Executes a command procedure or requests the command interpreter  to
  read subsequent command input from a specific file or device.

  Format:


    @ file-spec [p1 [p2 [...  p8]]]

Additional information available:

ParametersCommand QualifiersExamples

 file-spec

  Specifies either the command procedure to be executed or the  device
  or file from which input for the preceding command is to be read.

  If you do not specify a file type, the system uses the default  file
  type of COM.

  No wildcard characters are allowed in the file specification.

 p1 [p2 [...  p8]]

  Specifies from one to eight  optional  parameters  to  pass  to  the
  command procedure.  The parameters assign character string values to
  the symbols named P1, P2, and so on in the  order  of  entry,  to  a
  maximum  of  eight.   The symbols are local to the specified command
  procedure.

  Separate each parameter with one  or  more  blanks.   Use  quotation
  marks ("") to specify a null parameter.  You can specify a parameter
  with a character string value  containing  alphanumeric  or  special
  characters, with the following restrictions:

  o  The  command  interpreter  converts  alphabetic   characters   to
     uppercase  and  uses blanks to delimit each parameter.  To pass a
     parameter that contains  embedded  blanks  or  literal  lowercase
     letters, place the parameter in quotation marks.

  o  If the first parameter begins with a  slash  character  (/),  you
     must enclose the parameter in quotation marks.

  o  To pass a parameter that contains  literal  quotation  marks  and
     spaces,  enclose  the  entire string in quotation marks and use a
     double set of quotation marks within the string.  For example:

          $ @TEST "Never say ""quit"""

     When the procedure TEST.COM executes, the parameter P1 is equated
     to the string:

          Never say "quit"

     If a string contains quotation marks and does not contain spaces,
     the  quotation  marks are preserved in the string and the letters
     within the quotation marks remain in lowercase.  For example:

          $ @ANOTHER_TEST abc"def"ghi

     When the procedure ANOTHER_TEST.COM executes, the parameter P1 is
     equated to the string:

          ABC"def"GHI

  To use a symbol as a parameter, enclose the symbol in apostrophes to
  force symbol substitution.  For example:

       $ NAME = "JOHNSON"
       $ @INFO 'NAME'

  The apostrophes cause the value "JOHNSON" to be substituted for  the
  symbol  NAME.  Therefore, the parameter "JOHNSON" is passed as P1 to
  INFO.COM.

Additional information available:

/OUTPUT

 /OUTPUT=file-spec

 Requests that all output directed to the logical device SYS$OUTPUT be
  written to the file or device specified.  System responses and error
  messages are written to SYS$COMMAND as  well  as  to  the  specified
  file.

  If you specify /OUTPUT, the qualifier must  immediately  follow  the
  file   specification   of  the  command  procedure;  otherwise,  the
  qualifier is interpreted as a  parameter  to  pass  to  the  command
  procedure.

  The default output file type is LIS.

  No wildcard characters are allowed in the output file specification.

  You can also redefine SYS$OUTPUT  to  redirect  the  output  from  a
  command procedure.  If you place the command:

       $ DEFINE SYS$OUTPUT file-spec

  as the first line in a command procedure, output will be directed to
  the  file you specify.  When the procedure exits, SYS$OUTPUT will be
  restored to its original equivalence string.  This produces the same
  result  as  using the /OUTPUT qualifier when you execute the command
  procedure.

  1.   $ CREATE DOFOR.COM
       $ ON WARNING THEN EXIT
       $ IF P1.EQS."" THEN INQUIRE P1 FILE
       $ FORTRAN/LIST 'P1'
       $ LINK 'P1'
       $ RUN 'P1'
       $ PRINT 'P1'
       <CTRL/Z>
       $ @DOFOR AVERAGE

  This example  shows  a  command  procedure,  named  DOFOR.COM,  that
  executes  the  FORTRAN, LINK, and RUN commands to compile, link, and
  execute a program.  The ON command requests that the  procedure  not
  continue if any of the commands result in warnings or errors.

  When you execute DOFOR.COM, you can pass the file  specification  of
  the  FORTRAN  program  as the parameter P1.  If you do not specify a
  value for P1 when you execute the  procedure,  the  INQUIRE  command
  issues  a  prompting  message  to  the terminal and equates what you
  enter with the symbol P1.  In this example, the file name AVERAGE is
  assigned  to P1.  The file type is not included because the commands
  FORTRAN, LINK, RUN, and PRINT provide default file types.

  2. $ @MASTER/OUTPUT=MASTER.LOG

  This command executes a procedure named MASTER.COM;  all  output  is
  written to the file MASTER.LOG.

  3. $ CREATE QUALIFIERS.COM
       /DEBUG/SYMBOL_TABLE/MAP/FULL/CROSS_REFERENCE
       <CTRL/Z>
       $ LINK SYNAPSE@QUALIFIERS

  This  example  shows  a  command  procedure,  QUALIFIERS.COM,   that
  contains  qualifiers  for the LINK command.  When you issue the LINK
  command, specify the command procedure immediately  after  the  file
  specification  of  the  file  you  are linking.  Do not type a space
  between the file specification and the @ command.