/sys$common/syshlp/helplib.hlb =, Examples  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    1.$ LIST == "DIRECTORY"

      The assignment statement in this example assigns the user-
      defined synonym LIST as a global symbol definition for the DCL
      command DIRECTORY.

    2.$ COUNT = 0
      $ LOOP:
      $      COUNT = COUNT + 1
      $      IF P'COUNT' .EQS. "" THEN EXIT
      $      APPEND/NEW &P'COUNT' SAVE.ALL
      $      DELETE &P'COUNT';*
      $      IF COUNT .LT. 8 THEN GOTO LOOP
      $ EXIT

      This command procedure, COPYDEL.COM, appends files (specified
      as parameters) to a file called SAVE.ALL. After a file has been
      appended, the command procedure deletes the file. Up to eight
      file names can be passed to the command procedure. The file
      names are assigned to the symbols P1, P2, and so on.

      The command procedure uses a counter to refer to parameters
      that are passed to it. Each time through the loop, the
      procedure uses an IF command to check whether the value of
      the current parameter is a null string. When the IF command is
      scanned, the current value of the symbol COUNT is concatenated
      with the letter P. The first time through the loop, the IF
      command tests P1; the second time through the loop it tests
      P2, and so on. After the expression P`COUNT' is evaluated, the
      substitution of the file names that correspond to P1, P2, and
      so on is automatic within the context of the IF command.

      The APPEND and DELETE commands do not perform any substitution
      automatically, because they expect and require file
      specifications as input parameters. The ampersand (&) precedes
      the P`COUNT' expression for these commands to force the
      appropriate symbol substitution. When these commands are
      initially scanned each time through the loop, COUNT is
      substituted with its current value. Then, when the commands
      execute, the ampersand causes another substitution: the first
      file specification is substituted for P1, the second file
      specification is substituted for P2, and so on.

      To invoke this procedure, use the following command:

        $ @COPYDEL ALAMO.TXT BEST.DOC

      The files ALAMO.TXT and BEST.DOC are each appended to the file
      SAVE.ALL and are then deleted.

    3.$ A = 25
      $ CODE = 4 + F$INTEGER("6") - A
      $ SHOW SYMBOL CODE
        CODE = -15   HEX = FFFFFFF1   Octal = 1777761

      This example contains two assignment statements. The first
      assignment statement assigns the value 25 to the symbol A. The
      second assignment statement evaluates an expression containing
      an integer (4), a lexical function (F$INTEGER("6")), and the
      symbol A. The result of the expression, -15, is assigned to the
      symbol CODE.

    4.$ FILENAME = "JOBSEARCH" - "JOB"
      $ FILETYPE = ".OBJ"
      $ FILESPEC = FILENAME + FILETYPE
      $ TYPE 'FILESPEC'

      The first command in this example assigns the symbol FILENAME
      the value "SEARCH". Notice that the string "SEARCH" is the
      result of the string reduction operation performed by the
      expression. The second command assigns the symbol FILETYPE
      the character string ".OBJ".

      The symbols FILENAME and FILETYPE are then added together in an
      expression assigned to the symbol FILESPEC. Because the values
      of the symbols FILENAME and FILETYPE are concatenated, the
      resultant value assigned to FILESPEC is the character string
      "SEARCH.OBJ". The symbol FILESPEC is then used as a parameter
      for the TYPE command. The single quotation marks (` ')  request
      the command interpreter to replace the symbol FILESPEC with its
      value SEARCH.OBJ. Thus, the TYPE command types the file named
      SEARCH.OBJ.

    5.$ BELL[0,32] = %X07
      $ SHOW SYMBOL BELL
        BELL = ""

      In this example, the symbol BELL is created with an arithmetic
      overlay assignment statement. Because the symbol BELL is
      previously undefined, the hexadecimal value 7 is inserted
      over a null character string and is interpreted as the ASCII
      code for the bell character on a terminal. When you issue the
      command SHOW SYMBOL BELL, the terminal beeps.

      If the symbol BELL had been previously defined with an integer
      value, the result of displaying BELL would have been to show
      its new integer value.

    6.$ $=34
      %DCL-W-NOCOMD, no command on line - reenter with alphabetic first
      character
      $ $$=34
      $ SHOW SYMBOL $$
      %DCL-W-UNDSYM, undefined symbol - check validity and spelling
      $ SHOW SYMBOL $
      $ = 34   Hex = 00000022  Octal = 00000000042

      If you begin a symbol name with the dollar sign ($),  use two
      dollar signs ($$)  because DCL discards the first instance of
      the dollar sign.