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