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

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