src/xrdb.c

   1 /* Deal with the X Resource Manager.
   2    Copyright (C) 1990, 1993, 1994 Free Software Foundation.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Written by jla, 4/90 */
  22
  23 #ifdef emacs
  24 #include <config.h>
  25 #endif
  26
  27 #include <paths.h>
  28
  29 #include <stdio.h>
  30
  31 #if 1 /* I'd really appreciate it if this code could go away...  -JimB */
  32 /* this avoids lossage in the `dual-universe' headers on AT&T SysV X11 */
  33 #ifdef USG5
  34 #ifndef SYSV
  35 #define SYSV
  36 #endif
  37 #include <unistd.h>
  38 #endif /* USG5 */
  39
  40 #endif /* 1 */
  41
  42 #include <X11/Xlib.h>
  43 #include <X11/Xatom.h>
  44 #if 0
  45 #include <X11/Xos.h>
  46 #endif
  47 #include <X11/X.h>
  48 #include <X11/Xutil.h>
  49 #include <X11/Xresource.h>
  50 #ifdef VMS
  51 #include "vms-pwd.h"
  52 #else
  53 #include <pwd.h>
  54 #endif
  55 #include <sys/stat.h>
  56
  57 #if !defined(S_ISDIR) && defined(S_IFDIR)
  58 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  59 #endif
  60
  61 extern char *getenv ();
  62
  63 /* This does cause trouble on AIX.  I'm going to take the comment at
  64    face value.  */
  65 #if 0
  66 extern short getuid ();         /* If this causes portability problems,
  67                                    I think we should just delete it; it'll
  68                                    default to `int' anyway.  */
  69 #endif
  70
  71 #ifdef DECLARE_GETPWUID_WITH_UID_T
  72 extern struct passwd *getpwuid (uid_t);
  73 extern struct passwd *getpwnam (const char *);
  74 #else
  75 extern struct passwd *getpwuid ();
  76 extern struct passwd *getpwnam ();
  77 #endif
  78
  79 extern char *get_system_name ();
  80
  81 /* Make sure not to #include anything after these definitions.  Let's
  82    not step on anyone's prototypes.  */
  83 #ifdef emacs
  84 #define malloc xmalloc
  85 #define realloc xrealloc
  86 #define free xfree
  87 #endif
  88
  89 char *x_get_string_resource ();
  90 static int file_p ();
  91
  92 \f
  93 /* X file search path processing.  */
  94
  95
  96 /* The string which gets substituted for the %C escape in XFILESEARCHPATH
  97    and friends, or zero if none was specified.  */
  98 char *x_customization_string;
  99
 100
 101 /* Return the value of the emacs.customization (Emacs.Customization)
 102    resource, for later use in search path decoding.  If we find no
 103    such resource, return zero.  */
 104 char *
 105 x_get_customization_string (db, name, class)
 106      XrmDatabase db;
 107      char *name, *class;
 108 {
 109   char *full_name
 110     = (char *) alloca (strlen (name) + sizeof ("customization") + 3);
 111   char *full_class
 112     = (char *) alloca (strlen (class) + sizeof ("Customization") + 3);
 113   char *result;
 114
 115   sprintf (full_name,  "%s.%s", name,  "customization");
 116   sprintf (full_class, "%s.%s", class, "Customization");
 117
 118   result = x_get_string_resource (db, full_name, full_class);
 119
 120   if (result)
 121     {
 122       char *copy = (char *) malloc (strlen (result) + 1);
 123       strcpy (copy, result);
 124       return copy;
 125     }
 126   else
 127     return 0;
 128 }
 129
 130
 131 /* Expand all the Xt-style %-escapes in STRING, whose length is given
 132    by STRING_LEN.  Here are the escapes we're supposed to recognize:
 133
 134         %N      The value of the application's class name
 135         %T      The value of the type parameter ("app-defaults" in this
 136                 context)
 137         %S      The value of the suffix parameter ("" in this context)
 138         %L      The language string associated with the specified display
 139                 (We use the "LANG" environment variable here, if it's set.)
 140         %l      The language part of the display's language string
 141                 (We treat this just like %L.  If someone can tell us what
 142                  we're really supposed to do, dandy.)
 143         %t      The territory part of the display's language string
 144                 (This never gets used.)
 145         %c      The codeset part of the display's language string
 146                 (This never gets used either.)
 147         %C      The customization string retrieved from the resource
 148                 database associated with display.
 149                 (This is x_customization_string.)
 150
 151    Return the expanded file name if it exists and is readable, and
 152    refers to %L only when the LANG environment variable is set, or
 153    otherwise provided by X.
 154
 155    ESCAPED_SUFFIX and SUFFIX are postpended to STRING if they are
 156    non-zero.  %-escapes in ESCAPED_SUFFIX are expanded; STRING is left
 157    alone.
 158
 159    Return NULL otherwise.  */
 160
 161 static char *
 162 magic_file_p (string, string_len, class, escaped_suffix, suffix)
 163      char *string;
 164      int string_len;
 165      char *class, *escaped_suffix, *suffix;
 166 {
 167   char *lang = getenv ("LANG");
 168
 169   int path_size = 100;
 170   char *path = (char *) malloc (path_size);
 171   int path_len = 0;
 172
 173   char *p = string;
 174
 175   while (p < string + string_len)
 176     {
 177       /* The chunk we're about to stick on the end of result.  */
 178       char *next;
 179       int next_len;
 180
 181       if (*p == '%')
 182         {
 183           p++;
 184
 185           if (p >= string + string_len)
 186             next_len = 0;
 187           else
 188             switch (*p)
 189               {
 190               case '%':
 191                 next = "%";
 192                 next_len = 1;
 193                 break;
 194
 195               case 'C':
 196                 next = (x_customization_string
 197                         ? x_customization_string
 198                         : "");
 199                 next_len = strlen (next);
 200                 break;
 201
 202               case 'N':
 203                 next = class;
 204                 next_len = strlen (class);
 205                 break;
 206
 207               case 'T':
 208                 next = "app-defaults";
 209                 next_len = strlen (next);
 210                 break;
 211
 212               default:
 213               case 'S':
 214                 next_len = 0;
 215                 break;
 216
 217               case 'L':
 218               case 'l':
 219                 if (! lang)
 220                   {
 221                     free (path);
 222                     return NULL;
 223                   }
 224
 225                 next = lang;
 226                 next_len = strlen (next);
 227                 break;
 228
 229               case 't':
 230               case 'c':
 231                 free (path);
 232                 return NULL;
 233               }
 234         }
 235       else
 236         next = p, next_len = 1;
 237
 238       /* Do we have room for this component followed by a '\0' ?  */
 239       if (path_len + next_len + 1 > path_size)
 240         {
 241           path_size = (path_len + next_len + 1) * 2;
 242           path = (char *) realloc (path, path_size);
 243         }
 244
 245       bcopy (next, path + path_len, next_len);
 246       path_len += next_len;
 247
 248       p++;
 249
 250       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 251       if (p >= string + string_len && escaped_suffix)
 252         {
 253           string = escaped_suffix;
 254           string_len = strlen (string);
 255           p = string;
 256           escaped_suffix = NULL;
 257         }
 258     }
 259
 260   /* Perhaps we should add the SUFFIX now.  */
 261   if (suffix)
 262     {
 263       int suffix_len = strlen (suffix);
 264
 265       if (path_len + suffix_len + 1 > path_size)
 266         {
 267           path_size = (path_len + suffix_len + 1);
 268           path = (char *) realloc (path, path_size);
 269         }
 270
 271       bcopy (suffix, path + path_len, suffix_len);
 272       path_len += suffix_len;
 273     }
 274
 275   path[path_len] = '\0';
 276
 277   if (! file_p (path))
 278     {
 279       free (path);
 280       return NULL;
 281     }
 282
 283   return path;
 284 }
 285
 286
 287 static char *
 288 gethomedir ()
 289 {
 290   struct passwd *pw;
 291   char *ptr;
 292   char *copy;
 293
 294   if ((ptr = getenv ("HOME")) == NULL)
 295     {
 296       if ((ptr = getenv ("LOGNAME")) != NULL
 297           || (ptr = getenv ("USER")) != NULL)
 298         pw = getpwnam (ptr);
 299       else
 300         pw = getpwuid (getuid ());
 301
 302       if (pw)
 303         ptr = pw->pw_dir;
 304     }
 305
 306   if (ptr == NULL)
 307     return "/";
 308
 309   copy = (char *) malloc (strlen (ptr) + 2);
 310   strcpy (copy, ptr);
 311   strcat (copy, "/");
 312
 313   return copy;
 314 }
 315
 316
 317 static int
 318 file_p (path)
 319      char *path;
 320 {
 321   struct stat status;
 322
 323   return (access (path, 4) == 0                 /* exists and is readable */
 324           && stat (path, &status) == 0          /* get the status */
 325           && (S_ISDIR (status.st_mode)) == 0);  /* not a directory */
 326 }
 327
 328
 329 /* Find the first element of SEARCH_PATH which exists and is readable,
 330    after expanding the %-escapes.  Return 0 if we didn't find any, and
 331    the path name of the one we found otherwise.  */
 332
 333 static char *
 334 search_magic_path (search_path, class, escaped_suffix, suffix)
 335      char *search_path, *class, *escaped_suffix, *suffix;
 336 {
 337   register char *s, *p;
 338
 339   for (s = search_path; *s; s = p)
 340     {
 341       for (p = s; *p && *p != ':'; p++)
 342         ;
 343
 344       if (p > s)
 345         {
 346           char *path = magic_file_p (s, p - s, class, escaped_suffix, suffix);
 347           if (path)
 348             return path;
 349         }
 350       else if (*p == ':')
 351         {
 352           char *path;
 353
 354           s = "%N%S";
 355           path = magic_file_p (s, strlen (s), class, escaped_suffix, suffix);
 356           if (path)
 357             return path;
 358         }
 359
 360       if (*p == ':')
 361         p++;
 362     }
 363
 364   return 0;
 365 }
 366 \f
 367 /* Producing databases for individual sources.  */
 368
 369 static XrmDatabase
 370 get_system_app (class)
 371      char *class;
 372 {
 373   XrmDatabase db = NULL;
 374   char *path;
 375
 376   path = getenv ("XFILESEARCHPATH");
 377   if (! path) path = PATH_X_DEFAULTS;
 378
 379   path = search_magic_path (path, class, 0, 0);
 380   if (path)
 381     {
 382       db = XrmGetFileDatabase (path);
 383       free (path);
 384     }
 385
 386   return db;
 387 }
 388
 389
 390 static XrmDatabase
 391 get_fallback (display)
 392      Display *display;
 393 {
 394   XrmDatabase db;
 395
 396   return NULL;
 397 }
 398
 399
 400 static XrmDatabase
 401 get_user_app (class)
 402      char *class;
 403 {
 404   char *path;
 405   char *file = 0;
 406   char *free_it = 0;
 407
 408   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 409      names, not directories.  */
 410   if (((path = getenv ("XUSERFILESEARCHPATH"))
 411        && (file = search_magic_path (path, class, 0, 0)))
 412
 413       /* Check for APPLRESDIR; it is a path of directories.  In each,
 414          we have to search for LANG/CLASS and then CLASS.  */
 415       || ((path = getenv ("XAPPLRESDIR"))
 416           && ((file = search_magic_path (path, class, "/%L/%N", 0))
 417               || (file = search_magic_path (path, class, "/%N", 0))))
 418
 419       /* Check in the home directory.  This is a bit of a hack; let's
 420          hope one's home directory doesn't contain any %-escapes.  */
 421       || (free_it = gethomedir (),
 422           ((file = search_magic_path (free_it, class, "%L/%N", 0))
 423            || (file = search_magic_path (free_it, class, "%N", 0)))))
 424     {
 425       XrmDatabase db = XrmGetFileDatabase (file);
 426       free (file);
 427       if (free_it)
 428         free (free_it);
 429       return db;
 430     }
 431
 432   if (free_it)
 433     free (free_it);
 434   return NULL;
 435 }
 436
 437
 438 static XrmDatabase
 439 get_user_db (display)
 440      Display *display;
 441 {
 442   XrmDatabase db;
 443   char *xdefs;
 444
 445 #ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
 446   xdefs = XResourceManagerString (display);
 447 #else
 448   xdefs = display->xdefaults;
 449 #endif
 450
 451   if (xdefs != NULL)
 452     db = XrmGetStringDatabase (xdefs);
 453   else
 454     {
 455       char *home;
 456       char *xdefault;
 457
 458       home = gethomedir ();
 459       xdefault = (char *) malloc (strlen (home) + sizeof (".Xdefaults"));
 460       strcpy (xdefault, home);
 461       strcat (xdefault, ".Xdefaults");
 462       db = XrmGetFileDatabase (xdefault);
 463       free (home);
 464       free (xdefault);
 465     }
 466
 467 #ifdef HAVE_XSCREENRESOURCESTRING
 468   /* Get the screen-specific resources too.  */
 469   xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
 470   if (xdefs != NULL)
 471     {
 472       XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
 473       XFree (xdefs);
 474     }
 475 #endif
 476
 477   return db;
 478 }
 479
 480 static XrmDatabase
 481 get_environ_db ()
 482 {
 483   XrmDatabase db;
 484   char *p;
 485   char *path = 0, *home = 0, *host;
 486
 487   if ((p = getenv ("XENVIRONMENT")) == NULL)
 488     {
 489       home = gethomedir ();
 490       host = get_system_name ();
 491       path = (char *) malloc (strlen (home)
 492                               + sizeof (".Xdefaults-")
 493                               + strlen (host));
 494       sprintf (path, "%s%s%s", home, ".Xdefaults-", host);
 495       p = path;
 496     }
 497
 498   db = XrmGetFileDatabase (p);
 499
 500   if (path) free (path);
 501   if (home) free (home);
 502
 503   return db;
 504 }
 505 \f
 506 /* External interface.  */
 507
 508 /* Types of values that we can find in a database */
 509
 510 #define XrmStringType "String"  /* String representation */
 511 XrmRepresentation x_rm_string;  /* Quark representation */
 512
 513 /* Load X resources based on the display and a possible -xrm option. */
 514
 515 XrmDatabase
 516 x_load_resources (display, xrm_string, myname, myclass)
 517      Display *display;
 518      char *xrm_string, *myname, *myclass;
 519 {
 520   char *xdefs;
 521   XrmDatabase user_database;
 522   XrmDatabase rdb;
 523   XrmDatabase db;
 524
 525   x_rm_string = XrmStringToQuark (XrmStringType);
 526 #ifndef USE_X_TOOLKIT
 527   /* pmr@osf.org says this shouldn't be done if USE_X_TOOLKIT.
 528      I suspect it's because the toolkit version does this elsewhere.  */
 529   XrmInitialize ();
 530 #endif
 531   rdb = XrmGetStringDatabase ("");
 532
 533   user_database = get_user_db (display);
 534
 535   /* Figure out what the "customization string" is, so we can use it
 536      to decode paths.  */
 537   if (x_customization_string)
 538     free (x_customization_string);
 539   x_customization_string
 540     = x_get_customization_string (user_database, myname, myclass);
 541
 542   /* Get application system defaults */
 543   db = get_system_app (myclass);
 544   if (db != NULL)
 545     XrmMergeDatabases (db, &rdb);
 546
 547   /* Get Fallback resources */
 548   db = get_fallback (display);
 549   if (db != NULL)
 550     XrmMergeDatabases (db, &rdb);
 551
 552   /* Get application user defaults */
 553   db = get_user_app (myclass);
 554   if (db != NULL)
 555     XrmMergeDatabases (db, &rdb);
 556
 557   /* get User defaults */
 558   if (user_database != NULL)
 559     XrmMergeDatabases (user_database, &rdb);
 560
 561   /* Get Environment defaults. */
 562   db = get_environ_db ();
 563   if (db != NULL)
 564     XrmMergeDatabases (db, &rdb);
 565
 566   /* Last, merge in any specification from the command line. */
 567   if (xrm_string != NULL)
 568     {
 569       db = XrmGetStringDatabase (xrm_string);
 570       if (db != NULL)
 571         XrmMergeDatabases (db, &rdb);
 572     }
 573
 574   return rdb;
 575 }
 576
 577
 578 /* Retrieve the value of the resource specified by NAME with class CLASS
 579    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 580
 581 int
 582 x_get_resource (rdb, name, class, expected_type, ret_value)
 583      XrmDatabase rdb;
 584      char *name, *class;
 585      XrmRepresentation expected_type;
 586      XrmValue *ret_value;
 587 {
 588   XrmValue value;
 589   XrmName namelist[100];
 590   XrmClass classlist[100];
 591   XrmRepresentation type;
 592
 593   XrmStringToNameList(name, namelist);
 594   XrmStringToClassList(class, classlist);
 595
 596   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 597       && (type == expected_type))
 598     {
 599       if (type == x_rm_string)
 600         ret_value->addr = (char *) value.addr;
 601       else
 602         bcopy (value.addr, ret_value->addr, ret_value->size);
 603
 604       return value.size;
 605     }
 606
 607   return 0;
 608 }
 609
 610 /* Retrieve the string resource specified by NAME with CLASS from
 611    database RDB. */
 612
 613 char *
 614 x_get_string_resource (rdb, name, class)
 615      XrmDatabase rdb;
 616      char *name, *class;
 617 {
 618   XrmValue value;
 619
 620   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 621     return (char *) value.addr;
 622
 623   return (char *) 0;
 624 }
 625 \f
 626 /* Stand-alone test facilities.  */
 627
 628 #ifdef TESTRM
 629
 630 typedef char **List;
 631 #define arg_listify(len, list) (list)
 632 #define car(list) (*(list))
 633 #define cdr(list) (list + 1)
 634 #define NIL(list) (! *(list))
 635 #define free_arglist(list)
 636
 637 static List
 638 member (elt, list)
 639      char *elt;
 640      List list;
 641 {
 642   List p;
 643
 644   for (p = list; ! NIL (p); p = cdr (p))
 645     if (! strcmp (elt, car (p)))
 646       return p;
 647
 648   return p;
 649 }
 650
 651 static void
 652 fatal (msg, prog, x1, x2, x3, x4, x5)
 653     char *msg, *prog;
 654     int x1, x2, x3, x4, x5;
 655 {
 656     extern int errno;
 657
 658     if (errno)
 659       perror (prog);
 660
 661     (void) fprintf (stderr, msg, prog, x1, x2, x3, x4, x5);
 662     exit (1);
 663 }
 664
 665 main (argc, argv)
 666     int argc;
 667     char **argv;
 668 {
 669   Display *display;
 670   char *displayname, *resource_string, *class, *name;
 671   XrmDatabase xdb;
 672   List arg_list, lp;
 673
 674   arg_list = arg_listify (argc, argv);
 675
 676   lp = member ("-d", arg_list);
 677   if (!NIL (lp))
 678     displayname = car (cdr (lp));
 679   else
 680     displayname = "localhost:0.0";
 681
 682   lp = member ("-xrm", arg_list);
 683   if (! NIL (lp))
 684     resource_string = car (cdr (lp));
 685   else
 686     resource_string = (char *) 0;
 687
 688   lp = member ("-c", arg_list);
 689   if (! NIL (lp))
 690     class = car (cdr (lp));
 691   else
 692     class = "Emacs";
 693
 694   lp = member ("-n", arg_list);
 695   if (! NIL (lp))
 696     name = car (cdr (lp));
 697   else
 698     name = "emacs";
 699
 700   free_arglist (arg_list);
 701
 702   if (!(display = XOpenDisplay (displayname)))
 703     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 704
 705   xdb = x_load_resources (display, resource_string, name, class);
 706
 707   /* In a real program, you'd want to also do this: */
 708   display->db = xdb;
 709
 710   while (1)
 711     {
 712       char query_name[90];
 713       char query_class[90];
 714
 715       printf ("Name: ");
 716       gets (query_name);
 717
 718       if (strlen (query_name))
 719         {
 720           char *value;
 721
 722           printf ("Class: ");
 723           gets (query_class);
 724
 725           value = x_get_string_resource (xdb, query_name, query_class);
 726
 727           if (value != NULL)
 728             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 729           else
 730             printf ("\tNo Value.\n\n");
 731         }
 732       else
 733         break;
 734     }
 735   printf ("\tExit.\n\n");
 736
 737   XCloseDisplay (display);
 738 }
 739 #endif /* TESTRM */