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

   1 /* -*-c-*-
   2  *
   3  * $Id: xcatch.c,v 1.10 2004/04/08 01:36:29 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 /*----- Header files ------------------------------------------------------*/
  30
  31 #include <errno.h>
  32 #include <signal.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36
  37 #include <sys/types.h>
  38 #include <sys/wait.h>
  39
  40 #include <fcntl.h>
  41 #include <unistd.h>
  42
  43 #include <gtk/gtk.h>
  44
  45 #include <mLib/dstr.h>
  46 #include <mLib/mdwopt.h>
  47 #include <mLib/report.h>
  48 #include <mLib/quis.h>
  49
  50 #include <mgLib/cancel.h>
  51 #include <mgLib/msg.h>
  52
  53 /*----- Inportant state ---------------------------------------------------*/
  54
  55 static unsigned int flags;
  56
  57 #define f_closed 1u
  58 #define f_bogus 2u
  59
  60 static GtkWidget *textbox = 0;
  61 static GdkFont *font;
  62
  63 static pid_t kid = -1;
  64 static int status;
  65
  66 /*----- Main code ---------------------------------------------------------*/
  67
  68 /* --- The window's closed --- */
  69
  70 static void killwin(GtkWidget *w, gpointer p)
  71 {
  72   if (flags & f_closed)
  73     gtk_main_quit();
  74   else
  75     textbox = 0;
  76 }
  77
  78 /* --- Some input has arrived --- */
  79
  80 static void ready(gpointer data, gint fd, GdkInputCondition c)
  81 {
  82   char buf[1024];
  83   int doscroll = 1;
  84   GtkText *t = 0;
  85   GtkAdjustment *va = 0;
  86
  87   /* --- If not ready to read then go away --- */
  88
  89   if (!(c & GDK_INPUT_READ))
  90     return;
  91
  92   /* --- Decide whether to scroll the window --- */
  93
  94   if (textbox) {
  95     t = GTK_TEXT(textbox);
  96     va = t->vadj;
  97     if (va->value + va->page_size < va->upper)
  98       doscroll = 0;
  99     gtk_text_freeze(t);
 100   }
 101
 102   /* --- Read data into the buffer --- *
 103    *
 104    * This is a bit of a mess.
 105    */
 106
 107   for (;;) {
 108     int r = read(fd, buf, sizeof(buf));
 109
 110     /* --- The read failed --- *
 111      *
 112      * Maybe there's no more data to read.  In this case, we get
 113      * @EWOULDBLOCK@, indicating it's time to stop and do something else.
 114      * Otherwise something serious has happened.
 115      */
 116
 117     if (r < 0) {
 118       if (errno == EWOULDBLOCK)
 119         break;
 120       msg(QUIS, ":~OK", "error reading data: %s", strerror(errno));
 121       exit(EXIT_FAILURE);
 122     }
 123
 124     /* --- End of file --- *
 125      *
 126      * If the box is closed, then exit quiety; otherwise wait for it to
 127      * go away.
 128      */
 129
 130     if (r == 0) {
 131       close(fd);
 132       if (textbox)
 133         flags |= f_closed;
 134       else
 135         gtk_main_quit();
 136       break;
 137     }
 138
 139     /* --- If there's no output window, create one --- */
 140
 141     if (!textbox) {
 142       GtkWidget *win;
 143       GtkWidget *tbl;
 144       GtkWidget *w;
 145
 146       win = gtk_dialog_new();
 147       gtk_window_set_policy(GTK_WINDOW(win), 1, 1, 0);
 148       gtk_signal_connect(GTK_OBJECT(win), "destroy",
 149                          GTK_SIGNAL_FUNC(killwin), 0);
 150
 151       tbl = gtk_table_new(2, 2, 0);
 152       gtk_container_border_width(GTK_CONTAINER(tbl), 8);
 153       gtk_box_pack_start(GTK_BOX(GTK_DIALOG(win)->vbox), tbl, 1, 1, 1);
 154       gtk_widget_show(tbl);
 155
 156       textbox = gtk_text_new(0, 0);
 157       t = GTK_TEXT(textbox);
 158       va = t->vadj;
 159       gtk_table_attach(GTK_TABLE(tbl), textbox, 0, 1, 0, 1,
 160                        GTK_EXPAND | GTK_SHRINK | GTK_FILL,
 161                        GTK_EXPAND | GTK_SHRINK | GTK_FILL,
 162                        0, 0);
 163       gtk_text_set_editable(t, 0);
 164       gtk_widget_set_usize(textbox, 500, 300);
 165       gtk_text_freeze(t);
 166       gtk_widget_show(textbox);
 167
 168       w = gtk_vscrollbar_new(va);
 169       gtk_table_attach(GTK_TABLE(tbl), w, 1, 2, 0, 1,
 170                        0, GTK_EXPAND | GTK_SHRINK | GTK_FILL, 0, 0);
 171       gtk_widget_show(w);
 172
 173       w = gtk_hscrollbar_new(t->hadj);
 174       gtk_table_attach(GTK_TABLE(tbl), w, 0, 1, 1, 2,
 175                        GTK_EXPAND | GTK_SHRINK | GTK_FILL, 0, 0, 0);
 176       gtk_widget_show(w);
 177
 178       gtk_box_set_homogeneous(GTK_BOX(GTK_DIALOG(win)->action_area), 0);
 179       w = gtk_button_new_with_label("Dismiss");
 180       gtk_signal_connect_object(GTK_OBJECT(w), "clicked",
 181                                 GTK_SIGNAL_FUNC(gtk_object_destroy),
 182                                 GTK_OBJECT(win));
 183       gtk_box_pack_end(GTK_BOX(GTK_DIALOG(win)->action_area), w, 0, 0, 0);
 184       GTK_WIDGET_SET_FLAGS(w, GTK_CAN_DEFAULT);
 185       gtk_widget_grab_default(w);
 186       cancel(GTK_WINDOW(win), w);
 187       gtk_widget_show(w);
 188
 189       gtk_widget_show(win);
 190     }
 191
 192     gtk_text_insert(t, font, 0, 0, buf, r);
 193   }
 194
 195   if (textbox) {
 196     gtk_text_thaw(t);
 197     if (doscroll)
 198       gtk_adjustment_set_value(va, va->upper - va->page_size);
 199   }
 200 }
 201
 202 /* --- Signal handler --- */
 203
 204 static void reap(int sig)
 205 {
 206   pid_t k;
 207   int s;
 208   int e = errno;
 209
 210   for (;;) {
 211     k = waitpid(-1, &s, WNOHANG);
 212     if (k <= 0)
 213       break;
 214     if (k == kid) {
 215       if (WIFEXITED(s))
 216         status = WEXITSTATUS(s);
 217       else
 218         status = 127;
 219     }
 220   }
 221   errno = e;
 222 }
 223
 224 /* --- Main program --- */
 225
 226 static void version(FILE *fp)
 227 {
 228   fprintf(fp, "%s (xtoys version " VERSION ")\n", QUIS);
 229 }
 230
 231 static void usage(FILE *fp)
 232 {
 233   fprintf(fp, "Usage: %s [-f file] [-F font] [command [args...]]\n", QUIS);
 234 }
 235
 236 int main(int argc, char *argv[])
 237 {
 238   int fd = -1;
 239
 240   ego(argv[0]);
 241
 242   gtk_init(&argc, &argv);
 243
 244   for (;;) {
 245     static struct option opt[] = {
 246       { "help",         0,              0,      'h' },
 247       { "usage",        0,              0,      'u' },
 248       { "version",      0,              0,      'v' },
 249       { "file",         OPTF_ARGREQ,    0,      'f' },
 250       { "font",         OPTF_ARGREQ,    0,      'F' },
 251       { 0,              0,              0,      0 }
 252     };
 253     int i = mdwopt(argc, argv, "+huvf:F:", opt, 0, 0, 0);
 254
 255     if (i < 0)
 256       break;
 257
 258     switch (i) {
 259       case 'h':
 260         version(stdout);
 261         fputc('\n', stdout);
 262         usage(stdout);
 263         fputs(
 264 "\n"
 265 "Catches input from a pipe or other source, and captures it in a window.\n"
 266 "Nothing is displayed if there's no input.\n"
 267 "\n"
 268 "Options provided:\n"
 269 "\n"
 270 "-h, --help             Display this help text\n"
 271 "-u, --usage            Display a quick usage summary\n"
 272 "-v, --version          Display the version number\n"
 273 "-f, --file=FILE\t      Read input from the named file\n"
 274 "-F, --font=FONT\t      Display output in the named font\n",
 275           stdout);
 276         exit(0);
 277         break;
 278       case 'u':
 279         usage(stdout);
 280         exit(0);
 281         break;
 282       case 'v':
 283         version(stdout);
 284         exit(0);
 285         break;
 286       case 'f':
 287         if ((fd = open(optarg, O_RDONLY)) < 0) {
 288           die(1, "couldn't open file: %s", strerror(errno));
 289           exit(1);
 290         }
 291         break;
 292       case 'F':
 293         font = gdk_font_load(optarg);
 294         break;
 295       default:
 296         flags |= f_bogus;
 297         break;
 298     }
 299   }
 300
 301   if (flags & f_bogus) {
 302     usage(stderr);
 303     exit(1);
 304   }
 305
 306   if (fd == -1) {
 307     if (optind == argc)
 308       fd = STDIN_FILENO;
 309     else {
 310       int pfd[2];
 311       struct sigaction sa;
 312       sigset_t newmask, oldmask;
 313
 314       /* --- Set up a signal handler --- */
 315
 316       sa.sa_handler = reap;
 317       sigemptyset(&sa.sa_mask);
 318       sa.sa_flags = SA_NOCLDSTOP;
 319 #ifdef SA_RESTART
 320       sa.sa_flags |= SA_RESTART;
 321 #endif
 322       sigaction(SIGCHLD, &sa, 0);
 323
 324       /* --- Start a child program --- */
 325
 326       if (pipe(pfd))
 327         die(1, "couldn't open pipe: %s", strerror(errno));
 328
 329       sigemptyset(&newmask);
 330       sigaddset(&newmask, SIGCHLD);
 331       sigprocmask(SIG_BLOCK, &newmask, &oldmask);
 332
 333       kid = fork();
 334       if (kid < 0)
 335         die(1, "couldn't fork: %s", strerror(errno));
 336       if (kid == 0) {
 337         dstr d = DSTR_INIT;
 338
 339         close(pfd[0]);
 340         if (pfd[1] != STDOUT_FILENO)
 341           dup2(pfd[1], STDOUT_FILENO);
 342         if (pfd[1] != STDERR_FILENO)
 343           dup2(pfd[1], STDERR_FILENO);
 344         if (pfd[1] != STDOUT_FILENO && pfd[1] != STDERR_FILENO)
 345           close(pfd[1]);
 346         execvp(argv[optind], argv + optind);
 347
 348         dstr_putf(&d, "%s: couldn't run `%s': %s\n",
 349                   QUIS, argv[optind], strerror(errno));
 350         write(STDERR_FILENO, d.buf, d.len);
 351         dstr_destroy(&d);
 352         _exit(127);
 353       }
 354
 355       sigprocmask(SIG_SETMASK, &oldmask, 0);
 356       fd = pfd[0];
 357       close(pfd[1]);
 358     }
 359   }
 360
 361   {
 362     int f = fcntl(fd, F_GETFL);
 363     fcntl(fd, F_SETFL, f | O_NONBLOCK);
 364   }
 365
 366   gdk_input_add(fd, GDK_INPUT_READ, ready, 0);
 367   gtk_main();
 368   return (status);
 369 }
 370
 371 /*----- That's all, folks -------------------------------------------------*/