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

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