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

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