HP OpenVMS Systems Documentation

Translates a logical name and returns the equivalence name string or the requested attributes of the logical name specified.

Format

F$TRNLNM (logical-name [,table] [,index] [,mode] [,case] [,item])

Return Value

Arguments

logical-name

Specifies a character string containing the logical name to be translated.

table

Specifies a character string containing the logical name table or tables that the F$TRNLNM function should search to translate the logical name. The table argument must be a logical name that translates to a logical name table or to a list of table names.

A logical name for a logical name table must be defined in one of the following logical name tables:

• LNM$SYSTEM_DIRECTORY
• LNM$PROCESS_DIRECTORY

Note If you subsequently create a table using the CREATE/NAME_TABLE command and want to make your private table accessible for F$TRNLNM, you must redefine one of the table logical names to include your private table. To see all the tables that are normally searched by F$TRNLNM, issue the following command: $ SHOW LOGICAL/STRUCTURE LNM$DCL_LOGICAL For more information, see the CREATE/NAME_TABLE amd SHOW LOGICAL commands.

If you do not specify a table, the default value is LNM$DCL_LOGICAL. That is, the F$TRNLNM function searches the tables whose names are equated to the logical name LNM$DCL_LOGICAL. Unless LNM$DCL_LOGICAL has been redefined for your process, the F$TRNLNM function searches the process, job, group, and system logical name tables, in that order, and returns the equivalence name for the first match found.

index

Specifies the number of the equivalence name to be returned if the logical name has more than one translation. The index refers to the equivalence strings in the order the names were listed when the logical name was defined.

The index begins with zero; that is, the first name in a list of equivalence names is referenced by the index zero.

If you do not specify the index argument, the default is zero.

mode

Specifies a character string containing one of the following access modes for the translation: USER (default), SUPERVISOR, EXECUTIVE, or KERNEL.

The F$TRNLNM function starts by searching for a logical name created with the access mode specified in the mode argument. If it does not find a match, the F$TRNLNM function searches for the name created with each inner access mode and returns the first match found. For example, two logical names can have the same name, but one name can be created with user access mode and the other name with executive access mode. If the mode argument is USER, the F$TRNLNM function returns the equivalence string for the user-mode, not the executive-mode, logical name.

case

Specifies the type of translation to be performed. The case argument controls both the case of the translation and whether the translation is to be interlocked or noninterlocked.

You can specify the case argument as any combination of CASE_BLIND (default), CASE_SENSITIVE, NONINTERLOCKED (default), and INTERLOCKED.

If the translation is case blind, the F$TRNLNM searches the logical name table for the first occurrence of the logical name, regardless of the case, and returns the translation. If no match is found for either case, the function returns a null string ("").

If the translation is case sensitive, the F$TRNLNM function searches only for a logical name with characters of the same case as the logical-name argument. If no exact match is found, the F$TRNLNM function returns a null string ("").

If the translation is interlocked, the F$TRNLNM function does not take effect until all clusterwide logical name modifications in progress complete. Then, if a match is found, the result of the translation is returned. If no match is found, the F$TRNLNM function returns a null string ("").

If the translation is noninterlocked, the F$TRNLNM function takes effect immediately. If a match is found, the result of the translation is returned. If no match is found, the F$TRNLNM function returns a null string ("").

item

Specifies a character string containing the type of information that F$TRNLNM should return about the specified logical name. Specify one of the following items:

Item	Return Type	Information Returned
ACCESS_MODE	String	One of the following access modes associated with the logical name: USER, SUPERVISOR, EXECUTIVE, KERNEL.
CLUSTERWIDE	String	TRUE or FALSE to indicate whether the logical name is in a clusterwide name table.
CONCEALED	String	TRUE or FALSE to indicate whether the CONCEALED attribute was specified with the /TRANSLATION_ATTRIBUTES qualifier when the logical name was created. The CONCEALED attribute is used to create a concealed logical name.
CONFINE	String	TRUE or FALSE to indicate whether the logical name is confined. If the logical name is confined (TRUE), then the name is not copied to subprocesses. If the logical name is not confined (FALSE), then the name is copied to subprocesses.
CRELOG	String	TRUE or FALSE to indicate whether the logical name was created with the $CRELOG system service or with the $CRELNM system service, using the CRELOG attribute. If the logical name was created with the $CRELOG system service or with the $CRELNM system service, using the CRELOG attribute, then TRUE is returned. Otherwise, FALSE is returned.
LENGTH	Integer	Length of the equivalence name associated with the specified logical name. If the logical name has more than one equivalence name, the F$TRNLNM function returns the length of the name specified by the index argument.
MAX_INDEX	Integer	The largest index defined for the logical name. The index shows how many equivalence names are associated with a logical name. The index is zero based; that is, the index zero refers to the first name in a list of equivalence names.
NO_ALIAS	String	TRUE or FALSE to indicate whether the logical name has the NO_ALIAS attribute. The NO_ALIAS attribute means that a logical name must be unique within outer access mode.
TABLE	String	TRUE or FALSE to indicate whether the logical name is the name of a logical name table.
TABLE_NAME	String	Name of the table where the logical name was found.
TERMINAL	String	TRUE or FALSE to indicate whether the TERMINAL attribute was specified with the /TRANSLATION_ATTRIBUTES qualifier when the logical name was created. The TERMINAL attribute indicates that the logical name is not a candidate for iterative translation.
VALUE	String	Default. The equivalence name associated with the specified logical name. If the logical name has more than one equivalence name, the F$TRNLNM function returns the name specified by the index argument.

Description

The lexical function F$TRNLNM uses the $TRNLNM system service to translate a logical name and return the equivalence name string, or the requested attributes of the logical name specified. The translation is not iterative; the equivalence string is not checked to determine whether it is a logical name.

When you use the F$TRNLNM function, you can omit optional arguments that can be used to the right of the last argument you specify. However, you must include commas (,) as placeholders if you omit optional arguments to the left of the last argument that you specify.

You can use the F$TRNLNM function in command procedures to save the current equivalence of a logical name and later restore it. You can also use it to test whether logical names have been assigned.

Examples

$ SAVE_DIR = F$TRNLNM("SYS$DISK")+F$DIRECTORY() 
   .
   .
   .
$ SET DEFAULT 'SAVE_DIR' 
      

The assignment statement concatenates the values returned by the F$DIRECTORY and F$TRNLNM functions, and assigns the resulting string to the symbol SAVE_DIR. The symbol SAVE_DIR consists of a full device and directory name string.

The argument SYS$DISK is enclosed in quotation marks ("") because it is a character string. (The command interpreter treats all arguments that begin with alphabetic characters as symbols or lexical functions, unless the arguments are enclosed in quotation marks.) None of the optional arguments is specified, so the F$TRNLNM function uses the defaults.

At the end of the command procedure, the original default directory is reset. When you reset the directory, you must place single quotation marks (` ') around the symbol SAVE_DIR to force symbol substitution.

$ DEFINE/TABLE=LNM$GROUP TERMINAL 'F$TRNLNM("SYS$OUTPUT")' 
      

This example shows a line from a command procedure that (1) uses the F$TRNLNM function to determine the name of the current output device and (2) creates a group logical name table entry based on the equivalence string.

You must enclose the argument SYS$OUTPUT in quotation marks because it is a character string.

Also, in this example you must enclose the F$TRNLNM function in single quotation marks to force the lexical function to be evaluated; otherwise, the DEFINE command does not automatically evaluate the lexical function.

$ RESULT= -
_$ F$TRNLNM("INFILE","LNM$PROCESS",0,"SUPERVISOR",,"NO_ALIAS")
$ SHOW SYMBOL RESULT
  RESULT = "FALSE"
      

In this example, the F$TRNLNM function searches the process logical name table for the logical name INFILE. The function starts the search by looking for the logical name INFILE created in supervisor mode. If no match is found, the function looks for INFILE created in executive mode.

When a match is found, the F$TRNLNM function determines whether the name INFILE was created with the NO_ALIAS attribute. In this case, the NO_ALIAS attribute is not specified.

$ foo=f$trnlnm("FOO","LNM$SYSCLUSTER",,,"INTERLOCKED",) 
      

In this example, logical name FOO is translated in the LNM$SYSCLUSTER table in an interlocked manner; that is, all clusterwide logical name modifications in progress on this and other nodes are completed before the translation occurs. This ensures that the translation is based on the most recent definition of FOO.

Because the case translation is not specified, the translation is by default CASE_BLIND.

$ foo=f$trnlnm("FOO","LNM$SYSCLUSTER",,,"INTERLOCKED,CASE_SENSITIVE",) 
      

This example specifies both case sensitive and interlocked translation.