4.0;if, revision 5.0, 82/10/07
IF -- Execute a conditional statement.
usage:  IF condition THEN command_1 [ELSE command_2...] ENDIF


FORMAT

  IF condition THEN command_1 ... [ELSE command_2 ...] ENDIF


  IF  executes  a  conditional  statement  depending on the results of a Boolean
  test.  You can extend the  IF  command  over  several  lines  if  you  use  it
  interactively or in a Shell script.  When you use IF interactively, and extend
  the command over more than one line, the Shell prompts you for each  new  line
  of the command with the $_ prompt (refer to the example below).


ARGUMENTS

  condition
  (required)         Specify a command or program to execute and test for truth,
                     or specify a variable expression  or  Boolean  variable  to
                     test  for  truth.    "Truth" usually means that the command
                     executes successfully (without any  errors),  or  that  the
                     Shell   variable   expression   or   Boolean   is   "true".
                     (Specifically,  this  argument  is  evaluated  TRUE  if  it
                     returns an abort severity level of 0 (zero).)

                     Refer   to   the   DOMAIN  System  User's  Guide  for  more
                     information on Shell variables.

  command_1
  (required)         Specify  command  or  program  to  execute  if  'condition'
                     returns TRUE.

  command_2
  (optional)          Specify  command  or  program  to  execute  if 'condition'
                     returns FALSE (i.e., a severity level greater than zero).


EXAMPLES

    1. $ IF eqs a a
       $_ THEN args "a is a"
       $_ ELSE args "Aristotle was wrong."
       $_ ENDIF
       a is a
       $

    2. IF eqs ^2 '-c'
       THEN pas ^1
            bind ^1.bin library -b ^1
       ELSE bind ^1.bin library -b ^1
       ENDIF

  Example 2 might appear in a Shell script.  These lines will compile the Pascal
  module  named  by the first argument (^1) if the second argument (^2) is '-c'.
  Then it will bind the module with 'library'.  If the second  argument  is  not
  '-c', or if there is no second argument, the command simply binds the module.


RELATED TOPICS

  More information is available.  Type:

  - HELP ABTSEV
   for information about abort severity levels.