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 #ifdef HAVE_UNISTD_H
  28 #include <unistd.h>
  29 #endif
  30
  31 #include <paths.h>
  32
  33 #include <stdio.h>
  34
  35 #if 1 /* I'd really appreciate it if this code could go away...  -JimB */
  36 /* this avoids lossage in the `dual-universe' headers on AT&T SysV X11 */
  37 #ifdef USG5
  38 #ifndef SYSV
  39 #define SYSV
  40 #endif
  41 #include <unistd.h>
  42 #endif /* USG5 */
  43
  44 #endif /* 1 */
  45
  46 #include <X11/Xlib.h>
  47 #include <X11/Xatom.h>
  48 #if 0
  49 #include <X11/Xos.h>
  50 #endif
  51 #include <X11/X.h>
  52 #include <X11/Xutil.h>
  53 #include <X11/Xresource.h>
  54 #ifdef VMS
  55 #include "vms-pwd.h"
  56 #else
  57 #include <pwd.h>
  58 #endif
  59 #include <sys/stat.h>
  60
  61 #if !defined(S_ISDIR) && defined(S_IFDIR)
  62 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  63 #endif
  64
  65 extern char *getenv ();
  66
  67 /* This does cause trouble on AIX.  I'm going to take the comment at
  68    face value.  */
  69 #if 0
  70 extern short getuid ();         /* If this causes portability problems,
  71                                    I think we should just delete it; it'll
  72                                    default to `int' anyway.  */
  73 #endif
  74
  75 #ifdef DECLARE_GETPWUID_WITH_UID_T
  76 extern struct passwd *getpwuid (uid_t);
  77 extern struct passwd *getpwnam (const char *);
  78 #else
  79 extern struct passwd *getpwuid ();
  80 extern struct passwd *getpwnam ();
  81 #endif
  82
  83 extern char *get_system_name ();
  84
  85 /* Make sure not to #include anything after these definitions.  Let's
  86    not step on anyone's prototypes.  */
  87 #ifdef emacs
  88 #define malloc xmalloc
  89 #define realloc xrealloc
  90 #define free xfree
  91 extern long *xmalloc (), *xrealloc ();
  92 #endif
  93
  94 char *x_get_string_resource ();
  95 static int file_p ();
  96
  97 \f
  98 /* X file search path processing.  */
  99
 100
 101 /* The string which gets substituted for the %C escape in XFILESEARCHPATH
 102    and friends, or zero if none was specified.  */
 103 char *x_customization_string;
 104
 105
 106 /* Return the value of the emacs.customization (Emacs.Customization)
 107    resource, for later use in search path decoding.  If we find no
 108    such resource, return zero.  */
 109 char *
 110 x_get_customization_string (db, name, class)
 111      XrmDatabase db;
 112      char *name, *class;
 113 {
 114   char *full_name
 115     = (char *) alloca (strlen (name) + sizeof ("customization") + 3);
 116   char *full_class
 117     = (char *) alloca (strlen (class) + sizeof ("Customization") + 3);
 118   char *result;
 119
 120   sprintf (full_name,  "%s.%s", name,  "customization");
 121   sprintf (full_class, "%s.%s", class, "Customization");
 122
 123   result = x_get_string_resource (db, full_name, full_class);
 124
 125   if (result)
 126     {
 127       char *copy = (char *) malloc (strlen (result) + 1);
 128       strcpy (copy, result);
 129       return copy;
 130     }
 131   else
 132     return 0;
 133 }
 134
 135
 136 /* Expand all the Xt-style %-escapes in STRING, whose length is given
 137    by STRING_LEN.  Here are the escapes we're supposed to recognize:
 138
 139         %N      The value of the application's class name
 140         %T      The value of the type parameter ("app-defaults" in this
 141                 context)
 142         %S      The value of the suffix parameter ("" in this context)
 143         %L      The language string associated with the specified display
 144                 (We use the "LANG" environment variable here, if it's set.)
 145         %l      The language part of the display's language string
 146                 (We treat this just like %L.  If someone can tell us what
 147                  we're really supposed to do, dandy.)
 148         %t      The territory part of the display's language string
 149                 (This never gets used.)
 150         %c      The codeset part of the display's language string
 151                 (This never gets used either.)
 152         %C      The customization string retrieved from the resource
 153                 database associated with display.
 154                 (This is x_customization_string.)
 155
 156    Return the expanded file name if it exists and is readable, and
 157    refers to %L only when the LANG environment variable is set, or
 158    otherwise provided by X.
 159
 160    ESCAPED_SUFFIX and SUFFIX are postpended to STRING if they are
 161    non-zero.  %-escapes in ESCAPED_SUFFIX are expanded; STRING is left
 162    alone.
 163
 164    Return NULL otherwise.  */
 165
 166 static char *
 167 magic_file_p (string, string_len, class, escaped_suffix, suffix)
 168      char *string;
 169      int string_len;
 170      char *class, *escaped_suffix, *suffix;
 171 {
 172   char *lang = getenv ("LANG");
 173
 174   int path_size = 100;
 175   char *path = (char *) malloc (path_size);
 176   int path_len = 0;
 177
 178   char *p = string;
 179
 180   while (p < string + string_len)
 181     {
 182       /* The chunk we're about to stick on the end of result.  */
 183       char *next;
 184       int next_len;
 185
 186       if (*p == '%')
 187         {
 188           p++;
 189
 190           if (p >= string + string_len)
 191             next_len = 0;
 192           else
 193             switch (*p)
 194               {
 195               case '%':
 196                 next = "%";
 197                 next_len = 1;
 198                 break;
 199
 200               case 'C':
 201                 next = (x_customization_string
 202                         ? x_customization_string
 203                         : "");
 204                 next_len = strlen (next);
 205                 break;
 206
 207               case 'N':
 208                 next = class;
 209                 next_len = strlen (class);
 210                 break;
 211
 212               case 'T':
 213                 next = "app-defaults";
 214                 next_len = strlen (next);
 215                 break;
 216
 217               default:
 218               case 'S':
 219                 next_len = 0;
 220                 break;
 221
 222               case 'L':
 223               case 'l':
 224                 if (! lang)
 225                   {
 226                     free (path);
 227                     return NULL;
 228                   }
 229
 230                 next = lang;
 231                 next_len = strlen (next);
 232                 break;
 233
 234               case 't':
 235               case 'c':
 236                 free (path);
 237                 return NULL;
 238               }
 239         }
 240       else
 241         next = p, next_len = 1;
 242
 243       /* Do we have room for this component followed by a '\0' ?  */
 244       if (path_len + next_len + 1 > path_size)
 245         {
 246           path_size = (path_len + next_len + 1) * 2;
 247           path = (char *) realloc (path, path_size);
 248         }
 249
 250       bcopy (next, path + path_len, next_len);
 251       path_len += next_len;
 252
 253       p++;
 254
 255       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 256       if (p >= string + string_len && escaped_suffix)
 257         {
 258           string = escaped_suffix;
 259           string_len = strlen (string);
 260           p = string;
 261           escaped_suffix = NULL;
 262         }
 263     }
 264
 265   /* Perhaps we should add the SUFFIX now.  */
 266   if (suffix)
 267     {
 268       int suffix_len = strlen (suffix);
 269
 270       if (path_len + suffix_len + 1 > path_size)
 271         {
 272           path_size = (path_len + suffix_len + 1);
 273           path = (char *) realloc (path, path_size);
 274         }
 275
 276       bcopy (suffix, path + path_len, suffix_len);
 277       path_len += suffix_len;
 278     }
 279
 280   path[path_len] = '\0';
 281
 282   if (! file_p (path))
 283     {
 284       free (path);
 285       return NULL;
 286     }
 287
 288   return path;
 289 }
 290
 291
 292 static char *
 293 gethomedir ()
 294 {
 295   struct passwd *pw;
 296   char *ptr;
 297   char *copy;
 298
 299   if ((ptr = getenv ("HOME")) == NULL)
 300     {
 301       if ((ptr = getenv ("LOGNAME")) != NULL
 302           || (ptr = getenv ("USER")) != NULL)
 303         pw = getpwnam (ptr);
 304       else
 305         pw = getpwuid (getuid ());
 306
 307       if (pw)
 308         ptr = pw->pw_dir;
 309     }
 310
 311   if (ptr == NULL)
 312     return "/";
 313
 314   copy = (char *) malloc (strlen (ptr) + 2);
 315   strcpy (copy, ptr);
 316   strcat (copy, "/");
 317
 318   return copy;
 319 }
 320
 321
 322 static int
 323 file_p (path)
 324      char *path;
 325 {
 326   struct stat status;
 327
 328   return (access (path, 4) == 0                 /* exists and is readable */
 329           && stat (path, &status) == 0          /* get the status */
 330           && (S_ISDIR (status.st_mode)) == 0);  /* not a directory */
 331 }
 332
 333
 334 /* Find the first element of SEARCH_PATH which exists and is readable,
 335    after expanding the %-escapes.  Return 0 if we didn't find any, and
 336    the path name of the one we found otherwise.  */
 337
 338 static char *
 339 search_magic_path (search_path, class, escaped_suffix, suffix)
 340      char *search_path, *class, *escaped_suffix, *suffix;
 341 {
 342   register char *s, *p;
 343
 344   for (s = search_path; *s; s = p)
 345     {
 346       for (p = s; *p && *p != ':'; p++)
 347         ;
 348
 349       if (p > s)
 350         {
 351           char *path = magic_file_p (s, p - s, class, escaped_suffix, suffix);
 352           if (path)
 353             return path;
 354         }
 355       else if (*p == ':')
 356         {
 357           char *path;
 358
 359           s = "%N%S";
 360           path = magic_file_p (s, strlen (s), class, escaped_suffix, suffix);
 361           if (path)
 362             return path;
 363         }
 364
 365       if (*p == ':')
 366         p++;
 367     }
 368
 369   return 0;
 370 }
 371 \f
 372 /* Producing databases for individual sources.  */
 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 = PATH_X_DEFAULTS;
 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   char *free_it = 0;
 412
 413   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 414      names, not directories.  */
 415   if (((path = getenv ("XUSERFILESEARCHPATH"))
 416        && (file = search_magic_path (path, class, 0, 0)))
 417
 418       /* Check for APPLRESDIR; it is a path of directories.  In each,
 419          we have to search for LANG/CLASS and then CLASS.  */
 420       || ((path = getenv ("XAPPLRESDIR"))
 421           && ((file = search_magic_path (path, class, "/%L/%N", 0))
 422               || (file = search_magic_path (path, class, "/%N", 0))))
 423
 424       /* Check in the home directory.  This is a bit of a hack; let's
 425          hope one's home directory doesn't contain any %-escapes.  */
 426       || (free_it = gethomedir (),
 427           ((file = search_magic_path (free_it, class, "%L/%N", 0))
 428            || (file = search_magic_path (free_it, class, "%N", 0)))))
 429     {
 430       XrmDatabase db = XrmGetFileDatabase (file);
 431       free (file);
 432       if (free_it)
 433         free (free_it);
 434       return db;
 435     }
 436
 437   if (free_it)
 438     free (free_it);
 439   return NULL;
 440 }
 441
 442
 443 static XrmDatabase
 444 get_user_db (display)
 445      Display *display;
 446 {
 447   XrmDatabase db;
 448   char *xdefs;
 449
 450 #ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
 451   xdefs = XResourceManagerString (display);
 452 #else
 453   xdefs = display->xdefaults;
 454 #endif
 455
 456   if (xdefs != NULL)
 457     db = XrmGetStringDatabase (xdefs);
 458   else
 459     {
 460       char *home;
 461       char *xdefault;
 462
 463       home = gethomedir ();
 464       xdefault = (char *) malloc (strlen (home) + sizeof (".Xdefaults"));
 465       strcpy (xdefault, home);
 466       strcat (xdefault, ".Xdefaults");
 467       db = XrmGetFileDatabase (xdefault);
 468       free (home);
 469       free (xdefault);
 470     }
 471
 472 #ifdef HAVE_XSCREENRESOURCESTRING
 473   /* Get the screen-specific resources too.  */
 474   xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
 475   if (xdefs != NULL)
 476     {
 477       XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
 478       XFree (xdefs);
 479     }
 480 #endif
 481
 482   return db;
 483 }
 484
 485 static XrmDatabase
 486 get_environ_db ()
 487 {
 488   XrmDatabase db;
 489   char *p;
 490   char *path = 0, *home = 0, *host;
 491
 492   if ((p = getenv ("XENVIRONMENT")) == NULL)
 493     {
 494       home = gethomedir ();
 495       host = get_system_name ();
 496       path = (char *) malloc (strlen (home)
 497                               + sizeof (".Xdefaults-")
 498                               + strlen (host));
 499       sprintf (path, "%s%s%s", home, ".Xdefaults-", host);
 500       p = path;
 501     }
 502
 503   db = XrmGetFileDatabase (p);
 504
 505   if (path) free (path);
 506   if (home) free (home);
 507
 508   return db;
 509 }
 510 \f
 511 /* External interface.  */
 512
 513 /* Types of values that we can find in a database */
 514
 515 #define XrmStringType "String"  /* String representation */
 516 XrmRepresentation x_rm_string;  /* Quark representation */
 517
 518 /* Load X resources based on the display and a possible -xrm option. */
 519
 520 XrmDatabase
 521 x_load_resources (display, xrm_string, myname, myclass)
 522      Display *display;
 523      char *xrm_string, *myname, *myclass;
 524 {
 525   char *xdefs;
 526   XrmDatabase user_database;
 527   XrmDatabase rdb;
 528   XrmDatabase db;
 529
 530   x_rm_string = XrmStringToQuark (XrmStringType);
 531 #ifndef USE_X_TOOLKIT
 532   /* pmr@osf.org says this shouldn't be done if USE_X_TOOLKIT.
 533      I suspect it's because the toolkit version does this elsewhere.  */
 534   XrmInitialize ();
 535 #endif
 536   rdb = XrmGetStringDatabase ("");
 537
 538   user_database = get_user_db (display);
 539
 540   /* Figure out what the "customization string" is, so we can use it
 541      to decode paths.  */
 542   if (x_customization_string)
 543     free (x_customization_string);
 544   x_customization_string
 545     = x_get_customization_string (user_database, myname, myclass);
 546
 547   /* Get application system defaults */
 548   db = get_system_app (myclass);
 549   if (db != NULL)
 550     XrmMergeDatabases (db, &rdb);
 551
 552   /* Get Fallback resources */
 553   db = get_fallback (display);
 554   if (db != NULL)
 555     XrmMergeDatabases (db, &rdb);
 556
 557   /* Get application user defaults */
 558   db = get_user_app (myclass);
 559   if (db != NULL)
 560     XrmMergeDatabases (db, &rdb);
 561
 562   /* get User defaults */
 563   if (user_database != NULL)
 564     XrmMergeDatabases (user_database, &rdb);
 565
 566   /* Get Environment defaults. */
 567   db = get_environ_db ();
 568   if (db != NULL)
 569     XrmMergeDatabases (db, &rdb);
 570
 571   /* Last, merge in any specification from the command line. */
 572   if (xrm_string != NULL)
 573     {
 574       db = XrmGetStringDatabase (xrm_string);
 575       if (db != NULL)
 576         XrmMergeDatabases (db, &rdb);
 577     }
 578
 579   return rdb;
 580 }
 581
 582
 583 /* Retrieve the value of the resource specified by NAME with class CLASS
 584    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 585
 586 int
 587 x_get_resource (rdb, name, class, expected_type, ret_value)
 588      XrmDatabase rdb;
 589      char *name, *class;
 590      XrmRepresentation expected_type;
 591      XrmValue *ret_value;
 592 {
 593   XrmValue value;
 594   XrmName namelist[100];
 595   XrmClass classlist[100];
 596   XrmRepresentation type;
 597
 598   XrmStringToNameList(name, namelist);
 599   XrmStringToClassList(class, classlist);
 600
 601   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 602       && (type == expected_type))
 603     {
 604       if (type == x_rm_string)
 605         ret_value->addr = (char *) value.addr;
 606       else
 607         bcopy (value.addr, ret_value->addr, ret_value->size);
 608
 609       return value.size;
 610     }
 611
 612   return 0;
 613 }
 614
 615 /* Retrieve the string resource specified by NAME with CLASS from
 616    database RDB. */
 617
 618 char *
 619 x_get_string_resource (rdb, name, class)
 620      XrmDatabase rdb;
 621      char *name, *class;
 622 {
 623   XrmValue value;
 624
 625   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 626     return (char *) value.addr;
 627
 628   return (char *) 0;
 629 }
 630 \f
 631 /* Stand-alone test facilities.  */
 632
 633 #ifdef TESTRM
 634
 635 typedef char **List;
 636 #define arg_listify(len, list) (list)
 637 #define car(list) (*(list))
 638 #define cdr(list) (list + 1)
 639 #define NIL(list) (! *(list))
 640 #define free_arglist(list)
 641
 642 static List
 643 member (elt, list)
 644      char *elt;
 645      List list;
 646 {
 647   List p;
 648
 649   for (p = list; ! NIL (p); p = cdr (p))
 650     if (! strcmp (elt, car (p)))
 651       return p;
 652
 653   return p;
 654 }
 655
 656 static void
 657 fatal (msg, prog, x1, x2, x3, x4, x5)
 658     char *msg, *prog;
 659     int x1, x2, x3, x4, x5;
 660 {
 661     extern int errno;
 662
 663     if (errno)
 664       perror (prog);
 665
 666     (void) fprintf (stderr, msg, prog, x1, x2, x3, x4, x5);
 667     exit (1);
 668 }
 669
 670 main (argc, argv)
 671     int argc;
 672     char **argv;
 673 {
 674   Display *display;
 675   char *displayname, *resource_string, *class, *name;
 676   XrmDatabase xdb;
 677   List arg_list, lp;
 678
 679   arg_list = arg_listify (argc, argv);
 680
 681   lp = member ("-d", arg_list);
 682   if (!NIL (lp))
 683     displayname = car (cdr (lp));
 684   else
 685     displayname = "localhost:0.0";
 686
 687   lp = member ("-xrm", arg_list);
 688   if (! NIL (lp))
 689     resource_string = car (cdr (lp));
 690   else
 691     resource_string = (char *) 0;
 692
 693   lp = member ("-c", arg_list);
 694   if (! NIL (lp))
 695     class = car (cdr (lp));
 696   else
 697     class = "Emacs";
 698
 699   lp = member ("-n", arg_list);
 700   if (! NIL (lp))
 701     name = car (cdr (lp));
 702   else
 703     name = "emacs";
 704
 705   free_arglist (arg_list);
 706
 707   if (!(display = XOpenDisplay (displayname)))
 708     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 709
 710   xdb = x_load_resources (display, resource_string, name, class);
 711
 712   /* In a real program, you'd want to also do this: */
 713   display->db = xdb;
 714
 715   while (1)
 716     {
 717       char query_name[90];
 718       char query_class[90];
 719
 720       printf ("Name: ");
 721       gets (query_name);
 722
 723       if (strlen (query_name))
 724         {
 725           char *value;
 726
 727           printf ("Class: ");
 728           gets (query_class);
 729
 730           value = x_get_string_resource (xdb, query_name, query_class);
 731
 732           if (value != NULL)
 733             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 734           else
 735             printf ("\tNo Value.\n\n");
 736         }
 737       else
 738         break;
 739     }
 740   printf ("\tExit.\n\n");
 741
 742   XCloseDisplay (display);
 743 }
 744 #endif /* TESTRM */