vc(1)							      General Commands Manual							     vc(1)

Name
       vc - version control program

Syntax
       vc [-a] [-t] [-cchar] [-s] [keyword=value... keyword=value]

Description
       The  command  copies lines from the standard input to the standard output under control of its arguments and control statements encountered
       in the standard input.  In the process of performing the copy operation, user declared keywords may be replaced by their string value  when
       they appear in plain text and/or control statements.

       The  copying  of  lines from the standard input to standard output is conditional.  It is based on tests (in control statements) of keyword
       values specified in control statements or as command arguments.

       A control statement is a single line beginning with a control character, except as modified by the -t keyletter (see below).   The  default
       control character is colon (:), except as modified by the -c keyletter (see below).  Input lines beginning with a backslash () followed by
       a control character are not control lines and are copied to the standard output with the backslash removed.  Lines beginning with  a  back-
       slash followed by a noncontrol character are copied in their entirety.

       A  keyword  is  composed of 9 or fewer alphanumerics; the first must be alphabetic.  A value is any ASCII string that can be created with A
       numeric value is an unsigned string of digits.  Keyword values should contain blanks or tabs.

       Replacement of keywords by values occurs whenever a keyword surrounded by control characters is encountered on a version control statement.
       The  -a keyletter (see below) forces replacement of keywords in all lines of text.  An uninterpreted control character may be included in a
       value by preceding it with .  If a literal  is desired, then it too must be preceded by .

Options
       Keyletter arguments:

       -a Replaces the keywords surrounded by control characters in all text lines.

       -cchar
	  Specifies a control character to be used in place of :.

       -s Suppresses all warning messages.

       -t Ignores all characters from the beginning of the line to the first tab character.  If one is found, all characters up to  and  including
	  the tab are discarded.

Version Control Statements:
       :dcl  keyword[, ..., keyword]
	    Used to declare keywords.  All keywords must be declared.

       :asg keyword=value
	    Used  to  assign  values to keywords.  An asg statement overrides the assignment for the corresponding keyword on the command line and
	    all previous asg's for that keyword.  Keywords declared, but not assigned values have null values.

       :if condition
	    .
	    .
	    .
       :end
	    Used to skip lines of the standard input. If the condition is true all lines between the if statement and the matching  end  statement
	    are  copied  to  the  standard  output.  If the condition is false, all intervening lines are discarded, including control statements.
	    Note that intervening if statements and matching end statements are recognized solely for the purpose of maintaining the proper if-end
	    matching.
	    The syntax of a condition is:

	     <cond>  ::= [ "not" ] <or>
	     <or>    ::= <and> | <and> "|" <or>
	     <and>   ::= <exp> | <exp> "&" <and>
	     <exp>   ::= "(" <or> ")" | <value> <op> <value>
	     <op>    ::= "=" | "!=" | "<" | ">"
	     <value> ::= <arbitrary ASCII string> | <numeric string>

	    The available operators and their meanings are:

	       =      equal
	       !=     not equal
	       &      and
	       |      or
	       >      greater than
	       <      less than
	       ( )    used for logical groupings
	       not    may only occur immediately after the if, and
		      when present, inverts the value of the
		      entire condition

	    The  >  and  < operate only on unsigned integer values.  For example, : 012 > 12 is false).  All other operators take strings as argu-
	    ments.  For example, fB: 012 != 12 is true).  The precedence of the operators (from highest to lowest) is:
	       = != > <      all of equal precedence
	       &
	       |
	    Parentheses can be used to alter the order of precedence.
	    Values must be separated from operators or parentheses by at least one blank or tab.

       ::text
	    Used for keyword replacement on lines that are copied to the standard output.  The two leading control  characters	are  removed,  and
	    keywords  surrounded  by  control  characters  in text are replaced by their value before the line is copied to the output file.  This
	    action is independent of the -a keyletter.

       :on

       :off
	    Turn on or off keyword replacement on all lines.

       :ctl char
	    Change the control character to char.

       :msg message
	    Prints the given message on the diagnostic output.

       :err message
	    Prints the given message followed by:
		 ERROR: err statement on line ... (915)
	    on the diagnostic output.  The command halts execution, and returns an exit code of 1.

Diagnostics
       Use for explanations.

Exit Codes
       0 - normal
       1 - any error

																	     vc(1)