src/xrdb.c

   1 /* Deal with the X Resource Manager.
   2    Copyright (C) 1990, 1993, 1994 Free Software Foundation.
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation; either version 2, or (at your option)
   7 any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; see the file COPYING.  If not, write to
  16 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 /* Written by jla, 4/90 */
  19
  20 #ifdef emacs
  21 #include <config.h>
  22 #endif
  23
  24 #include <stdio.h>
  25
  26 #if 1 /* I'd really appreciate it if this code could go away...  -JimB */
  27 /* this avoids lossage in the `dual-universe' headers on AT&T SysV X11 */
  28 #ifdef USG5
  29 #ifndef SYSV
  30 #define SYSV
  31 #endif
  32 #include <unistd.h>
  33 #endif /* USG5 */
  34
  35 #endif /* 1 */
  36
  37 #include <X11/Xlib.h>
  38 #include <X11/Xatom.h>
  39 #if 0
  40 #include <X11/Xos.h>
  41 #endif
  42 #include <X11/X.h>
  43 #include <X11/Xutil.h>
  44 #include <X11/Xresource.h>
  45 #ifdef VMS
  46 #include "vms-pwd.h"
  47 #else
  48 #include <pwd.h>
  49 #endif
  50 #include <sys/stat.h>
  51
  52 #if !defined(S_ISDIR) && defined(S_IFDIR)
  53 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  54 #endif
  55
  56 extern char *getenv ();
  57
  58 /* This does cause trouble on AIX.  I'm going to take the comment at
  59    face value.  */
  60 #if 0
  61 extern short getuid ();         /* If this causes portability problems,
  62                                    I think we should just delete it; it'll
  63                                    default to `int' anyway.  */
  64 #endif
  65
  66 #ifdef DECLARE_GETPWUID_WITH_UID_T
  67 extern struct passwd *getpwuid (uid_t);
  68 extern struct passwd *getpwnam (const char *);
  69 #else
  70 extern struct passwd *getpwuid ();
  71 extern struct passwd *getpwnam ();
  72 #endif
  73
  74 extern char *get_system_name ();
  75
  76 /* Make sure not to #include anything after these definitions.  Let's
  77    not step on anyone's prototypes.  */
  78 #ifdef emacs
  79 #define malloc xmalloc
  80 #define realloc xrealloc
  81 #define free xfree
  82 #endif
  83
  84 char *x_get_string_resource ();
  85 static int file_p ();
  86
  87 \f
  88 /* X file search path processing.  */
  89
  90
  91 /* The string which gets substituted for the %C escape in XFILESEARCHPATH
  92    and friends, or zero if none was specified.  */
  93 char *x_customization_string;
  94
  95
  96 /* Return the value of the emacs.customization (Emacs.Customization)
  97    resource, for later use in search path decoding.  If we find no
  98    such resource, return zero.  */
  99 char *
 100 x_get_customization_string (db, name, class)
 101      XrmDatabase db;
 102      char *name, *class;
 103 {
 104   char *full_name
 105     = (char *) alloca (strlen (name) + sizeof ("customization") + 3);
 106   char *full_class
 107     = (char *) alloca (strlen (class) + sizeof ("Customization") + 3);
 108   char *result;
 109
 110   sprintf (full_name,  "%s.%s", name,  "customization");
 111   sprintf (full_class, "%s.%s", class, "Customization");
 112
 113   result = x_get_string_resource (db, full_name, full_class);
 114
 115   if (result)
 116     {
 117       char *copy = (char *) malloc (strlen (result) + 1);
 118       strcpy (copy, result);
 119       return copy;
 120     }
 121   else
 122     return 0;
 123 }
 124
 125
 126 /* Expand all the Xt-style %-escapes in STRING, whose length is given
 127    by STRING_LEN.  Here are the escapes we're supposed to recognize:
 128
 129         %N      The value of the application's class name
 130         %T      The value of the type parameter ("app-defaults" in this
 131                 context)
 132         %S      The value of the suffix parameter ("" in this context)
 133         %L      The language string associated with the specified display
 134                 (We use the "LANG" environment variable here, if it's set.)
 135         %l      The language part of the display's language string
 136                 (We treat this just like %L.  If someone can tell us what
 137                  we're really supposed to do, dandy.)
 138         %t      The territory part of the display's language string
 139                 (This never gets used.)
 140         %c      The codeset part of the display's language string
 141                 (This never gets used either.)
 142         %C      The customization string retrieved from the resource
 143                 database associated with display.
 144                 (This is x_customization_string.)
 145
 146    Return the expanded file name if it exists and is readable, and
 147    refers to %L only when the LANG environment variable is set, or
 148    otherwise provided by X.
 149
 150    ESCAPED_SUFFIX and SUFFIX are postpended to STRING if they are
 151    non-zero.  %-escapes in ESCAPED_SUFFIX are expanded; STRING is left
 152    alone.
 153
 154    Return NULL otherwise.  */
 155
 156 static char *
 157 magic_file_p (string, string_len, class, escaped_suffix, suffix)
 158      char *string;
 159      int string_len;
 160      char *class, *escaped_suffix, *suffix;
 161 {
 162   char *lang = getenv ("LANG");
 163
 164   int path_size = 100;
 165   char *path = (char *) malloc (path_size);
 166   int path_len = 0;
 167
 168   char *p = string;
 169
 170   while (p < string + string_len)
 171     {
 172       /* The chunk we're about to stick on the end of result.  */
 173       char *next;
 174       int next_len;
 175
 176       if (*p == '%')
 177         {
 178           p++;
 179
 180           if (p >= string + string_len)
 181             next_len = 0;
 182           else
 183             switch (*p)
 184               {
 185               case '%':
 186                 next = "%";
 187                 next_len = 1;
 188                 break;
 189
 190               case 'C':
 191                 next = (x_customization_string
 192                         ? x_customization_string
 193                         : "");
 194                 next_len = strlen (next);
 195                 break;
 196
 197               case 'N':
 198                 next = class;
 199                 next_len = strlen (class);
 200                 break;
 201
 202               case 'T':
 203                 next = "app-defaults";
 204                 next_len = strlen (next);
 205                 break;
 206
 207               default:
 208               case 'S':
 209                 next_len = 0;
 210                 break;
 211
 212               case 'L':
 213               case 'l':
 214                 if (! lang)
 215                   {
 216                     free (path);
 217                     return NULL;
 218                   }
 219
 220                 next = lang;
 221                 next_len = strlen (next);
 222                 break;
 223
 224               case 't':
 225               case 'c':
 226                 free (path);
 227                 return NULL;
 228               }
 229         }
 230       else
 231         next = p, next_len = 1;
 232
 233       /* Do we have room for this component followed by a '\0' ?  */
 234       if (path_len + next_len + 1 > path_size)
 235         {
 236           path_size = (path_len + next_len + 1) * 2;
 237           path = (char *) realloc (path, path_size);
 238         }
 239
 240       bcopy (next, path + path_len, next_len);
 241       path_len += next_len;
 242
 243       p++;
 244
 245       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 246       if (p >= string + string_len && escaped_suffix)
 247         {
 248           string = escaped_suffix;
 249           string_len = strlen (string);
 250           p = string;
 251           escaped_suffix = NULL;
 252         }
 253     }
 254
 255   /* Perhaps we should add the SUFFIX now.  */
 256   if (suffix)
 257     {
 258       int suffix_len = strlen (suffix);
 259
 260       if (path_len + suffix_len + 1 > path_size)
 261         {
 262           path_size = (path_len + suffix_len + 1);
 263           path = (char *) realloc (path, path_size);
 264         }
 265
 266       bcopy (suffix, path + path_len, suffix_len);
 267       path_len += suffix_len;
 268     }
 269
 270   path[path_len] = '\0';
 271
 272   if (! file_p (path))
 273     {
 274       free (path);
 275       return NULL;
 276     }
 277
 278   return path;
 279 }
 280
 281
 282 static char *
 283 gethomedir ()
 284 {
 285   struct passwd *pw;
 286   char *ptr;
 287   char *copy;
 288
 289   if ((ptr = getenv ("HOME")) == NULL)
 290     {
 291       if ((ptr = getenv ("LOGNAME")) != NULL
 292           || (ptr = getenv ("USER")) != NULL)
 293         pw = getpwnam (ptr);
 294       else
 295         pw = getpwuid (getuid ());
 296
 297       if (pw)
 298         ptr = pw->pw_dir;
 299     }
 300
 301   if (ptr == NULL)
 302     return "/";
 303
 304   copy = (char *) malloc (strlen (ptr) + 2);
 305   strcpy (copy, ptr);
 306   strcat (copy, "/");
 307
 308   return copy;
 309 }
 310
 311
 312 static int
 313 file_p (path)
 314      char *path;
 315 {
 316   struct stat status;
 317
 318   return (access (path, 4) == 0                 /* exists and is readable */
 319           && stat (path, &status) == 0          /* get the status */
 320           && (S_ISDIR (status.st_mode)) == 0);  /* not a directory */
 321 }
 322
 323
 324 /* Find the first element of SEARCH_PATH which exists and is readable,
 325    after expanding the %-escapes.  Return 0 if we didn't find any, and
 326    the path name of the one we found otherwise.  */
 327
 328 static char *
 329 search_magic_path (search_path, class, escaped_suffix, suffix)
 330      char *search_path, *class, *escaped_suffix, *suffix;
 331 {
 332   register char *s, *p;
 333
 334   for (s = search_path; *s; s = p)
 335     {
 336       for (p = s; *p && *p != ':'; p++)
 337         ;
 338
 339       if (p > s)
 340         {
 341           char *path = magic_file_p (s, p - s, class, escaped_suffix, suffix);
 342           if (path)
 343             return path;
 344         }
 345       else if (*p == ':')
 346         {
 347           char *path;
 348
 349           s = "%N%S";
 350           path = magic_file_p (s, strlen (s), class, escaped_suffix, suffix);
 351           if (path)
 352             return path;
 353         }
 354
 355       if (*p == ':')
 356         p++;
 357     }
 358
 359   return 0;
 360 }
 361 \f
 362 /* Producing databases for individual sources.  */
 363
 364 #define X_DEFAULT_SEARCH_PATH "/usr/lib/X11/%L/%T/%N%C%S:/usr/lib/X11/%l/%T/%N%C%S:/usr/lib/X11/%T/%N%C%S:/usr/lib/X11/%L/%T/%N%S:/usr/lib/X11/%l/%T/%N%S:/usr/lib/X11/%T/%N%S"
 365
 366 static XrmDatabase
 367 get_system_app (class)
 368      char *class;
 369 {
 370   XrmDatabase db = NULL;
 371   char *path;
 372
 373   path = getenv ("XFILESEARCHPATH");
 374   if (! path) path = X_DEFAULT_SEARCH_PATH;
 375
 376   path = search_magic_path (path, class, 0, 0);
 377   if (path)
 378     {
 379       db = XrmGetFileDatabase (path);
 380       free (path);
 381     }
 382
 383   return db;
 384 }
 385
 386
 387 static XrmDatabase
 388 get_fallback (display)
 389      Display *display;
 390 {
 391   XrmDatabase db;
 392
 393   return NULL;
 394 }
 395
 396
 397 static XrmDatabase
 398 get_user_app (class)
 399      char *class;
 400 {
 401   char *path;
 402   char *file = 0;
 403
 404   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 405      names, not directories.  */
 406   if (((path = getenv ("XUSERFILESEARCHPATH"))
 407        && (file = search_magic_path (path, class, 0, 0)))
 408
 409       /* Check for APPLRESDIR; it is a path of directories.  In each,
 410          we have to search for LANG/CLASS and then CLASS.  */
 411       || ((path = getenv ("XAPPLRESDIR"))
 412           && ((file = search_magic_path (path, class, "/%L/%N", 0))
 413               || (file = search_magic_path (path, class, "/%N", 0))))
 414
 415       /* Check in the home directory.  This is a bit of a hack; let's
 416          hope one's home directory doesn't contain any %-escapes.  */
 417       || (path = gethomedir (),
 418           ((file = search_magic_path (path, class, "%L/%N", 0))
 419            || (file = search_magic_path (path, class, "%N", 0)))))
 420     {
 421       XrmDatabase db = XrmGetFileDatabase (file);
 422       free (file);
 423       return db;
 424     }
 425   else
 426     return NULL;
 427 }
 428
 429
 430 static XrmDatabase
 431 get_user_db (display)
 432      Display *display;
 433 {
 434   XrmDatabase db;
 435   char *xdefs;
 436
 437 #ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
 438   xdefs = XResourceManagerString (display);
 439 #else
 440   xdefs = display->xdefaults;
 441 #endif
 442
 443   if (xdefs != NULL)
 444     db = XrmGetStringDatabase (xdefs);
 445   else
 446     {
 447       char *home;
 448       char *xdefault;
 449
 450       home = gethomedir ();
 451       xdefault = (char *) malloc (strlen (home) + sizeof (".Xdefaults"));
 452       strcpy (xdefault, home);
 453       strcat (xdefault, ".Xdefaults");
 454       db = XrmGetFileDatabase (xdefault);
 455       free (home);
 456       free (xdefault);
 457     }
 458
 459 #ifdef HAVE_XSCREENRESOURCESTRING
 460   /* Get the screen-specific resources too.  */
 461   xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
 462   if (xdefs != NULL)
 463     {
 464       XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
 465       XFree (xdefs);
 466     }
 467 #endif
 468
 469   return db;
 470 }
 471
 472 static XrmDatabase
 473 get_environ_db ()
 474 {
 475   XrmDatabase db;
 476   char *p;
 477   char *path = 0, *home = 0, *host;
 478
 479   if ((p = getenv ("XENVIRONMENT")) == NULL)
 480     {
 481       home = gethomedir ();
 482       host = get_system_name ();
 483       path = (char *) malloc (strlen (home)
 484                               + sizeof (".Xdefaults-")
 485                               + strlen (host));
 486       sprintf (path, "%s%s%s", home, ".Xdefaults-", host);
 487       p = path;
 488     }
 489
 490   db = XrmGetFileDatabase (p);
 491
 492   if (path) free (path);
 493   if (home) free (home);
 494
 495   return db;
 496 }
 497 \f
 498 /* External interface.  */
 499
 500 /* Types of values that we can find in a database */
 501
 502 #define XrmStringType "String"  /* String representation */
 503 XrmRepresentation x_rm_string;  /* Quark representation */
 504
 505 /* Load X resources based on the display and a possible -xrm option. */
 506
 507 XrmDatabase
 508 x_load_resources (display, xrm_string, myname, myclass)
 509      Display *display;
 510      char *xrm_string, *myname, *myclass;
 511 {
 512   char *xdefs;
 513   XrmDatabase user_database;
 514   XrmDatabase rdb;
 515   XrmDatabase db;
 516
 517   x_rm_string = XrmStringToQuark (XrmStringType);
 518 #ifndef USE_X_TOOLKIT
 519   /* pmr@osf.org says this shouldn't be done if USE_X_TOOLKIT.
 520      I suspect it's because the toolkit version does this elsewhere.  */
 521   XrmInitialize ();
 522 #endif
 523   rdb = XrmGetStringDatabase ("");
 524
 525   user_database = get_user_db (display);
 526
 527   /* Figure out what the "customization string" is, so we can use it
 528      to decode paths.  */
 529   if (x_customization_string)
 530     free (x_customization_string);
 531   x_customization_string
 532     = x_get_customization_string (user_database, myname, myclass);
 533
 534   /* Get application system defaults */
 535   db = get_system_app (myclass);
 536   if (db != NULL)
 537     XrmMergeDatabases (db, &rdb);
 538
 539   /* Get Fallback resources */
 540   db = get_fallback (display);
 541   if (db != NULL)
 542     XrmMergeDatabases (db, &rdb);
 543
 544   /* Get application user defaults */
 545   db = get_user_app (myclass);
 546   if (db != NULL)
 547     XrmMergeDatabases (db, &rdb);
 548
 549   /* get User defaults */
 550   if (user_database != NULL)
 551     XrmMergeDatabases (user_database, &rdb);
 552
 553   /* Get Environment defaults. */
 554   db = get_environ_db ();
 555   if (db != NULL)
 556     XrmMergeDatabases (db, &rdb);
 557
 558   /* Last, merge in any specification from the command line. */
 559   if (xrm_string != NULL)
 560     {
 561       db = XrmGetStringDatabase (xrm_string);
 562       if (db != NULL)
 563         XrmMergeDatabases (db, &rdb);
 564     }
 565
 566   return rdb;
 567 }
 568
 569
 570 /* Retrieve the value of the resource specified by NAME with class CLASS
 571    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 572
 573 int
 574 x_get_resource (rdb, name, class, expected_type, ret_value)
 575      XrmDatabase rdb;
 576      char *name, *class;
 577      XrmRepresentation expected_type;
 578      XrmValue *ret_value;
 579 {
 580   XrmValue value;
 581   XrmName namelist[100];
 582   XrmClass classlist[100];
 583   XrmRepresentation type;
 584
 585   XrmStringToNameList(name, namelist);
 586   XrmStringToClassList(class, classlist);
 587
 588   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 589       && (type == expected_type))
 590     {
 591       if (type == x_rm_string)
 592         ret_value->addr = (char *) value.addr;
 593       else
 594         bcopy (value.addr, ret_value->addr, ret_value->size);
 595
 596       return value.size;
 597     }
 598
 599   return 0;
 600 }
 601
 602 /* Retrieve the string resource specified by NAME with CLASS from
 603    database RDB. */
 604
 605 char *
 606 x_get_string_resource (rdb, name, class)
 607      XrmDatabase rdb;
 608      char *name, *class;
 609 {
 610   XrmValue value;
 611
 612   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 613     return (char *) value.addr;
 614
 615   return (char *) 0;
 616 }
 617 \f
 618 /* Stand-alone test facilities.  */
 619
 620 #ifdef TESTRM
 621
 622 typedef char **List;
 623 #define arg_listify(len, list) (list)
 624 #define car(list) (*(list))
 625 #define cdr(list) (list + 1)
 626 #define NIL(list) (! *(list))
 627 #define free_arglist(list)
 628
 629 static List
 630 member (elt, list)
 631      char *elt;
 632      List list;
 633 {
 634   List p;
 635
 636   for (p = list; ! NIL (p); p = cdr (p))
 637     if (! strcmp (elt, car (p)))
 638       return p;
 639
 640   return p;
 641 }
 642
 643 static void
 644 fatal (msg, prog, x1, x2, x3, x4, x5)
 645     char *msg, *prog;
 646     int x1, x2, x3, x4, x5;
 647 {
 648     extern int errno;
 649
 650     if (errno)
 651       perror (prog);
 652
 653     (void) fprintf (stderr, msg, prog, x1, x2, x3, x4, x5);
 654     exit (1);
 655 }
 656
 657 main (argc, argv)
 658     int argc;
 659     char **argv;
 660 {
 661   Display *display;
 662   char *displayname, *resource_string, *class, *name;
 663   XrmDatabase xdb;
 664   List arg_list, lp;
 665
 666   arg_list = arg_listify (argc, argv);
 667
 668   lp = member ("-d", arg_list);
 669   if (!NIL (lp))
 670     displayname = car (cdr (lp));
 671   else
 672     displayname = "localhost:0.0";
 673
 674   lp = member ("-xrm", arg_list);
 675   if (! NIL (lp))
 676     resource_string = car (cdr (lp));
 677   else
 678     resource_string = (char *) 0;
 679
 680   lp = member ("-c", arg_list);
 681   if (! NIL (lp))
 682     class = car (cdr (lp));
 683   else
 684     class = "Emacs";
 685
 686   lp = member ("-n", arg_list);
 687   if (! NIL (lp))
 688     name = car (cdr (lp));
 689   else
 690     name = "emacs";
 691
 692   free_arglist (arg_list);
 693
 694   if (!(display = XOpenDisplay (displayname)))
 695     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 696
 697   xdb = x_load_resources (display, resource_string, name, class);
 698
 699   /* In a real program, you'd want to also do this: */
 700   display->db = xdb;
 701
 702   while (1)
 703     {
 704       char query_name[90];
 705       char query_class[90];
 706
 707       printf ("Name: ");
 708       gets (query_name);
 709
 710       if (strlen (query_name))
 711         {
 712           char *value;
 713
 714           printf ("Class: ");
 715           gets (query_class);
 716
 717           value = x_get_string_resource (xdb, query_name, query_class);
 718
 719           if (value != NULL)
 720             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 721           else
 722             printf ("\tNo Value.\n\n");
 723         }
 724       else
 725         break;
 726     }
 727   printf ("\tExit.\n\n");
 728
 729   XCloseDisplay (display);
 730 }
 731 #endif /* TESTRM */