+<sect1>GRS-1
+<p>
+A GRS-1 record in <sf/IrTcl/ is represented as a list of elements.
+Each element specifies a tag as well as data. The data may
+be a subtree, which is represented as a list, and so on.
+
+The method <tt/getGrs/ is followed by a record index and
+optional specifiers that selects a specific sub-tree. Each element
+consists of 5 elements:
+
+<descrip>
+<tag>tag-set</tag> Tag set number.
+
+<tag>value-type</tag> Type of tag value. May be either
+<tt/numeric/ of <tt/string/.
+
+<tag>value</tag> The value it self.
+
+<tag>data-type</tag> May be either <tt/octets/, <tt/numeric/,
+<tt/ext/, <tt/string/, <tt/bool/, <tt/intUnit/, <tt/empty/,
+<tt/notRequested/, <tt/diagnostic/ or <tt/subtree/.
+
+<tag>data</tag>The data associated with element of given type as
+ indicated before. If data-type is <tt/numeric/ or <tt/string/
+ then data is encoded as a single Tcl token. The data-type <tt/bool/
+ is encoded as 0 or 1 for false and true respectively. If the
+ data-type is <tt/subtree/ the data is a sub-list.
+ In all other cases, the data is the empty string.
+</descrip>
+
+<bf/Example/
+
+Consider the GRS-1 record below as shown by the <bf/YAZ/ client program:
+
+<tscreen><verb>
+(1,1) OID: GILS-schema
+(1,14) 2
+(2,1) UTAH EARTHQUAKE EPICENTERS
+ class=4,type=1,value=us
+(4,52) UTAH GEOLOGICAL AND MINERAL SURVEY
+(3,Local-Subject-Index) APPALACHIAN VALLEY; EARTHQUAKE; EPICENTER
+(2,6)
+ (1,19) Five files of epicenter data arranged by ...
+ (3,Format) DIGITAL DATA SETS
+ (3,Data-Category) TERRESTRIAL
+ (3,Comments) Data are supplied by the University of Utah ...
+(4,70)
+ (4,90)
+ (2,10) UTAH GEOLOGICAL AND MINERAL SURVEY
+ (4,2) 606 BLACK HAWK WAY
+ (4,3) SALT LAKE CITY
+ (3,State) UT
+ (3,Zip-Code) 84108
+ (2,16) USA
+ (2,14) (801) 581-6831
+ (4,7) UTAH EARTHQUAKE EPICENTERS
+(4,1) ESDD0006
+(1,16) 198903
+</verb></tscreen>
+
+The record may be fetched from the result set, <tt/z.1/, at position 1
+by using:
+<tscreen><verb>
+z.1 getGrs 1
+</verb></tscreen>
+which will return:
+<tscreen><verb>
+{ 1 numeric 1 oid 1.2.840.10003.13.2 }
+{ 1 numeric 14 string 2 }
+{ 2 numeric 1 string
+ { UTAH EARTHQUAKE EPICENTERS} }
+{ 4 numeric 52 string {UTAH GEOLOGICAL AND MINERAL SURVEY} }
+{ 3 string Local-Subject-Index string
+ {APPALACHIAN VALLEY; EARTHQUAKE; EPICENTER} }
+{ 2 numeric 6 subtree
+ { { 1 numeric 19 string
+ {Five files of epicenter data arranged by ...} }
+ { 3 string Format string {DIGITAL DATA SETS} }
+ { 3 string Data-Category string TERRESTRIAL }
+ { 3 string Comments string
+ {Data are supplied by the University of Utah ...} } } }
+{ 4 numeric 70 subtree
+ { { 4 numeric 90 subtree
+ { { 2 numeric 10 string
+ {UTAH GEOLOGICAL AND MINERAL SURVEY} }
+ { 4 numeric 2 string {606 BLACK HAWK WAY} }
+ { 4 numeric 3 string {SALT LAKE CITY} }
+ { 3 string State string UT }
+ { 3 string Zip-Code string 84108 }
+ { 2 numeric 16 string USA }
+ { 2 numeric 14 string {(801) 581-6831} } } }
+ { 4 numeric 7 string {UTAH EARTHQUAKE EPICENTERS} } } }
+{ 4 numeric 1 string ESDD0006 }
+{ 1 numeric 16 string 198903 }
+</verb></tscreen>
+
+We can choose only to get the path (2,6) by using:
+
+<tscreen><verb>
+z.1 getGrs 1 (2,6)
+</verb></tscreen>
+and we'll get:
+<tscreen><verb>
+{ 2 numeric 6 subtree { { 1 numeric 19 string
+ {Five files of epicenter data arranged by ...} }
+ { 3 string Format string {DIGITAL DATA SETS} }
+ { 3 string Data-Category string TERRESTRIAL }
+ { 3 string Comments
+ string {Data are supplied by the University of Utah ...} } } }
+</verb></tscreen>
+
+To get the well known (1,19) within the subject (2,6) we use
+<tscreen><verb>
+z.1 getGrs 1 (2,6) (1,19)
+</verb></tscreen>
+and get:
+<tscreen><verb>
+{ 2 numeric 6 subtree
+ { { 1 numeric 19 string
+ {Five files of epicenter data arranged by ...} } } }
+</verb></tscreen>
+<bf/End of example/
+
+<sect1>Explain
+<p>
+Explain records are retrieved like other records. The method,
+<tt>getExplain</tt> is followed by an index and and an optional
+Explain record pattern.
+
+The returned record is a canonical representation of the Explain record.
+An ASN.1 sequence is represented as a list. Each item in the list
+consists of the name of the element, followed by its value if the value
+is supplied.
+
+The optional pattern that follows the index after <tt>getExplain</tt>
+consists of one or more elements, that is matched against the elements
+of the actual record.
+
+<bf/Example/
+
+One of the few targets that support explain is the ATT research server
+at <tt>z3950.research.att.com</tt>.
+
+The targetInfo record was returned by the target and it's stored in
+position 1 in the result set, <tt>z.1</tt>. To retrieve the whole
+record we must use
+<tscreen><verb>
+z.1 getExplain 1
+</verb></tscreen>
+
+and we get in return
+
+<tscreen><verb>
+{targetInfo commonInfo {name {Lucent Technologies Research Server}}
+recentNews icon {namedResultSets 1} {multipleDBsearch 0}
+{maxResultSets 100} {maxResultSize 600000} maxTerms timeoutInterval
+{welcomeMessage {strings { {language eng}
+{text
+{Salutations - this is Lucent Technologies experimental Z39.50 server.
+No guarentees, but free and unlimited access!}} } } }
+{contactInfo {name {Robert Waldstein}} {description {strings
+{ {language eng}
+{text {Librarian system designer - no legal anythings}} } } }
+{address {strings { {language eng} {text {Room 3D-591
+600 Mountain Ave
+Murray Hill
+N.J. USA 07974}} } } } {email wald@lucent.com} {phone {908 582-6171}} }
+description nicknames {usageRest {strings { {language eng}
+{text {None - as long as nonProfit research}} } } } paymentAddr
+{hours {strings { {language eng} {text {Should never be down}} } } }
+dbCombinations addresses commonAccessInfo }
+</verb></tscreen>
+
+The <tt>targetInfo</tt> above indicates the the record is really a
+<tt>targetInfo</tt> record. The <tt>commonInfo</tt>, which is optional, is
+not supplied by this server. The <tt>name</tt>, however is supplied,
+with the value <tt>Lucent Technologies Research Server</tt>.
+
+To retrieve the <tt>contactInfo</tt> from the record above we can
+extract the element from the record by using Tcl's list manipulation
+facilities, for example by doing
+<tscreen><verb>
+set ti [z.1 getExplain 1]
+lindex [lindex $ti 0] 12
+</verb></tscreen>
+which will return
+<tscreen><verb>
+contactInfo {name {Robert Waldstein}} {description {strings
+{ {language eng}
+{text {Librarian system designer - no legal anythings}} }
+} } {address {strings { {language eng} {text {Room 3D-591
+600 Mountain Ave
+Murray Hill
+N.J. USA 07974}} } } } {email wald@lucent.com} {phone {908 582-6171}}
+</verb></tscreen>
+
+We can also extract almost the same by doing
+<tscreen><verb>
+z.1 getExplain 1 targetInfo contactInfo
+</verb></tscreen>
+which will return
+<tscreen><verb>
+{name {Robert Waldstein}} {description {strings { {language eng}
+{text {Librarian system designer - no legal anythings}} } } }
+{address {strings { {language eng} {text {Room 3D-591
+600 Mountain Ave
+Murray Hill
+N.J. USA 07974}} } } } {email wald@lucent.com} {phone {908 582-6171}}
+</verb></tscreen>
+
+<bf/End of example/
+
projects / ir-tcl-moved-to-github.git / blobdiff