code.delx.au - gnu-emacs/blob - src/xrdb.c

   1 /* Deal with the X Resource Manager.
   2    Copyright (C) 1990, 1993 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 #define SYSV
  30 #include <unistd.h>
  31 #endif /* USG5 */
  32
  33 #endif /* 1 */
  34
  35 /* This should be included before the X include files; otherwise, we get
  36    warnings about redefining NULL under BSD 4.3.  */
  37 #include <sys/param.h>
  38
  39 #include <X11/Xlib.h>
  40 #include <X11/Xatom.h>
  41 #if 0
  42 #include <X11/Xos.h>
  43 #endif
  44 #include <X11/X.h>
  45 #include <X11/Xutil.h>
  46 #include <X11/Xresource.h>
  47 #ifdef VMS
  48 #include "vms-pwd.h"
  49 #else
  50 #include <pwd.h>
  51 #endif
  52 #include <sys/stat.h>
  53
  54 #ifndef MAXPATHLEN
  55 #define MAXPATHLEN      256
  56 #endif
  57
  58 extern char *getenv ();
  59
  60 /* This does cause trouble on AIX.  I'm going to take the comment at
  61    face value.  */
  62 #if 0
  63 extern short getuid ();         /* If this causes portability problems,
  64                                    I think we should just delete it; it'll
  65                                    default to `int' anyway.  */
  66 #endif
  67
  68 #if defined (__bsdi__) || defined (DECLARE_GETPWUID_WITH_UID_T)
  69 extern struct passwd *getpwuid (uid_t);
  70 extern struct passwd *getpwnam (const char *);
  71 #else
  72 extern struct passwd *getpwuid ();
  73 extern struct passwd *getpwnam ();
  74 #endif
  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     return strcpy ((char *) malloc (strlen (result) + 1), result);
 117   else
 118     return 0;
 119 }
 120
 121
 122 /* Expand all the Xt-style %-escapes in STRING, whose length is given
 123    by STRING_LEN.  Here are the escapes we're supposed to recognize:
 124
 125         %N      The value of the application's class name
 126         %T      The value of the type parameter ("app-defaults" in this
 127                 context)
 128         %S      The value of the suffix parameter ("" in this context)
 129         %L      The language string associated with the specified display
 130                 (We use the "LANG" environment variable here, if it's set.)
 131         %l      The language part of the display's language string
 132                 (We treat this just like %L.  If someone can tell us what
 133                  we're really supposed to do, dandy.)
 134         %t      The territory part of the display's language string
 135                 (This never gets used.)
 136         %c      The codeset part of the display's language string
 137                 (This never gets used either.)
 138         %C      The customization string retrieved from the resource
 139                 database associated with display.
 140                 (This is x_customization_string.)
 141
 142    Return the expanded file name if it exists and is readable, and
 143    refers to %L only when the LANG environment variable is set, or
 144    otherwise provided by X.
 145
 146    ESCAPED_SUFFIX and SUFFIX are postpended to STRING if they are
 147    non-zero.  %-escapes in ESCAPED_SUFFIX are expanded; STRING is left
 148    alone.
 149
 150    Return NULL otherwise.  */
 151
 152 static char *
 153 magic_file_p (string, string_len, class, escaped_suffix, suffix)
 154      char *string;
 155      int string_len;
 156      char *class, *escaped_suffix, *suffix;
 157 {
 158   char *lang = getenv ("LANG");
 159
 160   int path_size = 100;
 161   char *path = (char *) malloc (path_size);
 162   int path_len = 0;
 163
 164   char *p = string;
 165
 166   while (p < string + string_len)
 167     {
 168       /* The chunk we're about to stick on the end of result.  */
 169       char *next;
 170       int next_len;
 171
 172       if (*p == '%')
 173         {
 174           p++;
 175
 176           if (p >= string + string_len)
 177             next_len = 0;
 178           else
 179             switch (*p)
 180               {
 181               case '%':
 182                 next = "%";
 183                 next_len = 1;
 184                 break;
 185
 186               case 'C':
 187                 next = (x_customization_string
 188                         ? x_customization_string
 189                         : "");
 190                 next_len = strlen (next);
 191                 break;
 192
 193               case 'N':
 194                 next = class;
 195                 next_len = strlen (class);
 196                 break;
 197
 198               case 'T':
 199                 next = "app-defaults";
 200                 next_len = strlen (next);
 201                 break;
 202
 203               default:
 204               case 'S':
 205                 next_len = 0;
 206                 break;
 207
 208               case 'L':
 209               case 'l':
 210                 if (! lang)
 211                   {
 212                     free (path);
 213                     return NULL;
 214                   }
 215
 216                 next = lang;
 217                 next_len = strlen (next);
 218                 break;
 219
 220               case 't':
 221               case 'c':
 222                 free (path);
 223                 return NULL;
 224               }
 225         }
 226       else
 227         next = p, next_len = 1;
 228
 229       /* Do we have room for this component followed by a '\0' ?  */
 230       if (path_len + next_len + 1 > path_size)
 231         {
 232           path_size = (path_len + next_len + 1) * 2;
 233           path = (char *) realloc (path, path_size);
 234         }
 235
 236       bcopy (next, path + path_len, next_len);
 237       path_len += next_len;
 238
 239       p++;
 240
 241       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 242       if (p >= string + string_len && escaped_suffix)
 243         {
 244           string = escaped_suffix;
 245           string_len = strlen (string);
 246           p = string;
 247           escaped_suffix = NULL;
 248         }
 249     }
 250
 251   /* Perhaps we should add the SUFFIX now.  */
 252   if (suffix)
 253     {
 254       int suffix_len = strlen (suffix);
 255
 256       if (path_len + suffix_len + 1 > path_size)
 257         {
 258           path_size = (path_len + suffix_len + 1);
 259           path = (char *) realloc (path, path_size);
 260         }
 261
 262       bcopy (suffix, path + path_len, suffix_len);
 263       path_len += suffix_len;
 264     }
 265
 266   path[path_len] = '\0';
 267
 268   if (! file_p (path))
 269     {
 270       free (path);
 271       return NULL;
 272     }
 273
 274   return path;
 275 }
 276
 277
 278 static char *
 279 gethomedir ()
 280 {
 281   int uid;
 282   struct passwd *pw;
 283   char *ptr;
 284   char *copy;
 285
 286   if ((ptr = getenv ("HOME")) == NULL)
 287     {
 288       if ((ptr = getenv ("USER")) != NULL)
 289         pw = getpwnam (ptr);
 290       else
 291         {
 292           uid = getuid ();
 293           pw = getpwuid (uid);
 294         }
 295
 296       if (pw)
 297         ptr = pw->pw_dir;
 298     }
 299
 300   if (ptr == NULL)
 301     return "/";
 302
 303   copy = (char *) malloc (strlen (ptr) + 2);
 304   strcpy (copy, ptr);
 305   strcat (copy, "/");
 306
 307   return copy;
 308 }
 309
 310
 311 static int
 312 file_p (path)
 313      char *path;
 314 {
 315   struct stat status;
 316
 317   return (access (path, 4) == 0                 /* exists and is readable */
 318           && stat (path, &status) == 0          /* get the status */
 319           && (status.st_mode & S_IFDIR) == 0);  /* not a directory */
 320 }
 321
 322
 323 /* Find the first element of SEARCH_PATH which exists and is readable,
 324    after expanding the %-escapes.  Return 0 if we didn't find any, and
 325    the path name of the one we found otherwise.  */
 326
 327 static char *
 328 search_magic_path (search_path, class, escaped_suffix, suffix)
 329      char *search_path, *class, *escaped_suffix, *suffix;
 330 {
 331   register char *s, *p;
 332
 333   for (s = search_path; *s; s = p)
 334     {
 335       for (p = s; *p && *p != ':'; p++)
 336         ;
 337
 338       if (*p == ':' && *(p + 1) == ':')
 339         {
 340           char *path;
 341
 342           s = "%N%S";
 343           path = magic_file_p (s, strlen (s), class, escaped_suffix, suffix);
 344           if (path)
 345             return path;
 346
 347           s = p + 1;
 348           continue;
 349         }
 350
 351       if (p > s)
 352         {
 353           char *path = magic_file_p (s, p - s, class, escaped_suffix, suffix);
 354           if (path)
 355             return path;
 356         }
 357
 358       if (*p == ':')
 359         p++;
 360     }
 361
 362   return 0;
 363 }
 364 \f
 365 /* Producing databases for individual sources.  */
 366
 367 #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"
 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 = X_DEFAULT_SEARCH_PATH;
 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
 407   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 408      names, not directories.  */
 409   if (((path = getenv ("XUSERFILESEARCHPATH"))
 410        && (file = search_magic_path (path, class, 0, 0)))
 411
 412       /* Check for APPLRESDIR; it is a path of directories.  In each,
 413          we have to search for LANG/CLASS and then CLASS.  */
 414       || ((path = getenv ("XAPPLRESDIR"))
 415           && ((file = search_magic_path (path, class, "/%L/%N", 0))
 416               || (file = search_magic_path (path, class, "/%N", 0))))
 417
 418       /* Check in the home directory.  This is a bit of a hack; let's
 419          hope one's home directory doesn't contain any %-escapes.  */
 420       || (path = gethomedir (),
 421           ((file = search_magic_path (path, class, "%L/%N", 0))
 422            || (file = search_magic_path (path, class, "%N", 0)))))
 423     {
 424       XrmDatabase db = XrmGetFileDatabase (file);
 425       free (file);
 426       return db;
 427     }
 428   else
 429     return NULL;
 430 }
 431
 432
 433 static XrmDatabase
 434 get_user_db (display)
 435      Display *display;
 436 {
 437   XrmDatabase db;
 438   char *xdefs;
 439
 440 #ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
 441   xdefs = XResourceManagerString (display);
 442 #else
 443   xdefs = display->xdefaults;
 444 #endif
 445
 446   if (xdefs != NULL)
 447     db = XrmGetStringDatabase (xdefs);
 448   else
 449     {
 450       char *home;
 451       char *xdefault;
 452
 453       home = gethomedir ();
 454       xdefault = (char *) malloc (strlen (home) + sizeof (".Xdefaults"));
 455       strcpy (xdefault, home);
 456       strcat (xdefault, ".Xdefaults");
 457       db = XrmGetFileDatabase (xdefault);
 458       free (home);
 459       free (xdefault);
 460     }
 461
 462 #ifdef XlibSpecificationRelease
 463 #if XlibSpecificationRelease >= 5
 464   /* Get the screen-specific resources too.  */
 465   xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
 466   if (xdefs != NULL)
 467     {
 468       XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
 469       XFree (xdefs);
 470     }
 471 #endif
 472 #endif
 473
 474   return db;
 475 }
 476
 477 static XrmDatabase
 478 get_environ_db ()
 479 {
 480   XrmDatabase db;
 481   char *p;
 482   char *path = 0, *home = 0, *host = 0;
 483
 484   if ((p = getenv ("XENVIRONMENT")) == NULL)
 485     {
 486       home = gethomedir ();
 487
 488       {
 489         int host_size = 100;
 490         host = (char *) malloc (host_size);
 491
 492         for (;;)
 493           {
 494             host[host_size - 1] = '\0';
 495             gethostname (host, host_size - 1);
 496             if (strlen (host) < host_size - 1)
 497               break;
 498             host = (char *) realloc (host, host_size *= 2);
 499           }
 500       }
 501
 502       path = (char *) malloc (strlen (home)
 503                               + sizeof (".Xdefaults-")
 504                               + strlen (host));
 505       sprintf (path, "%s%s%s", home, ".Xdefaults-", host);
 506       p = path;
 507     }
 508
 509   db = XrmGetFileDatabase (p);
 510
 511   if (path) free (path);
 512   if (home) free (home);
 513   if (host) free (host);
 514
 515   return db;
 516 }
 517 \f
 518 /* External interface.  */
 519
 520 /* Types of values that we can find in a database */
 521
 522 #define XrmStringType "String"  /* String representation */
 523 XrmRepresentation x_rm_string;  /* Quark representation */
 524
 525 /* Load X resources based on the display and a possible -xrm option. */
 526
 527 XrmDatabase
 528 x_load_resources (display, xrm_string, myname, myclass)
 529      Display *display;
 530      char *xrm_string, *myname, *myclass;
 531 {
 532   char *xdefs;
 533   XrmDatabase user_database;
 534   XrmDatabase rdb;
 535   XrmDatabase db;
 536
 537   x_rm_string = XrmStringToQuark (XrmStringType);
 538   XrmInitialize ();
 539   rdb = XrmGetStringDatabase ("");
 540
 541   user_database = get_user_db (display);
 542
 543   /* Figure out what the "customization string" is, so we can use it
 544      to decode paths.  */
 545   if (x_customization_string)
 546     free (x_customization_string);
 547   x_customization_string
 548     = x_get_customization_string (user_database, myname, myclass);
 549
 550   /* Get application system defaults */
 551   db = get_system_app (myclass);
 552   if (db != NULL)
 553     XrmMergeDatabases (db, &rdb);
 554
 555   /* Get Fallback resources */
 556   db = get_fallback (display);
 557   if (db != NULL)
 558     XrmMergeDatabases (db, &rdb);
 559
 560   /* Get application user defaults */
 561   db = get_user_app (myclass);
 562   if (db != NULL)
 563     XrmMergeDatabases (db, &rdb);
 564
 565   /* get User defaults */
 566   if (user_database != NULL)
 567     XrmMergeDatabases (user_database, &rdb);
 568
 569   /* Get Environment defaults. */
 570   db = get_environ_db ();
 571   if (db != NULL)
 572     XrmMergeDatabases (db, &rdb);
 573
 574   /* Last, merge in any specification from the command line. */
 575   if (xrm_string != NULL)
 576     {
 577       db = XrmGetStringDatabase (xrm_string);
 578       if (db != NULL)
 579         XrmMergeDatabases (db, &rdb);
 580     }
 581
 582   return rdb;
 583 }
 584
 585
 586 /* Retrieve the value of the resource specified by NAME with class CLASS
 587    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 588
 589 int
 590 x_get_resource (rdb, name, class, expected_type, ret_value)
 591      XrmDatabase rdb;
 592      char *name, *class;
 593      XrmRepresentation expected_type;
 594      XrmValue *ret_value;
 595 {
 596   XrmValue value;
 597   XrmName namelist[100];
 598   XrmClass classlist[100];
 599   XrmRepresentation type;
 600
 601   XrmStringToNameList(name, namelist);
 602   XrmStringToClassList(class, classlist);
 603
 604   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 605       && (type == expected_type))
 606     {
 607       if (type == x_rm_string)
 608         ret_value->addr = (char *) value.addr;
 609       else
 610         bcopy (value.addr, ret_value->addr, ret_value->size);
 611
 612       return value.size;
 613     }
 614
 615   return 0;
 616 }
 617
 618 /* Retrieve the string resource specified by NAME with CLASS from
 619    database RDB. */
 620
 621 char *
 622 x_get_string_resource (rdb, name, class)
 623      XrmDatabase rdb;
 624      char *name, *class;
 625 {
 626   XrmValue value;
 627
 628   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 629     return (char *) value.addr;
 630
 631   return (char *) 0;
 632 }
 633 \f
 634 /* Stand-alone test facilities.  */
 635
 636 #ifdef TESTRM
 637
 638 typedef char **List;
 639 #define arg_listify(len, list) (list)
 640 #define car(list) (*(list))
 641 #define cdr(list) (list + 1)
 642 #define NIL(list) (! *(list))
 643 #define free_arglist(list)
 644
 645 static List
 646 member (elt, list)
 647      char *elt;
 648      List list;
 649 {
 650   List p;
 651
 652   for (p = list; ! NIL (p); p = cdr (p))
 653     if (! strcmp (elt, car (p)))
 654       return p;
 655
 656   return p;
 657 }
 658
 659 static void
 660 fatal (msg, prog, x1, x2, x3, x4, x5)
 661     char *msg, *prog;
 662     int x1, x2, x3, x4, x5;
 663 {
 664     extern int errno;
 665
 666     if (errno)
 667       perror (prog);
 668
 669     (void) fprintf (stderr, msg, prog, x1, x2, x3, x4, x5);
 670     exit (1);
 671 }
 672
 673 main (argc, argv)
 674     int argc;
 675     char **argv;
 676 {
 677   Display *display;
 678   char *displayname, *resource_string, *class, *name;
 679   XrmDatabase xdb;
 680   List arg_list, lp;
 681
 682   arg_list = arg_listify (argc, argv);
 683
 684   lp = member ("-d", arg_list);
 685   if (!NIL (lp))
 686     displayname = car (cdr (lp));
 687   else
 688     displayname = "localhost:0.0";
 689
 690   lp = member ("-xrm", arg_list);
 691   if (! NIL (lp))
 692     resource_string = car (cdr (lp));
 693   else
 694     resource_string = (char *) 0;
 695
 696   lp = member ("-c", arg_list);
 697   if (! NIL (lp))
 698     class = car (cdr (lp));
 699   else
 700     class = "Emacs";
 701
 702   lp = member ("-n", arg_list);
 703   if (! NIL (lp))
 704     name = car (cdr (lp));
 705   else
 706     name = "emacs";
 707
 708   free_arglist (arg_list);
 709
 710   if (!(display = XOpenDisplay (displayname)))
 711     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 712
 713   xdb = x_load_resources (display, resource_string, name, class);
 714
 715   /* In a real program, you'd want to also do this: */
 716   display->db = xdb;
 717
 718   while (1)
 719     {
 720       char query_name[90];
 721       char query_class[90];
 722
 723       printf ("Name: ");
 724       gets (query_name);
 725
 726       if (strlen (query_name))
 727         {
 728           char *value;
 729
 730           printf ("Class: ");
 731           gets (query_class);
 732
 733           value = x_get_string_resource (xdb, query_name, query_class);
 734
 735           if (value != NULL)
 736             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 737           else
 738             printf ("\tNo Value.\n\n");
 739         }
 740       else
 741         break;
 742     }
 743   printf ("\tExit.\n\n");
 744
 745   XCloseDisplay (display);
 746 }
 747 #endif /* TESTRM */