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 <stdio.h>
  28
  29 #if 1 /* I'd really appreciate it if this code could go away...  -JimB */
  30 /* this avoids lossage in the `dual-universe' headers on AT&T SysV X11 */
  31 #ifdef USG5
  32 #ifndef SYSV
  33 #define SYSV
  34 #endif
  35 #include <unistd.h>
  36 #endif /* USG5 */
  37
  38 #endif /* 1 */
  39
  40 #include <X11/Xlib.h>
  41 #include <X11/Xatom.h>
  42 #if 0
  43 #include <X11/Xos.h>
  44 #endif
  45 #include <X11/X.h>
  46 #include <X11/Xutil.h>
  47 #include <X11/Xresource.h>
  48 #ifdef VMS
  49 #include "vms-pwd.h"
  50 #else
  51 #include <pwd.h>
  52 #endif
  53 #include <sys/stat.h>
  54
  55 #if !defined(S_ISDIR) && defined(S_IFDIR)
  56 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  57 #endif
  58
  59 extern char *getenv ();
  60
  61 /* This does cause trouble on AIX.  I'm going to take the comment at
  62    face value.  */
  63 #if 0
  64 extern short getuid ();         /* If this causes portability problems,
  65                                    I think we should just delete it; it'll
  66                                    default to `int' anyway.  */
  67 #endif
  68
  69 #ifdef DECLARE_GETPWUID_WITH_UID_T
  70 extern struct passwd *getpwuid (uid_t);
  71 extern struct passwd *getpwnam (const char *);
  72 #else
  73 extern struct passwd *getpwuid ();
  74 extern struct passwd *getpwnam ();
  75 #endif
  76
  77 extern char *get_system_name ();
  78
  79 /* Make sure not to #include anything after these definitions.  Let's
  80    not step on anyone's prototypes.  */
  81 #ifdef emacs
  82 #define malloc xmalloc
  83 #define realloc xrealloc
  84 #define free xfree
  85 #endif
  86
  87 char *x_get_string_resource ();
  88 static int file_p ();
  89
  90 \f
  91 /* X file search path processing.  */
  92
  93
  94 /* The string which gets substituted for the %C escape in XFILESEARCHPATH
  95    and friends, or zero if none was specified.  */
  96 char *x_customization_string;
  97
  98
  99 /* Return the value of the emacs.customization (Emacs.Customization)
 100    resource, for later use in search path decoding.  If we find no
 101    such resource, return zero.  */
 102 char *
 103 x_get_customization_string (db, name, class)
 104      XrmDatabase db;
 105      char *name, *class;
 106 {
 107   char *full_name
 108     = (char *) alloca (strlen (name) + sizeof ("customization") + 3);
 109   char *full_class
 110     = (char *) alloca (strlen (class) + sizeof ("Customization") + 3);
 111   char *result;
 112
 113   sprintf (full_name,  "%s.%s", name,  "customization");
 114   sprintf (full_class, "%s.%s", class, "Customization");
 115
 116   result = x_get_string_resource (db, full_name, full_class);
 117
 118   if (result)
 119     {
 120       char *copy = (char *) malloc (strlen (result) + 1);
 121       strcpy (copy, result);
 122       return copy;
 123     }
 124   else
 125     return 0;
 126 }
 127
 128
 129 /* Expand all the Xt-style %-escapes in STRING, whose length is given
 130    by STRING_LEN.  Here are the escapes we're supposed to recognize:
 131
 132         %N      The value of the application's class name
 133         %T      The value of the type parameter ("app-defaults" in this
 134                 context)
 135         %S      The value of the suffix parameter ("" in this context)
 136         %L      The language string associated with the specified display
 137                 (We use the "LANG" environment variable here, if it's set.)
 138         %l      The language part of the display's language string
 139                 (We treat this just like %L.  If someone can tell us what
 140                  we're really supposed to do, dandy.)
 141         %t      The territory part of the display's language string
 142                 (This never gets used.)
 143         %c      The codeset part of the display's language string
 144                 (This never gets used either.)
 145         %C      The customization string retrieved from the resource
 146                 database associated with display.
 147                 (This is x_customization_string.)
 148
 149    Return the expanded file name if it exists and is readable, and
 150    refers to %L only when the LANG environment variable is set, or
 151    otherwise provided by X.
 152
 153    ESCAPED_SUFFIX and SUFFIX are postpended to STRING if they are
 154    non-zero.  %-escapes in ESCAPED_SUFFIX are expanded; STRING is left
 155    alone.
 156
 157    Return NULL otherwise.  */
 158
 159 static char *
 160 magic_file_p (string, string_len, class, escaped_suffix, suffix)
 161      char *string;
 162      int string_len;
 163      char *class, *escaped_suffix, *suffix;
 164 {
 165   char *lang = getenv ("LANG");
 166
 167   int path_size = 100;
 168   char *path = (char *) malloc (path_size);
 169   int path_len = 0;
 170
 171   char *p = string;
 172
 173   while (p < string + string_len)
 174     {
 175       /* The chunk we're about to stick on the end of result.  */
 176       char *next;
 177       int next_len;
 178
 179       if (*p == '%')
 180         {
 181           p++;
 182
 183           if (p >= string + string_len)
 184             next_len = 0;
 185           else
 186             switch (*p)
 187               {
 188               case '%':
 189                 next = "%";
 190                 next_len = 1;
 191                 break;
 192
 193               case 'C':
 194                 next = (x_customization_string
 195                         ? x_customization_string
 196                         : "");
 197                 next_len = strlen (next);
 198                 break;
 199
 200               case 'N':
 201                 next = class;
 202                 next_len = strlen (class);
 203                 break;
 204
 205               case 'T':
 206                 next = "app-defaults";
 207                 next_len = strlen (next);
 208                 break;
 209
 210               default:
 211               case 'S':
 212                 next_len = 0;
 213                 break;
 214
 215               case 'L':
 216               case 'l':
 217                 if (! lang)
 218                   {
 219                     free (path);
 220                     return NULL;
 221                   }
 222
 223                 next = lang;
 224                 next_len = strlen (next);
 225                 break;
 226
 227               case 't':
 228               case 'c':
 229                 free (path);
 230                 return NULL;
 231               }
 232         }
 233       else
 234         next = p, next_len = 1;
 235
 236       /* Do we have room for this component followed by a '\0' ?  */
 237       if (path_len + next_len + 1 > path_size)
 238         {
 239           path_size = (path_len + next_len + 1) * 2;
 240           path = (char *) realloc (path, path_size);
 241         }
 242
 243       bcopy (next, path + path_len, next_len);
 244       path_len += next_len;
 245
 246       p++;
 247
 248       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 249       if (p >= string + string_len && escaped_suffix)
 250         {
 251           string = escaped_suffix;
 252           string_len = strlen (string);
 253           p = string;
 254           escaped_suffix = NULL;
 255         }
 256     }
 257
 258   /* Perhaps we should add the SUFFIX now.  */
 259   if (suffix)
 260     {
 261       int suffix_len = strlen (suffix);
 262
 263       if (path_len + suffix_len + 1 > path_size)
 264         {
 265           path_size = (path_len + suffix_len + 1);
 266           path = (char *) realloc (path, path_size);
 267         }
 268
 269       bcopy (suffix, path + path_len, suffix_len);
 270       path_len += suffix_len;
 271     }
 272
 273   path[path_len] = '\0';
 274
 275   if (! file_p (path))
 276     {
 277       free (path);
 278       return NULL;
 279     }
 280
 281   return path;
 282 }
 283
 284
 285 static char *
 286 gethomedir ()
 287 {
 288   struct passwd *pw;
 289   char *ptr;
 290   char *copy;
 291
 292   if ((ptr = getenv ("HOME")) == NULL)
 293     {
 294       if ((ptr = getenv ("LOGNAME")) != NULL
 295           || (ptr = getenv ("USER")) != NULL)
 296         pw = getpwnam (ptr);
 297       else
 298         pw = getpwuid (getuid ());
 299
 300       if (pw)
 301         ptr = pw->pw_dir;
 302     }
 303
 304   if (ptr == NULL)
 305     return "/";
 306
 307   copy = (char *) malloc (strlen (ptr) + 2);
 308   strcpy (copy, ptr);
 309   strcat (copy, "/");
 310
 311   return copy;
 312 }
 313
 314
 315 static int
 316 file_p (path)
 317      char *path;
 318 {
 319   struct stat status;
 320
 321   return (access (path, 4) == 0                 /* exists and is readable */
 322           && stat (path, &status) == 0          /* get the status */
 323           && (S_ISDIR (status.st_mode)) == 0);  /* not a directory */
 324 }
 325
 326
 327 /* Find the first element of SEARCH_PATH which exists and is readable,
 328    after expanding the %-escapes.  Return 0 if we didn't find any, and
 329    the path name of the one we found otherwise.  */
 330
 331 static char *
 332 search_magic_path (search_path, class, escaped_suffix, suffix)
 333      char *search_path, *class, *escaped_suffix, *suffix;
 334 {
 335   register char *s, *p;
 336
 337   for (s = search_path; *s; s = p)
 338     {
 339       for (p = s; *p && *p != ':'; p++)
 340         ;
 341
 342       if (p > s)
 343         {
 344           char *path = magic_file_p (s, p - s, class, escaped_suffix, suffix);
 345           if (path)
 346             return path;
 347         }
 348       else if (*p == ':')
 349         {
 350           char *path;
 351
 352           s = "%N%S";
 353           path = magic_file_p (s, strlen (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   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 */