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XrmGetResource(3X11)
X11R6
NAME
  XrmGetResource, XrmQGetResource, XrmQGetSearchList, XrmQGetSearchResource -
  retrieve database resources and search lists

SYNOPSIS
  Bool XrmGetResource(database, str_name, str_class, str_type_return,
  value_return)
	  XrmDatabase database;
	  char *str_name;
	  char *str_class;
	  char **str_type_return;
	  XrmValue *value_return;

  Bool XrmQGetResource(database, quark_name, quark_class, quark_type_return,
  value_return)
	  XrmDatabase database;
	  XrmNameList quark_name;
	  XrmClassList quark_class;
	  XrmRepresentation *quark_type_return;
	  XrmValue *value_return;

  typedef XrmHashTable *XrmSearchList;

  Bool XrmQGetSearchList(database, names, classes, list_return, list_length)
	  XrmDatabase database;
	  XrmNameList names;
	  XrmClassList classes;
	  XrmSearchList list_return;
	  int list_length;

  Bool XrmQGetSearchResource(list, name, class, type_return, value_return)
	  XrmSearchList list;
	  XrmName name;
	  XrmClass class;
	  XrmRepresentation *type_return;
	  XrmValue *value_return;

ARGUMENTS
  class
      Specifies the resource class.

  classes
      Specifies a list of resource classes.

  database
      Specifies the database that is to be used.

  list
      Specifies the search list returned by XrmQGetSearchList.

  list_length
      Specifies the number of entries (not the byte size) allocated for
      list_return.

  list_return
      Returns a search list for further use.

  name
      Specifies the resource name.

  names
      Specifies a list of resource names.

  quark_class
      Specifies the fully qualified class of the value being retrieved (as a
      quark).

  quark_name
      Specifies the fully qualified name of the value being retrieved (as a
      quark).

  quark_type_return
      Returns the representation type of the destination (as a quark).

  str_class
      Specifies the fully qualified class of the value being retrieved (as a
      string).

  str_name
      Specifies the fully qualified name of the value being retrieved (as a
      string).

  str_type_return
      Returns the representation type of the destination (as a string).

  type_return
      Returns data representation type.

  value_return
      Returns the value in the database.

DESCRIPTION
  The XrmGetResource and XrmQGetResource functions retrieve a resource from
  the specified database. Both take a fully qualified name/class pair, a
  destination resource representation, and the address of a value
  (size/address pair). The value and returned type point into database
  memory; therefore, you must not modify the data.

  The database only frees or overwrites entries on XrmPutResource,
  XrmQPutResource, or XrmMergeDatabases. A client that is not storing new
  values into the database or is not merging the database should be safe
  using the address passed back at any time until it exits. If a resource was
  found, both XrmGetResource and XrmQGetResource return True; otherwise, they
  return False.

  The XrmQGetSearchList function takes a list of names and classes and
  returns a list of database levels where a match might occur.	The returned
  list is in best-to-worst order and uses the same algorithm as
  XrmGetResource for determining precedence. If list_return was large enough
  for the search list, XrmQGetSearchList returns True; otherwise, it returns
  False.

  The size of the search list that the caller must allocate is dependent upon
  the number of levels and wildcards in the resource specifiers that are
  stored in the database. The worst case length is 3^n, where n is the number
  of name or class components in names or classes.

  When using XrmQGetSearchList followed by multiple probes for resources with
  a common name and class prefix, only the common prefix should be specified
  in the name and class list to XrmQGetSearchList.

  The XrmQGetSearchResource function searches the specified database levels
  for the resource that is fully identified by the specified name and class.
  The search stops with the first match.  XrmQGetSearchResource returns True
  if the resource was found; otherwise, it returns False.

  A call to XrmQGetSearchList with a name and class list containing all but
  the last component of a resource name followed by a call to
  XrmQGetSearchResource with the last component name and class returns the
  same database entry as XrmGetResource and XrmQGetResource with the fully
  qualified name and class.

MATCHING RULES
  The algorithm for determining which resource database entry matches a given
  query is the heart of the resource manager. All queries must fully specify
  the name and class of the desired resource (use of the characters "*" and
  "?" are not permitted). The library supports up to 100 components in a full
  name or class. Resources are stored in the database with only partially
  specified names and classes, using pattern matching constructs. An asterisk
  (*) is a loose binding and is used to represent any number of intervening
  components, including none. A period (.) is a tight binding and is used to
  separate immediately adjacent components. A question mark (?) is used to
  match any single component name or class. A database entry cannot end in a
  loose binding; the final component (which cannot be the character "?") must
  be specified. The lookup algorithm searches the database for the entry that
  most closely matches (is most specific for) the full name and class being
  queried. When more than one database entry matches the full name and class,
  precedence rules are used to select just one.

  The full name and class are scanned from left to right (from highest level
  in the hierarchy to lowest), one component at a time. At each level, the
  corresponding component and/or binding of each matching entry is
  determined, and these matching components and bindings are compared
  according to precedence rules. Each of the rules is applied at each level
  before moving to the next level, until a rule selects a single entry over
  all others. The rules, in order of precedence, are:

   1.  An entry that contains a matching component (whether name, class, or
       the character "?") takes precedence over entries that elide the level
       (that is, entries that match the level in a loose binding).

   2.  An entry with a matching name takes precedence over both entries with
       a matching class and entries that match using the character "?".	 An
       entry with a matching class takes precedence over entries that match
       using the character "?".

   3.  An entry preceded by a tight binding takes precedence over entries
       preceded by a loose binding.

SEE ALSO
  XrmInitialize(3X11), XrmMergeDatabases(3X11), XrmPutResource(3X11),
  XrmUniqueQuark(3X11)

  Xlib -- C Language X Interface

Index for Section 3X11

Alphabetical listing for X

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