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 = NULL;
 123       ptrdiff_t next_len;
 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                 next = (x_customization_string
 141                         ? x_customization_string
 142                         : "");
 143                 next_len = strlen (next);
 144                 break;
 145
 146               case 'N':
 147                 next = class;
 148                 next_len = strlen (class);
 149                 break;
 150
 151               case 'T':
 152                 next = "app-defaults";
 153                 next_len = strlen (next);
 154                 break;
 155
 156               default:
 157               case 'S':
 158                 next_len = 0;
 159                 break;
 160
 161               case 'L':
 162               case 'l':
 163                 if (! lang)
 164                   {
 165                     xfree (path);
 166                     return NULL;
 167                   }
 168
 169                 next = lang;
 170                 next_len = strlen (next);
 171                 break;
 172
 173               case 't':
 174               case 'c':
 175                 xfree (path);
 176                 return NULL;
 177               }
 178         }
 179       else
 180         next = p, next_len = 1;
 181
 182       /* Do we have room for this component followed by a '\0'?  */
 183       if (path_size - path_len <= next_len)
 184         {
 185           if (min (PTRDIFF_MAX, SIZE_MAX) / 2 - 1 - path_len < next_len)
 186             memory_full (SIZE_MAX);
 187           path_size = (path_len + next_len + 1) * 2;
 188           path = xrealloc (path, path_size);
 189         }
 190
 191       memcpy (path + path_len, next, next_len);
 192       path_len += next_len;
 193
 194       p++;
 195
 196       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 197       if (p >= string + string_len && escaped_suffix)
 198         {
 199           string = escaped_suffix;
 200           string_len = strlen (string);
 201           p = string;
 202           escaped_suffix = NULL;
 203         }
 204     }
 205
 206   path[path_len] = '\0';
 207   db = XrmGetFileDatabase (path);
 208   xfree (path);
 209   return db;
 210 }
 211
 212
 213 static char *
 214 gethomedir (void)
 215 {
 216   struct passwd *pw;
 217   char *ptr;
 218   char *copy;
 219
 220   if ((ptr = getenv ("HOME")) == NULL)
 221     {
 222       if ((ptr = getenv ("LOGNAME")) != NULL
 223           || (ptr = getenv ("USER")) != NULL)
 224         pw = getpwnam (ptr);
 225       else
 226         pw = getpwuid (getuid ());
 227
 228       if (pw)
 229         ptr = pw->pw_dir;
 230     }
 231
 232   if (ptr == NULL)
 233     return xstrdup ("/");
 234
 235   ptrdiff_t len = strlen (ptr);
 236   copy = xmalloc (len + 2);
 237   strcpy (copy + len, "/");
 238   return memcpy (copy, ptr, len);
 239 }
 240
 241
 242 /* Find the first element of SEARCH_PATH which exists and is readable,
 243    after expanding the %-escapes.  Return 0 if we didn't find any, and
 244    the path name of the one we found otherwise.  */
 245
 246 static XrmDatabase
 247 search_magic_path (const char *search_path, const char *class,
 248                    const char *escaped_suffix)
 249 {
 250   const char *s, *p;
 251
 252   for (s = search_path; *s; s = p)
 253     {
 254       for (p = s; *p && *p != ':'; p++)
 255         ;
 256
 257       if (p > s)
 258         {
 259           XrmDatabase db = magic_db (s, p - s, class, escaped_suffix);
 260           if (db)
 261             return db;
 262         }
 263       else if (*p == ':')
 264         {
 265           static char const ns[] = "%N%S";
 266           XrmDatabase db = magic_db (ns, strlen (ns), class, escaped_suffix);
 267           if (db)
 268             return db;
 269         }
 270
 271       if (*p == ':')
 272         p++;
 273     }
 274
 275   return 0;
 276 }
 277 \f
 278 /* Producing databases for individual sources.  */
 279
 280 static XrmDatabase
 281 get_system_app (const char *class)
 282 {
 283   const char *path;
 284
 285   path = getenv ("XFILESEARCHPATH");
 286   if (! path) path = PATH_X_DEFAULTS;
 287
 288   return search_magic_path (path, class, 0);
 289 }
 290
 291
 292 static XrmDatabase
 293 get_fallback (Display *display)
 294 {
 295   return NULL;
 296 }
 297
 298
 299 static XrmDatabase
 300 get_user_app (const char *class)
 301 {
 302   XrmDatabase db = 0;
 303   const char *path;
 304
 305   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 306      names, not directories.  */
 307   path = getenv ("XUSERFILESEARCHPATH");
 308   if (path)
 309     db = search_magic_path (path, class, 0);
 310
 311   if (! db)
 312     {
 313       /* Check for APPLRESDIR; it is a path of directories.  In each,
 314          we have to search for LANG/CLASS and then CLASS.  */
 315       path = getenv ("XAPPLRESDIR");
 316       if (path)
 317         {
 318           db = search_magic_path (path, class, "/%L/%N");
 319           if (!db)
 320             db = search_magic_path (path, class, "/%N");
 321         }
 322     }
 323
 324   if (! db)
 325     {
 326       /* Check in the home directory.  This is a bit of a hack; let's
 327          hope one's home directory doesn't contain any %-escapes.  */
 328       char *home = gethomedir ();
 329       db = search_magic_path (home, class, "%L/%N");
 330       if (! db)
 331         db = search_magic_path (home, class, "%N");
 332       xfree (home);
 333     }
 334
 335   return db;
 336 }
 337
 338 static char const xdefaults[] = ".Xdefaults";
 339
 340 static XrmDatabase
 341 get_user_db (Display *display)
 342 {
 343   XrmDatabase db;
 344   char *xdefs;
 345
 346 #ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
 347   xdefs = XResourceManagerString (display);
 348 #else
 349   xdefs = display->xdefaults;
 350 #endif
 351
 352   if (xdefs != NULL)
 353     db = XrmGetStringDatabase (xdefs);
 354   else
 355     {
 356       char *home = gethomedir ();
 357       ptrdiff_t homelen = strlen (home);
 358       char *filename = xrealloc (home, homelen + sizeof xdefaults);
 359       strcpy (filename + homelen, xdefaults);
 360       db = XrmGetFileDatabase (filename);
 361       xfree (filename);
 362     }
 363
 364 #ifdef HAVE_XSCREENRESOURCESTRING
 365   /* Get the screen-specific resources too.  */
 366   xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
 367   if (xdefs != NULL)
 368     {
 369       XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
 370       XFree (xdefs);
 371     }
 372 #endif
 373
 374   return db;
 375 }
 376
 377 static XrmDatabase
 378 get_environ_db (void)
 379 {
 380   XrmDatabase db;
 381   char *p = getenv ("XENVIRONMENT");
 382   char *filename = 0;
 383
 384   if (!p)
 385     {
 386       char *home = gethomedir ();
 387       ptrdiff_t homelen = strlen (home);
 388       Lisp_Object system_name = Fsystem_name ();
 389       ptrdiff_t filenamesize = (homelen + sizeof xdefaults
 390                                 + SBYTES (system_name));
 391       p = filename = xrealloc (home, filenamesize);
 392       lispstpcpy (stpcpy (filename + homelen, xdefaults), system_name);
 393     }
 394
 395   db = XrmGetFileDatabase (p);
 396
 397   xfree (filename);
 398
 399   return db;
 400 }
 401 \f
 402 /* External interface.  */
 403
 404 /* Types of values that we can find in a database */
 405
 406 #define XrmStringType "String"  /* String representation */
 407 static XrmRepresentation x_rm_string;   /* Quark representation */
 408
 409 /* Load X resources based on the display and a possible -xrm option. */
 410
 411 XrmDatabase
 412 x_load_resources (Display *display, const char *xrm_string,
 413                   const char *myname, const char *myclass)
 414 {
 415   XrmDatabase user_database;
 416   XrmDatabase rdb;
 417   XrmDatabase db;
 418   char line[256];
 419
 420 #if defined USE_MOTIF || !defined HAVE_XFT || !defined USE_LUCID
 421   const char *helv = "-*-helvetica-medium-r-*--*-120-*-*-*-*-iso8859-1";
 422 #endif
 423
 424 #ifdef USE_MOTIF
 425   const char *courier = "-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1";
 426 #endif
 427
 428   x_rm_string = XrmStringToQuark (XrmStringType);
 429 #ifndef USE_X_TOOLKIT
 430   /* pmr@osf.org says this shouldn't be done if USE_X_TOOLKIT.
 431      I suspect it's because the toolkit version does this elsewhere.  */
 432   XrmInitialize ();
 433 #endif
 434   rdb = XrmGetStringDatabase ("");
 435
 436   /* Add some font defaults.  If the font `helv' doesn't exist, widgets
 437      will use some other default font.  */
 438 #ifdef USE_MOTIF
 439
 440   sprintf (line, "%s.pane.background: grey75", myclass);
 441   XrmPutLineResource (&rdb, line);
 442   sprintf (line, "%s*fontList: %s", myclass, helv);
 443   XrmPutLineResource (&rdb, line);
 444   sprintf (line, "%s*menu*background: grey75", myclass);
 445   XrmPutLineResource (&rdb, line);
 446   sprintf (line, "%s*menubar*background: grey75", myclass);
 447   XrmPutLineResource (&rdb, line);
 448   sprintf (line, "%s*verticalScrollBar.background: grey75", myclass);
 449   XrmPutLineResource (&rdb, line);
 450   sprintf (line, "%s*verticalScrollBar.troughColor: grey75", myclass);
 451   XrmPutLineResource (&rdb, line);
 452   sprintf (line, "%s*horizontalScrollBar.background: grey75", myclass);
 453   XrmPutLineResource (&rdb, line);
 454   sprintf (line, "%s*horizontalScrollBar.troughColor: grey75", myclass);
 455   XrmPutLineResource (&rdb, line);
 456   sprintf (line, "%s.dialog*.background: grey75", myclass);
 457   XrmPutLineResource (&rdb, line);
 458   sprintf (line, "%s*fsb.Text.background: white", myclass);
 459   XrmPutLineResource (&rdb, line);
 460   sprintf (line, "%s*fsb.FilterText.background: white", myclass);
 461   XrmPutLineResource (&rdb, line);
 462   sprintf (line, "%s*fsb*DirList.background: white", myclass);
 463   XrmPutLineResource (&rdb, line);
 464   sprintf (line, "%s*fsb*ItemsList.background: white", myclass);
 465   XrmPutLineResource (&rdb, line);
 466   sprintf (line, "%s*fsb*background: grey75", myclass);
 467   XrmPutLineResource (&rdb, line);
 468   sprintf (line, "%s*fsb.Text.fontList: %s", myclass, courier);
 469   XrmPutLineResource (&rdb, line);
 470   sprintf (line, "%s*fsb.FilterText.fontList: %s", myclass, courier);
 471   XrmPutLineResource (&rdb, line);
 472   sprintf (line, "%s*fsb*ItemsList.fontList: %s", myclass, courier);
 473   XrmPutLineResource (&rdb, line);
 474   sprintf (line, "%s*fsb*DirList.fontList: %s", myclass, courier);
 475   XrmPutLineResource (&rdb, line);
 476
 477   /* Set double click time of list boxes in the file selection
 478      dialog from `double-click-time'.  */
 479   if (INTEGERP (Vdouble_click_time) && XINT (Vdouble_click_time) > 0)
 480     {
 481       sprintf (line, "%s*fsb*DirList.doubleClickInterval: %"pI"d",
 482                myclass, XFASTINT (Vdouble_click_time));
 483       XrmPutLineResource (&rdb, line);
 484       sprintf (line, "%s*fsb*ItemsList.doubleClickInterval: %"pI"d",
 485                myclass, XFASTINT (Vdouble_click_time));
 486       XrmPutLineResource (&rdb, line);
 487     }
 488
 489 #else /* not USE_MOTIF */
 490
 491   sprintf (line, "Emacs.dialog*.background: grey75");
 492   XrmPutLineResource (&rdb, line);
 493 #if !defined (HAVE_XFT) || !defined (USE_LUCID)
 494   sprintf (line, "Emacs.dialog*.font: %s", helv);
 495   XrmPutLineResource (&rdb, line);
 496   sprintf (line, "*XlwMenu*font: %s", helv);
 497   XrmPutLineResource (&rdb, line);
 498 #endif
 499   sprintf (line, "*XlwMenu*background: grey75");
 500   XrmPutLineResource (&rdb, line);
 501   sprintf (line, "Emacs*verticalScrollBar.background: grey75");
 502   XrmPutLineResource (&rdb, line);
 503   sprintf (line, "Emacs*horizontalScrollBar.background: grey75");
 504   XrmPutLineResource (&rdb, line);
 505
 506 #endif /* not USE_MOTIF */
 507
 508   user_database = get_user_db (display);
 509
 510   /* Figure out what the "customization string" is, so we can use it
 511      to decode paths.  */
 512   xfree (x_customization_string);
 513   x_customization_string
 514     = x_get_customization_string (user_database, myname, myclass);
 515
 516   /* Get application system defaults */
 517   db = get_system_app (myclass);
 518   if (db != NULL)
 519     XrmMergeDatabases (db, &rdb);
 520
 521   /* Get Fallback resources */
 522   db = get_fallback (display);
 523   if (db != NULL)
 524     XrmMergeDatabases (db, &rdb);
 525
 526   /* Get application user defaults */
 527   db = get_user_app (myclass);
 528   if (db != NULL)
 529     XrmMergeDatabases (db, &rdb);
 530
 531   /* get User defaults */
 532   if (user_database != NULL)
 533     XrmMergeDatabases (user_database, &rdb);
 534
 535   /* Get Environment defaults. */
 536   db = get_environ_db ();
 537   if (db != NULL)
 538     XrmMergeDatabases (db, &rdb);
 539
 540   /* Last, merge in any specification from the command line. */
 541   if (xrm_string != NULL)
 542     {
 543       db = XrmGetStringDatabase (xrm_string);
 544       if (db != NULL)
 545         XrmMergeDatabases (db, &rdb);
 546     }
 547
 548   return rdb;
 549 }
 550
 551
 552 /* Retrieve the value of the resource specified by NAME with class CLASS
 553    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 554
 555 static int
 556 x_get_resource (XrmDatabase rdb, const char *name, const char *class,
 557                 XrmRepresentation expected_type, XrmValue *ret_value)
 558 {
 559   XrmValue value;
 560   XrmName namelist[100];
 561   XrmClass classlist[100];
 562   XrmRepresentation type;
 563
 564   XrmStringToNameList (name, namelist);
 565   XrmStringToClassList (class, classlist);
 566
 567   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 568       && (type == expected_type))
 569     {
 570       if (type == x_rm_string)
 571         ret_value->addr = (char *) value.addr;
 572       else
 573         memcpy (ret_value->addr, value.addr, ret_value->size);
 574
 575       return value.size;
 576     }
 577
 578   return 0;
 579 }
 580
 581 /* Retrieve the string resource specified by NAME with CLASS from
 582    database RDB. */
 583
 584 char *
 585 x_get_string_resource (XrmDatabase rdb, const char *name, const char *class)
 586 {
 587   XrmValue value;
 588
 589   if (inhibit_x_resources)
 590     /* --quick was passed, so this is a no-op.  */
 591     return NULL;
 592
 593   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 594     return (char *) value.addr;
 595
 596   return 0;
 597 }
 598 \f
 599 /* Stand-alone test facilities.  */
 600
 601 #ifdef TESTRM
 602
 603 typedef char **List;
 604 #define arg_listify(len, list) (list)
 605 #define car(list) (*(list))
 606 #define cdr(list) (list + 1)
 607 #define NIL(list) (! *(list))
 608 #define free_arglist(list)
 609
 610 static List
 611 member (char *elt, List list)
 612 {
 613   List p;
 614
 615   for (p = list; ! NIL (p); p = cdr (p))
 616     if (! strcmp (elt, car (p)))
 617       return p;
 618
 619   return p;
 620 }
 621
 622 static void
 623 fatal (char *msg, char *prog)
 624 {
 625   fprintf (stderr, msg, prog);
 626   exit (1);
 627 }
 628
 629 int
 630 main (int argc, char **argv)
 631 {
 632   Display *display;
 633   char *displayname, *resource_string, *class, *name;
 634   XrmDatabase xdb;
 635   List arg_list, lp;
 636
 637   arg_list = arg_listify (argc, argv);
 638
 639   lp = member ("-d", arg_list);
 640   if (!NIL (lp))
 641     displayname = car (cdr (lp));
 642   else
 643     displayname = "localhost:0.0";
 644
 645   lp = member ("-xrm", arg_list);
 646   resource_string = NIL (lp) ? 0 : car (cdr (lp));
 647
 648   lp = member ("-c", arg_list);
 649   if (! NIL (lp))
 650     class = car (cdr (lp));
 651   else
 652     class = "Emacs";
 653
 654   lp = member ("-n", arg_list);
 655   if (! NIL (lp))
 656     name = car (cdr (lp));
 657   else
 658     name = "emacs";
 659
 660   free_arglist (arg_list);
 661
 662   if (!(display = XOpenDisplay (displayname)))
 663     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 664
 665   xdb = x_load_resources (display, resource_string, name, class);
 666
 667   /* In a real program, you'd want to also do this: */
 668   display->db = xdb;
 669
 670   while (true)
 671     {
 672       char query_name[90];
 673       char query_class[90];
 674
 675       printf ("Name: ");
 676       gets (query_name);
 677
 678       if (strlen (query_name))
 679         {
 680           char *value;
 681
 682           printf ("Class: ");
 683           gets (query_class);
 684
 685           value = x_get_string_resource (xdb, query_name, query_class);
 686
 687           if (value != NULL)
 688             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 689           else
 690             printf ("\tNo Value.\n\n");
 691         }
 692       else
 693         break;
 694     }
 695   printf ("\tExit.\n\n");
 696
 697   XCloseDisplay (display);
 698
 699   return 0;
 700 }
 701 #endif /* TESTRM */