version number\n"
 307 "-f, --file=FILE\t      Read input from the named file\n"
 308 "-F, --font=FONT\t      Display output in the named font\n",
 309           stdout);
 310         exit(0);
 311         break;
 312       case 'u':
 313         usage(stdout);
 314         exit(0);
 315         break;
 316       case 'v':
 317         version(stdout);
 318         exit(0);
 319         break;
 320       case 'f':
 321         if ((fd = open(optarg, O_RDONLY)) < 0) {
 322           die(1, "couldn't open file: %s", strerror(errno));
 323           exit(1);
 324         }
 325         break;
 326       case 'F':
 327         font = gdk_font_load(optarg);
 328         break;
 329       default:
 330         flags |= f_bogus;
 331         break;
 332     }
 333   }
 334
 335   if (flags & f_bogus) {
 336     usage(stderr);
 337     exit(1);
 338   }
 339
 340   if (fd == -1) {
 341     if (optind == argc)
 342       fd = STDIN_FILENO;
 343     else {
 344       int pfd[2];
 345       struct sigaction sa;
 346       sigset_t newmask, oldmask;
 347
 348       /* --- Set up a signal handler --- */
 349
 350       sa.sa_handler = reap;
 351       sigemptyset(&sa.sa_mask);
 352       sa.sa_flags = SA_NOCLDSTOP;
 353 #ifdef SA_RESTART
 354       sa.sa_flags |= SA_RESTART;
 355 #endif
 356       sigaction(SIGCHLD, &sa, 0);
 357
 358       /* --- Start a child program --- */
 359
 360       if (pipe(pfd))
 361         die(1, "couldn't open pipe: %s", strerror(errno));
 362
 363       sigemptyset(&newmask);
 364       sigaddset(&newmask, SIGCHLD);
 365       sigprocmask(SIG_BLOCK, &newmask, &oldmask);
 366
 367       kid = fork();
 368       if (kid < 0)
 369         die(1, "couldn't fork: %s", strerror(errno));
 370       if (kid == 0) {
 371         dstr d = DSTR_INIT;
 372
 373         close(pfd[0]);
 374         if (pfd[1] != STDOUT_FILENO)
 375           dup2(pfd[1], STDOUT_FILENO);
 376         if (pfd[1] != STDERR_FILENO)
 377           dup2(pfd[1], STDERR_FILENO);
 378         if (pfd[1] != STDOUT_FILENO && pfd[1] != STDERR_FILENO)
 379           close(pfd[1]);
 380         execvp(argv[optind], argv + optind);
 381
 382         dstr_putf(&d, "%s: couldn't run `%s': %s\n",
 383                   QUIS, argv[optind], strerror(errno));
 384         write(STDERR_FILENO, d.buf, d.len);
 385         dstr_destroy(&d);
 386         _exit(127);
 387       }
 388
 389       sigprocmask(SIG_SETMASK, &oldmask, 0);
 390       fd = pfd[0];
 391       close(pfd[1]);
 392     }
 393   }
 394
 395   {
 396     int f = fcntl(fd, F_GETFL);
 397     fcntl(fd, F_SETFL, f | O_NONBLOCK);
 398   }
 399
 400   gdk_input_add(fd, GDK_INPUT_READ, ready, 0);
 401   gtk_main();
 402   return (status);
 403 }
 404
 405 /*----- That's all, folks -------------------------------------------------*/