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     {
 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   int uid;
 286   struct passwd *pw;
 287   char *ptr;
 288   char *copy;
 289
 290   if ((ptr = getenv ("HOME")) == NULL)
 291     {
 292       if ((ptr = getenv ("USER")) != NULL)
 293         pw = getpwnam (ptr);
 294       else
 295         {
 296           uid = getuid ();
 297           pw = getpwuid (uid);
 298         }
 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           && (status.st_mode & S_IFDIR) == 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 == ':' && *(p + 1) == ':')
 343         {
 344           char *path;
 345
 346           s = "%N%S";
 347           path = magic_file_p (s, strlen (s), class, escaped_suffix, suffix);
 348           if (path)
 349             return path;
 350
 351           /* Skip the first colon.  */
 352           p++;
 353           continue;
 354         }
 355
 356       if (p > s)
 357         {
 358           char *path = magic_file_p (s, p - s, class, escaped_suffix, suffix);
 359           if (path)
 360             return path;
 361         }
 362
 363       if (*p == ':')
 364         p++;
 365     }
 366
 367   return 0;
 368 }
 369 \f
 370 /* Producing databases for individual sources.  */
 371
 372 #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"
 373
 374 static XrmDatabase
 375 get_system_app (class)
 376      char *class;
 377 {
 378   XrmDatabase db = NULL;
 379   char *path;
 380
 381   path = getenv ("XFILESEARCHPATH");
 382   if (! path) path = X_DEFAULT_SEARCH_PATH;
 383
 384   path = search_magic_path (path, class, 0, 0);
 385   if (path)
 386     {
 387       db = XrmGetFileDatabase (path);
 388       free (path);
 389     }
 390
 391   return db;
 392 }
 393
 394
 395 static XrmDatabase
 396 get_fallback (display)
 397      Display *display;
 398 {
 399   XrmDatabase db;
 400
 401   return NULL;
 402 }
 403
 404
 405 static XrmDatabase
 406 get_user_app (class)
 407      char *class;
 408 {
 409   char *path;
 410   char *file = 0;
 411
 412   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 413      names, not directories.  */
 414   if (((path = getenv ("XUSERFILESEARCHPATH"))
 415        && (file = search_magic_path (path, class, 0, 0)))
 416
 417       /* Check for APPLRESDIR; it is a path of directories.  In each,
 418          we have to search for LANG/CLASS and then CLASS.  */
 419       || ((path = getenv ("XAPPLRESDIR"))
 420           && ((file = search_magic_path (path, class, "/%L/%N", 0))
 421               || (file = search_magic_path (path, class, "/%N", 0))))
 422
 423       /* Check in the home directory.  This is a bit of a hack; let's
 424          hope one's home directory doesn't contain any %-escapes.  */
 425       || (path = gethomedir (),
 426           ((file = search_magic_path (path, class, "%L/%N", 0))
 427            || (file = search_magic_path (path, class, "%N", 0)))))
 428     {
 429       XrmDatabase db = XrmGetFileDatabase (file);
 430       free (file);
 431       return db;
 432     }
 433   else
 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 = 0;
 486
 487   if ((p = getenv ("XENVIRONMENT")) == NULL)
 488     {
 489       home = gethomedir ();
 490
 491       {
 492         int host_size = 100;
 493         host = (char *) malloc (host_size);
 494
 495         for (;;)
 496           {
 497             host[host_size - 1] = '\0';
 498             gethostname (host, host_size - 1);
 499             if (strlen (host) < host_size - 1)
 500               break;
 501             host = (char *) realloc (host, host_size *= 2);
 502           }
 503       }
 504
 505       path = (char *) malloc (strlen (home)
 506                               + sizeof (".Xdefaults-")
 507                               + strlen (host));
 508       sprintf (path, "%s%s%s", home, ".Xdefaults-", host);
 509       p = path;
 510     }
 511
 512   db = XrmGetFileDatabase (p);
 513
 514   if (path) free (path);
 515   if (home) free (home);
 516   if (host) free (host);
 517
 518   return db;
 519 }
 520 \f
 521 /* External interface.  */
 522
 523 /* Types of values that we can find in a database */
 524
 525 #define XrmStringType "String"  /* String representation */
 526 XrmRepresentation x_rm_string;  /* Quark representation */
 527
 528 /* Load X resources based on the display and a possible -xrm option. */
 529
 530 XrmDatabase
 531 x_load_resources (display, xrm_string, myname, myclass)
 532      Display *display;
 533      char *xrm_string, *myname, *myclass;
 534 {
 535   char *xdefs;
 536   XrmDatabase user_database;
 537   XrmDatabase rdb;
 538   XrmDatabase db;
 539
 540   x_rm_string = XrmStringToQuark (XrmStringType);
 541   XrmInitialize ();
 542   rdb = XrmGetStringDatabase ("");
 543
 544   user_database = get_user_db (display);
 545
 546   /* Figure out what the "customization string" is, so we can use it
 547      to decode paths.  */
 548   if (x_customization_string)
 549     free (x_customization_string);
 550   x_customization_string
 551     = x_get_customization_string (user_database, myname, myclass);
 552
 553   /* Get application system defaults */
 554   db = get_system_app (myclass);
 555   if (db != NULL)
 556     XrmMergeDatabases (db, &rdb);
 557
 558   /* Get Fallback resources */
 559   db = get_fallback (display);
 560   if (db != NULL)
 561     XrmMergeDatabases (db, &rdb);
 562
 563   /* Get application user defaults */
 564   db = get_user_app (myclass);
 565   if (db != NULL)
 566     XrmMergeDatabases (db, &rdb);
 567
 568   /* get User defaults */
 569   if (user_database != NULL)
 570     XrmMergeDatabases (user_database, &rdb);
 571
 572   /* Get Environment defaults. */
 573   db = get_environ_db ();
 574   if (db != NULL)
 575     XrmMergeDatabases (db, &rdb);
 576
 577   /* Last, merge in any specification from the command line. */
 578   if (xrm_string != NULL)
 579     {
 580       db = XrmGetStringDatabase (xrm_string);
 581       if (db != NULL)
 582         XrmMergeDatabases (db, &rdb);
 583     }
 584
 585   return rdb;
 586 }
 587
 588
 589 /* Retrieve the value of the resource specified by NAME with class CLASS
 590    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 591
 592 int
 593 x_get_resource (rdb, name, class, expected_type, ret_value)
 594      XrmDatabase rdb;
 595      char *name, *class;
 596      XrmRepresentation expected_type;
 597      XrmValue *ret_value;
 598 {
 599   XrmValue value;
 600   XrmName namelist[100];
 601   XrmClass classlist[100];
 602   XrmRepresentation type;
 603
 604   XrmStringToNameList(name, namelist);
 605   XrmStringToClassList(class, classlist);
 606
 607   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 608       && (type == expected_type))
 609     {
 610       if (type == x_rm_string)
 611         ret_value->addr = (char *) value.addr;
 612       else
 613         bcopy (value.addr, ret_value->addr, ret_value->size);
 614
 615       return value.size;
 616     }
 617
 618   return 0;
 619 }
 620
 621 /* Retrieve the string resource specified by NAME with CLASS from
 622    database RDB. */
 623
 624 char *
 625 x_get_string_resource (rdb, name, class)
 626      XrmDatabase rdb;
 627      char *name, *class;
 628 {
 629   XrmValue value;
 630
 631   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 632     return (char *) value.addr;
 633
 634   return (char *) 0;
 635 }
 636 \f
 637 /* Stand-alone test facilities.  */
 638
 639 #ifdef TESTRM
 640
 641 typedef char **List;
 642 #define arg_listify(len, list) (list)
 643 #define car(list) (*(list))
 644 #define cdr(list) (list + 1)
 645 #define NIL(list) (! *(list))
 646 #define free_arglist(list)
 647
 648 static List
 649 member (elt, list)
 650      char *elt;
 651      List list;
 652 {
 653   List p;
 654
 655   for (p = list; ! NIL (p); p = cdr (p))
 656     if (! strcmp (elt, car (p)))
 657       return p;
 658
 659   return p;
 660 }
 661
 662 static void
 663 fatal (msg, prog, x1, x2, x3, x4, x5)
 664     char *msg, *prog;
 665     int x1, x2, x3, x4, x5;
 666 {
 667     extern int errno;
 668
 669     if (errno)
 670       perror (prog);
 671
 672     (void) fprintf (stderr, msg, prog, x1, x2, x3, x4, x5);
 673     exit (1);
 674 }
 675
 676 main (argc, argv)
 677     int argc;
 678     char **argv;
 679 {
 680   Display *display;
 681   char *displayname, *resource_string, *class, *name;
 682   XrmDatabase xdb;
 683   List arg_list, lp;
 684
 685   arg_list = arg_listify (argc, argv);
 686
 687   lp = member ("-d", arg_list);
 688   if (!NIL (lp))
 689     displayname = car (cdr (lp));
 690   else
 691     displayname = "localhost:0.0";
 692
 693   lp = member ("-xrm", arg_list);
 694   if (! NIL (lp))
 695     resource_string = car (cdr (lp));
 696   else
 697     resource_string = (char *) 0;
 698
 699   lp = member ("-c", arg_list);
 700   if (! NIL (lp))
 701     class = car (cdr (lp));
 702   else
 703     class = "Emacs";
 704
 705   lp = member ("-n", arg_list);
 706   if (! NIL (lp))
 707     name = car (cdr (lp));
 708   else
 709     name = "emacs";
 710
 711   free_arglist (arg_list);
 712
 713   if (!(display = XOpenDisplay (displayname)))
 714     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 715
 716   xdb = x_load_resources (display, resource_string, name, class);
 717
 718   /* In a real program, you'd want to also do this: */
 719   display->db = xdb;
 720
 721   while (1)
 722     {
 723       char query_name[90];
 724       char query_class[90];
 725
 726       printf ("Name: ");
 727       gets (query_name);
 728
 729       if (strlen (query_name))
 730         {
 731           char *value;
 732
 733           printf ("Class: ");
 734           gets (query_class);
 735
 736           value = x_get_string_resource (xdb, query_name, query_class);
 737
 738           if (value != NULL)
 739             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 740           else
 741             printf ("\tNo Value.\n\n");
 742         }
 743       else
 744         break;
 745     }
 746   printf ("\tExit.\n\n");
 747
 748   XCloseDisplay (display);
 749 }
 750 #endif /* TESTRM */