PARSEC Technical Information

The DCL HELP facility entries for Lexicals (all the F$* Lexical Functions) is organized alphabetically, not by function or category. Here's another way of listing these Lexicals, this time by category (roughly, by function).

F$INTEGER( arg )
  Converts its argument to an actual 32-bit integer, if possible.
  The argument can be a string of characters which represents an
  integer value, or an integer expression.

F$EDIT( string, edit-values )
  Edits (alters) a string of characters according to a list of
  edit values: COMPRESS, COLLAPSE, TRIM, UPCASE, LOWERCASE, UNCOMMENT.

F$ELEMENT( elem-number, delim-char, string )
  Extracts an element (character-delimited or -separated substring)
  from a string of characters.

F$EXTRACT( start-pos, length, string )
  Extracts a substring by start-position and length from a string.

F$FAO( control-string, arg [ , arg ...] )
  "Formatted ASCII Output", provides advanced output string formatting
  (comparable to the C-lib sprintf function).

F$LENGTH( string )
  Returns the length (as an integer) of a string of characters.

F$LOCATE( substring, string )
  Returns the position (as an integer) of a substring within a character
  string, or the length of the string if substring not found.

F$PARSE( filespec [ , default-spec ] [ , related-spec ]
         [ , field ] [ , parse-type ] )
  Parses a file specification, returning either the expanded full file
  specification or a particular filespec component requested.  Uses
  the RMS $PARSE system service.

F$STRING( arg )
  Converts its argument to a string of characters, if possible.
  The argument can be integer value or an integer expression.

F$CVSI( start-bit-offset, size-in-bits, string )
  Extracts bit fields from character string data and converts
  the result to an integer as a signed value.

F$CVUI( start-bit-offset, size-in-bits, string  )
  Extracts bit fields from character string data and converts
  the result to an integer as an unsigned value.

F$TIME()
  Takes no argument; returns the current system date and time as a string.

F$CVTIME( input-time [ , output-time-format ] [ , output-field ] )
  Reformats datetime strings into absolute, delta or combination
  formats, and retrieves field-information from a datetime value.

F$DELTA_TIME( start-time, end-time, format )
  Returns the time difference (an interval) between a given start
  time and an end time.

F$GETJPI( pid, item )
  Returns a specified item of information about the current process
  including identification, status and accounting information; with
  privilege, can return same information for another process on the
  system.  Uses the system service $GETJPI.

F$DIRECTORY()
  Takes no argument; returns the current default directory name (string)
  for the process.

F$ENVIRONMENT( item )
  Returns information about the current process's DCL command environment.

F$IDENTIFIER( identifier, conversion-type )
  Converts a rights-list identifier in named format to its integer equivalent,
  or vice versa.

F$MESSAGE( status-code [ , message-component-list ] )
  Returns the message text associated with a specified system status code value.

F$MODE()
  Takes no argument; returns the process's execution mode, one of:
  "INTERACTIVE", "BATCH", "NETWORK" or "OTHER".

F$PRIVILEGE( priv-list )
  Returns a TRUE if the current process privileges match (include) the privileges
  listed in the argument; returns FALSE otherwise.

F$PROCESS()
  Takes no argument; returns the current process name string.

F$SETPRV( priv-list )
  Sets (enables) the specified privileges in the current process, and returns
  a list of keywords indicating the previous state of the privileges.

F$TRNLNM( logical-name [ , table ] [ , index ] [ , mode ] [ , case ] [ , item ] )
  Translates a logical name and returns the equivalence name string and/or the
  requested attributes of the logical name.

F$USER()
  Takes no argument; returns the current process's user identification code (UIC).

F$SEARCH( filespec [ , stream-id ] )
  Searches for a specified file, returning the full file specification
  if the file exists, or an empty string "" otherwise.  Can search for
  files based on wildcards and through multiple directories and levels.

F$FILE_ATTRIBUTES( filespec, item )
  Returns file attribute (metadata) information for a specified file.

F$MATCH_WILD( candidate, pattern )
  Performs a wildcard matching between a candidate and a pattern string.

F$CUNITS( integer, [, from-units, to-units ] )
  Converts a number from one specified unit of measure
  to another (e.g., "BLOCKS" to "BYTES", and visa versa)

F$UNIQUE()
  Takes no argument; generates a string that is suitable to be a file name
  and is guaranteed to be unique across the cluster.

F$FID_TO_NAME( dev-name, file-id )
  Alpha/Integrity only.  Returns the full file specification of the
  file corresponding to a unique file identification (FID).

F$READLINK( filespec )
  Returns the target file name which is indicated (linked to) by the
  specified symbolic link, or an empty string "" if the input is not
  a symbolic link.

F$SYMLINK_ATTRIBUTES( filespec, item )
  Returns attribute information for a specified symbolic link file.
  Note that F$SYMLINK_ATTRIBUTES returns information for a specified
  symbolic link file, and not the target of the symbolic link. For
  information about the link's target file, use F$FILE_ATTRIBUTES.

F$GETENV( env-var-name )
  Alpha only.  Returns values of specified Alpha console
  environment variables.

F$GETDVI( dev-name, item [ , path-name ] )
  Returns a specified item of information about a specific device
  (disk, tape, terminal, network device, etc.).  Uses the system
  service $GETDVI.

F$DEVICE( [ search-devname ] [ , dev-class ] [ , dev-type ] [ , stream-id ] )
  Returns the device names of all devices (disks, tapes, terminals,
  network devices, etc.) that match the selection criteria.

F$MULTIPATH( dev-name, item, ctxt-symbol )
  Alpha/Integrity only.  Returns specific item of information about
  a specific multipath-capable device.

F$GETSYI( item [ , node-name ] [ , cluster-id ] )
  Returns a specified item of information about the local system
  environment, or about a node (system) in the local VMScluster.
  Uses the system service $GETSYI.

F$GETQUI( function [ , item ] [ , object-id ] [ , flags ] )
  Returns a specified item of information about queues, batch
  or print jobs currently queued, forms and characteristics
  definitions for queues.  Uses the system service $GETQUI.

F$LICENSE( license-name [ , producer-name ] )
  Alpha/Integrity only.  Checks whether the specified license is
  loaded on the system.

F$PID( ctxt-symbol )
  For each invocation, returns the next process identification number
  in sequence.  See F$CONTEXT below.

F$CONTEXT( ctxt-type, ctxt-symbol, sel-item, sel-value, value-qual )

  Specifies process selection criteria for use with F$PID (see above).

F$CSID( ctxt-symbol )
  Returns an OpenVMS Cluster identification number and
  updates the context symbol to point to the current
  position in the systems cluster node list.

F$TYPE( symbol-name )
  Returns the type of data of a specified DCL symbol, one of:
  "STRING", "INTEGER", or "" if the symbol is undefined.

F$VERIFY( [ procedure-value ] [ , image-value ] )
  Returns the integer 1 (TRUE) if command procedure verification is set on;
  returns the integer 0 (FALSE) if command procedure verification is set off.
  Also sets or toggles a new verification state based on its argument.

For examples of other DCL Lexical Functions in use, see:

• String Substitution Examples for two uses of F$GETDVI.

• But My Script Needs More Than 8 Parameters for use of F$ELEMENT and F$EDIT.

• Demonstrating Command Procedure Depth for an example of using F$ENVIRONMENT(“DEPTH”).