


      VC(1)                       (UNIX 5.0)                      VC(1)



      NAME
           vc - version control

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

      DESCRIPTION
           The vc 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 the standard
           output is conditional, based on tests (in control
           statements) of keyword values specified in control
           statements or as vc 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 backslash followed by a non-control character are
           copied in their entirety.

           A keyword is composed of 9 or less alphanumerics; the first
           must be alphabetic.  A value is any ASCII string that can be
           created with ed(1); a numeric value is an unsigned string of
           digits.  Keyword values may not contain blanks or tabs.

           Replacement of keywords by values is done 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 \.

           Keyletter arguments

                -a             Forces replacement of keywords
                               surrounded by control characters with
                               their assigned value in all text lines
                               and not just in vc statements.

                -t             All characters from the beginning of a
                               line up to and including the first tab
                               character are ignored for the purpose of



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      VC(1)                       (UNIX 5.0)                      VC(1)



                               detecting a control statement.  If one
                               is found, all characters up to and
                               including the tab are discarded.

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

                -s             Silences warning messages (not error)
                               that are normally printed on the
                               diagnostic output.

           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 vc command line and all previous asg's for that
                keyword.  Keywords declared, but not assigned values
                have null values.
                :if condition
8                     .
8                     .
8                     .
                :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


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      VC(1)                       (UNIX 5.0)                      VC(1)



                   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 (e.
                g.: 012 > 12 is false).  All other operators take
                strings as arguments (e. g.: 012 != 12 is true).  The
                precedence of the operators (from highest to lowest)
                is:
                   = != > <      all of equal precedence
                   &
                   |
                Parentheses may 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.  Vc halts execution, and
                returns an exit code of 1.

      DIAGNOSTICS
           Use help(1) for explanations.

      EXIT CODES
           0 - normal
           1 - any error







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