src/xrdb.c

   1 /* Deal with the X Resource Manager.
   2    Copyright (C) 1990, 1993-1994, 2000-2015 Free Software Foundation,
   3    Inc.
   4
   5 Author: Joseph Arceneaux
   6 Created: 4/90
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software: you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation, either version 3 of the License, or
  13 (at your option) any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #include <config.h>
  24
  25 #include <unistd.h>
  26 #include <errno.h>
  27 #include <epaths.h>
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30
  31 #include "lisp.h"
  32
  33 /* This may include sys/types.h, and that somehow loses
  34    if this is not done before the other system files.  */
  35 #include "xterm.h"
  36
  37 #include <X11/Xlib.h>
  38 #include <X11/Xatom.h>
  39 #include <X11/X.h>
  40 #include <X11/Xutil.h>
  41 #include <X11/Xresource.h>
  42 #ifdef HAVE_PWD_H
  43 #include <pwd.h>
  44 #endif
  45
  46 #ifdef USE_MOTIF
  47 /* For Vdouble_click_time.  */
  48 #include "keyboard.h"
  49 #endif
  50
  51 /* X file search path processing.  */
  52
  53
  54 /* The string which gets substituted for the %C escape in XFILESEARCHPATH
  55    and friends, or zero if none was specified.  */
  56 static char *x_customization_string;
  57
  58
  59 /* Return the value of the emacs.customization (Emacs.Customization)
  60    resource, for later use in search path decoding.  If we find no
  61    such resource, return zero.  */
  62 static char *
  63 x_get_customization_string (XrmDatabase db, const char *name,
  64                             const char *class)
  65 {
  66   char *full_name = alloca (strlen (name) + sizeof "customization" + 3);
  67   char *full_class = alloca (strlen (class) + sizeof "Customization" + 3);
  68   char *result;
  69
  70   sprintf (full_name,  "%s.%s", name,  "customization");
  71   sprintf (full_class, "%s.%s", class, "Customization");
  72
  73   result = x_get_string_resource (db, full_name, full_class);
  74   return result ? xstrdup (result) : NULL;
  75 }
  76
  77 /* Expand all the Xt-style %-escapes in STRING, whose length is given
  78    by STRING_LEN.  Here are the escapes we're supposed to recognize:
  79
  80         %N      The value of the application's class name
  81         %T      The value of the type parameter ("app-defaults" in this
  82                 context)
  83         %S      The value of the suffix parameter ("" in this context)
  84         %L      The language string associated with the specified display
  85                 (We use the "LANG" environment variable here, if it's set.)
  86         %l      The language part of the display's language string
  87                 (We treat this just like %L.  If someone can tell us what
  88                  we're really supposed to do, dandy.)
  89         %t      The territory part of the display's language string
  90                 (This never gets used.)
  91         %c      The codeset part of the display's language string
  92                 (This never gets used either.)
  93         %C      The customization string retrieved from the resource
  94                 database associated with display.
  95                 (This is x_customization_string.)
  96
  97    Return the resource database if its file was read successfully, and
  98    refers to %L only when the LANG environment variable is set, or
  99    otherwise provided by X.
 100
 101    ESCAPED_SUFFIX is postpended to STRING if it is non-zero.
 102    %-escapes in ESCAPED_SUFFIX are expanded.
 103
 104    Return NULL otherwise.  */
 105
 106 static XrmDatabase
 107 magic_db (const char *string, ptrdiff_t string_len, const char *class,
 108           const char *escaped_suffix)
 109 {
 110   XrmDatabase db;
 111   char *lang = getenv ("LANG");
 112
 113   ptrdiff_t path_size = 100;
 114   char *path = xmalloc (path_size);
 115   ptrdiff_t path_len = 0;
 116
 117   const char *p = string;
 118
 119   while (p < string + string_len)
 120     {
 121       /* The chunk we're about to stick on the end of result.  */
 122       const char *next = p;
 123       ptrdiff_t next_len = 1;
 124
 125       if (*p == '%')
 126         {
 127           p++;
 128
 129           if (p >= string + string_len)
 130             next_len = 0;
 131           else
 132             switch (*p)
 133               {
 134               case '%':
 135                 next = "%";
 136                 next_len = 1;
 137                 break;
 138
 139               case 'C':
 140                 if (x_customization_string)
 141                   {
 142                     next = x_customization_string;
 143                     next_len = strlen (next);
 144                   }
 145                 else
 146                   next_len = 0;
 147                 break;
 148
 149               case 'N':
 150                 next = class;
 151                 next_len = strlen (class);
 152                 break;
 153
 154               case 'T':
 155                 next = "app-defaults";
 156                 next_len = strlen (next);
 157                 break;
 158
 159               default:
 160               case 'S':
 161                 next_len = 0;
 162                 break;
 163
 164               case 'L':
 165               case 'l':
 166                 if (! lang)
 167                   {
 168                     xfree (path);
 169                     return NULL;
 170                   }
 171
 172                 next = lang;
 173                 next_len = strlen (next);
 174                 break;
 175
 176               case 't':
 177               case 'c':
 178                 xfree (path);
 179                 return NULL;
 180               }
 181         }
 182
 183       /* Do we have room for this component followed by a '\0'?  */
 184       if (path_size - path_len <= next_len)
 185         {
 186           if (min (PTRDIFF_MAX, SIZE_MAX) / 2 - 1 - path_len < next_len)
 187             memory_full (SIZE_MAX);
 188           path_size = (path_len + next_len + 1) * 2;
 189           path = xrealloc (path, path_size);
 190         }
 191
 192       memcpy (path + path_len, next, next_len);
 193       path_len += next_len;
 194
 195       p++;
 196
 197       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 198       if (p >= string + string_len && escaped_suffix)
 199         {
 200           string = escaped_suffix;
 201           string_len = strlen (string);
 202           p = string;
 203           escaped_suffix = NULL;
 204         }
 205     }
 206
 207   path[path_len] = '\0';
 208   db = XrmGetFileDatabase (path);
 209   xfree (path);
 210   return db;
 211 }
 212
 213
 214 static char *
 215 gethomedir (void)
 216 {
 217   struct passwd *pw;
 218   char *ptr;
 219   char *copy;
 220
 221   if ((ptr = getenv ("HOME")) == NULL)
 222     {
 223       if ((ptr = getenv ("LOGNAME")) != NULL
 224           || (ptr = getenv ("USER")) != NULL)
 225         pw = getpwnam (ptr);
 226       else
 227         pw = getpwuid (getuid ());
 228
 229       if (pw)
 230         ptr = pw->pw_dir;
 231     }
 232
 233   if (ptr == NULL)
 234     return xstrdup ("/");
 235
 236   ptrdiff_t len = strlen (ptr);
 237   copy = xmalloc (len + 2);
 238   strcpy (copy + len, "/");
 239   return memcpy (copy, ptr, len);
 240 }
 241
 242
 243 /* Find the first element of SEARCH_PATH which exists and is readable,
 244    after expanding the %-escapes.  Return 0 if we didn't find any, and
 245    the path name of the one we found otherwise.  */
 246
 247 static XrmDatabase
 248 search_magic_path (const char *search_path, const char *class,
 249                    const char *escaped_suffix)
 250 {
 251   const char *s, *p;
 252
 253   for (s = search_path; *s; s = p)
 254     {
 255       for (p = s; *p && *p != ':'; p++)
 256         ;
 257
 258       if (p > s)
 259         {
 260           XrmDatabase db = magic_db (s, p - s, class, escaped_suffix);
 261           if (db)
 262             return db;
 263         }
 264       else if (*p == ':')
 265         {
 266           static char const ns[] = "%N%S";
 267           XrmDatabase db = magic_db (ns, strlen (ns), class, escaped_suffix);
 268           if (db)
 269             return db;
 270         }
 271
 272       if (*p == ':')
 273         p++;
 274     }
 275
 276   return 0;
 277 }
 278 \f
 279 /* Producing databases for individual sources.  */
 280
 281 static XrmDatabase
 282 get_system_app (const char *class)
 283 {
 284   const char *path;
 285
 286   path = getenv ("XFILESEARCHPATH");
 287   if (! path) path = PATH_X_DEFAULTS;
 288
 289   return search_magic_path (path, class, 0);
 290 }
 291
 292
 293 static XrmDatabase
 294 get_fallback (Display *display)
 295 {
 296   return NULL;
 297 }
 298
 299
 300 static XrmDatabase
 301 get_user_app (const char *class)
 302 {
 303   XrmDatabase db = 0;
 304   const char *path;
 305
 306   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 307      names, not directories.  */
 308   path = getenv ("XUSERFILESEARCHPATH");
 309   if (path)
 310     db = search_magic_path (path, class, 0);
 311
 312   if (! db)
 313     {
 314       /* Check for APPLRESDIR; it is a path of directories.  In each,
 315          we have to search for LANG/CLASS and then CLASS.  */
 316       path = getenv ("XAPPLRESDIR");
 317       if (path)
 318         {
 319           db = search_magic_path (path, class, "/%L/%N");
 320           if (!db)
 321             db = search_magic_path (path, class, "/%N");
 322         }
 323     }
 324
 325   if (! db)
 326     {
 327       /* Check in the home directory.  This is a bit of a hack; let's
 328          hope one's home directory doesn't contain any %-escapes.  */
 329       char *home = gethomedir ();
 330       db = search_magic_path (home, class, "%L/%N");
 331       if (! db)
 332         db = search_magic_path (home, class, "%N");
 333       xfree (home);
 334     }
 335
 336   return db;
 337 }
 338
 339 static char const xdefaults[] = ".Xdefaults";
 340
 341 static XrmDatabase
 342 get_user_db (Display *display)
 343 {
 344   XrmDatabase db;
 345   char *xdefs;
 346
 347 #ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
 348   xdefs = XResourceManagerString (display);
 349 #else
 350   xdefs = display->xdefaults;
 351 #endif
 352
 353   if (xdefs != NULL)
 354     db = XrmGetStringDatabase (xdefs);
 355   else
 356     {
 357       char *home = gethomedir ();
 358       ptrdiff_t homelen = strlen (home);
 359       char *filename = xrealloc (home, homelen + sizeof xdefaults);
 360       strcpy (filename + homelen, xdefaults);
 361       db = XrmGetFileDatabase (filename);
 362       xfree (filename);
 363     }
 364
 365 #ifdef HAVE_XSCREENRESOURCESTRING
 366   /* Get the screen-specific resources too.  */
 367   xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
 368   if (xdefs != NULL)
 369     {
 370       XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
 371       XFree (xdefs);
 372     }
 373 #endif
 374
 375   return db;
 376 }
 377
 378 static XrmDatabase
 379 get_environ_db (void)
 380 {
 381   XrmDatabase db;
 382   char *p = getenv ("XENVIRONMENT");
 383   char *filename = 0;
 384
 385   if (!p)
 386     {
 387       char *home = gethomedir ();
 388       ptrdiff_t homelen = strlen (home);
 389       Lisp_Object system_name = Fsystem_name ();
 390       ptrdiff_t filenamesize = (homelen + sizeof xdefaults
 391                                 + SBYTES (system_name));
 392       p = filename = xrealloc (home, filenamesize);
 393       lispstpcpy (stpcpy (filename + homelen, xdefaults), system_name);
 394     }
 395
 396   db = XrmGetFileDatabase (p);
 397
 398   xfree (filename);
 399
 400   return db;
 401 }
 402 \f
 403 /* External interface.  */
 404
 405 /* Types of values that we can find in a database */
 406
 407 #define XrmStringType "String"  /* String representation */
 408 static XrmRepresentation x_rm_string;   /* Quark representation */
 409
 410 /* Load X resources based on the display and a possible -xrm option. */
 411
 412 XrmDatabase
 413 x_load_resources (Display *display, const char *xrm_string,
 414                   const char *myname, const char *myclass)
 415 {
 416   XrmDatabase user_database;
 417   XrmDatabase rdb;
 418   XrmDatabase db;
 419   char line[256];
 420
 421 #if defined USE_MOTIF || !defined HAVE_XFT || !defined USE_LUCID
 422   const char *helv = "-*-helvetica-medium-r-*--*-120-*-*-*-*-iso8859-1";
 423 #endif
 424
 425 #ifdef USE_MOTIF
 426   const char *courier = "-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1";
 427 #endif
 428
 429   x_rm_string = XrmStringToQuark (XrmStringType);
 430 #ifndef USE_X_TOOLKIT
 431   /* pmr@osf.org says this shouldn't be done if USE_X_TOOLKIT.
 432      I suspect it's because the toolkit version does this elsewhere.  */
 433   XrmInitialize ();
 434 #endif
 435   rdb = XrmGetStringDatabase ("");
 436
 437   /* Add some font defaults.  If the font `helv' doesn't exist, widgets
 438      will use some other default font.  */
 439 #ifdef USE_MOTIF
 440
 441   sprintf (line, "%s.pane.background: grey75", myclass);
 442   XrmPutLineResource (&rdb, line);
 443   sprintf (line, "%s*fontList: %s", myclass, helv);
 444   XrmPutLineResource (&rdb, line);
 445   sprintf (line, "%s*menu*background: grey75", myclass);
 446   XrmPutLineResource (&rdb, line);
 447   sprintf (line, "%s*menubar*background: grey75", myclass);
 448   XrmPutLineResource (&rdb, line);
 449   sprintf (line, "%s*verticalScrollBar.background: grey75", myclass);
 450   XrmPutLineResource (&rdb, line);
 451   sprintf (line, "%s*verticalScrollBar.troughColor: grey75", myclass);
 452   XrmPutLineResource (&rdb, line);
 453   sprintf (line, "%s*horizontalScrollBar.background: grey75", myclass);
 454   XrmPutLineResource (&rdb, line);
 455   sprintf (line, "%s*horizontalScrollBar.troughColor: grey75", myclass);
 456   XrmPutLineResource (&rdb, line);
 457   sprintf (line, "%s.dialog*.background: grey75", myclass);
 458   XrmPutLineResource (&rdb, line);
 459   sprintf (line, "%s*fsb.Text.background: white", myclass);
 460   XrmPutLineResource (&rdb, line);
 461   sprintf (line, "%s*fsb.FilterText.background: white", myclass);
 462   XrmPutLineResource (&rdb, line);
 463   sprintf (line, "%s*fsb*DirList.background: white", myclass);
 464   XrmPutLineResource (&rdb, line);
 465   sprintf (line, "%s*fsb*ItemsList.background: white", myclass);
 466   XrmPutLineResource (&rdb, line);
 467   sprintf (line, "%s*fsb*background: grey75", myclass);
 468   XrmPutLineResource (&rdb, line);
 469   sprintf (line, "%s*fsb.Text.fontList: %s", myclass, courier);
 470   XrmPutLineResource (&rdb, line);
 471   sprintf (line, "%s*fsb.FilterText.fontList: %s", myclass, courier);
 472   XrmPutLineResource (&rdb, line);
 473   sprintf (line, "%s*fsb*ItemsList.fontList: %s", myclass, courier);
 474   XrmPutLineResource (&rdb, line);
 475   sprintf (line, "%s*fsb*DirList.fontList: %s", myclass, courier);
 476   XrmPutLineResource (&rdb, line);
 477
 478   /* Set double click time of list boxes in the file selection
 479      dialog from `double-click-time'.  */
 480   if (INTEGERP (Vdouble_click_time) && XINT (Vdouble_click_time) > 0)
 481     {
 482       sprintf (line, "%s*fsb*DirList.doubleClickInterval: %"pI"d",
 483                myclass, XFASTINT (Vdouble_click_time));
 484       XrmPutLineResource (&rdb, line);
 485       sprintf (line, "%s*fsb*ItemsList.doubleClickInterval: %"pI"d",
 486                myclass, XFASTINT (Vdouble_click_time));
 487       XrmPutLineResource (&rdb, line);
 488     }
 489
 490 #else /* not USE_MOTIF */
 491
 492   sprintf (line, "Emacs.dialog*.background: grey75");
 493   XrmPutLineResource (&rdb, line);
 494 #if !defined (HAVE_XFT) || !defined (USE_LUCID)
 495   sprintf (line, "Emacs.dialog*.font: %s", helv);
 496   XrmPutLineResource (&rdb, line);
 497   sprintf (line, "*XlwMenu*font: %s", helv);
 498   XrmPutLineResource (&rdb, line);
 499 #endif
 500   sprintf (line, "*XlwMenu*background: grey75");
 501   XrmPutLineResource (&rdb, line);
 502   sprintf (line, "Emacs*verticalScrollBar.background: grey75");
 503   XrmPutLineResource (&rdb, line);
 504   sprintf (line, "Emacs*horizontalScrollBar.background: grey75");
 505   XrmPutLineResource (&rdb, line);
 506
 507 #endif /* not USE_MOTIF */
 508
 509   user_database = get_user_db (display);
 510
 511   /* Figure out what the "customization string" is, so we can use it
 512      to decode paths.  */
 513   xfree (x_customization_string);
 514   x_customization_string
 515     = x_get_customization_string (user_database, myname, myclass);
 516
 517   /* Get application system defaults */
 518   db = get_system_app (myclass);
 519   if (db != NULL)
 520     XrmMergeDatabases (db, &rdb);
 521
 522   /* Get Fallback resources */
 523   db = get_fallback (display);
 524   if (db != NULL)
 525     XrmMergeDatabases (db, &rdb);
 526
 527   /* Get application user defaults */
 528   db = get_user_app (myclass);
 529   if (db != NULL)
 530     XrmMergeDatabases (db, &rdb);
 531
 532   /* get User defaults */
 533   if (user_database != NULL)
 534     XrmMergeDatabases (user_database, &rdb);
 535
 536   /* Get Environment defaults. */
 537   db = get_environ_db ();
 538   if (db != NULL)
 539     XrmMergeDatabases (db, &rdb);
 540
 541   /* Last, merge in any specification from the command line. */
 542   if (xrm_string != NULL)
 543     {
 544       db = XrmGetStringDatabase (xrm_string);
 545       if (db != NULL)
 546         XrmMergeDatabases (db, &rdb);
 547     }
 548
 549   return rdb;
 550 }
 551
 552
 553 /* Retrieve the value of the resource specified by NAME with class CLASS
 554    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 555
 556 static int
 557 x_get_resource (XrmDatabase rdb, const char *name, const char *class,
 558                 XrmRepresentation expected_type, XrmValue *ret_value)
 559 {
 560   XrmValue value;
 561   XrmName namelist[100];
 562   XrmClass classlist[100];
 563   XrmRepresentation type;
 564
 565   XrmStringToNameList (name, namelist);
 566   XrmStringToClassList (class, classlist);
 567
 568   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 569       && (type == expected_type))
 570     {
 571       if (type == x_rm_string)
 572         ret_value->addr = (char *) value.addr;
 573       else
 574         memcpy (ret_value->addr, value.addr, ret_value->size);
 575
 576       return value.size;
 577     }
 578
 579   return 0;
 580 }
 581
 582 /* Retrieve the string resource specified by NAME with CLASS from
 583    database RDB. */
 584
 585 char *
 586 x_get_string_resource (XrmDatabase rdb, const char *name, const char *class)
 587 {
 588   XrmValue value;
 589
 590   if (inhibit_x_resources)
 591     /* --quick was passed, so this is a no-op.  */
 592     return NULL;
 593
 594   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 595     return (char *) value.addr;
 596
 597   return 0;
 598 }
 599 \f
 600 /* Stand-alone test facilities.  */
 601
 602 #ifdef TESTRM
 603
 604 typedef char **List;
 605 #define arg_listify(len, list) (list)
 606 #define car(list) (*(list))
 607 #define cdr(list) (list + 1)
 608 #define NIL(list) (! *(list))
 609 #define free_arglist(list)
 610
 611 static List
 612 member (char *elt, List list)
 613 {
 614   List p;
 615
 616   for (p = list; ! NIL (p); p = cdr (p))
 617     if (! strcmp (elt, car (p)))
 618       return p;
 619
 620   return p;
 621 }
 622
 623 static void
 624 fatal (char *msg, char *prog)
 625 {
 626   fprintf (stderr, msg, prog);
 627   exit (1);
 628 }
 629
 630 int
 631 main (int argc, char **argv)
 632 {
 633   Display *display;
 634   char *displayname, *resource_string, *class, *name;
 635   XrmDatabase xdb;
 636   List arg_list, lp;
 637
 638   arg_list = arg_listify (argc, argv);
 639
 640   lp = member ("-d", arg_list);
 641   if (!NIL (lp))
 642     displayname = car (cdr (lp));
 643   else
 644     displayname = "localhost:0.0";
 645
 646   lp = member ("-xrm", arg_list);
 647   resource_string = NIL (lp) ? 0 : car (cdr (lp));
 648
 649   lp = member ("-c", arg_list);
 650   if (! NIL (lp))
 651     class = car (cdr (lp));
 652   else
 653     class = "Emacs";
 654
 655   lp = member ("-n", arg_list);
 656   if (! NIL (lp))
 657     name = car (cdr (lp));
 658   else
 659     name = "emacs";
 660
 661   free_arglist (arg_list);
 662
 663   if (!(display = XOpenDisplay (displayname)))
 664     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 665
 666   xdb = x_load_resources (display, resource_string, name, class);
 667
 668   /* In a real program, you'd want to also do this: */
 669   display->db = xdb;
 670
 671   while (true)
 672     {
 673       char query_name[90];
 674       char query_class[90];
 675
 676       printf ("Name: ");
 677       gets (query_name);
 678
 679       if (strlen (query_name))
 680         {
 681           char *value;
 682
 683           printf ("Class: ");
 684           gets (query_class);
 685
 686           value = x_get_string_resource (xdb, query_name, query_class);
 687
 688           if (value != NULL)
 689             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 690           else
 691             printf ("\tNo Value.\n\n");
 692         }
 693       else
 694         break;
 695     }
 696   printf ("\tExit.\n\n");
 697
 698   XCloseDisplay (display);
 699
 700   return 0;
 701 }
 702 #endif /* TESTRM */