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XrmGetResource(3)                              XLIB FUNCTIONS                              XrmGetResource(3)



NAME
       XrmGetResource, XrmQGetResource, XrmQGetSearchList, XrmQGetSearchResource - retrieve database
       resources and search lists

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

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

       typedef XrmHashTable *XrmSearchList;

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

       Bool XrmQGetSearchResource(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 XrmMerge-Databases. XrmMergeDatabases.
       Databases.  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 lev-els levels
       els where a match might occur.  The returned list is in best-to-worst order and uses the same algo-rithm algorithm
       rithm 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
       sup 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.  XrmQGet-SearchResource XrmQGetSearchResource
       SearchResource 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 repre-sent represent
       sent 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 low-est), lowest),
       est), 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



X Version 11                                    libX11 1.2.1                               XrmGetResource(3)