vc(1) vc(1)
NAME
vc - version control
SYNOPSIS
vc [option...] [keyword=value...]
DESCRIPTION
vc (version control) is obsolete and will be removed in the next
release.
The vc command copies lines from the standard input to the standard
output under control of its arguments and of 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 of keyword values specified in control
statements or as vc command arguments.
A control statement is a single line beginning with a control charac-
ter. The exception to this is -t. The default control character is a
colon :, but this can be modified using the -c keyletter. 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; a
numeric value is an unsigned string of digits. Keyword values may not
contain blanks or tabs.
Keywords are replaced by values whenever a keyword enclosed between
control characters is encountered in a control statement. The -a
keyletter forces replacement of keywords throughout the text. An unin-
terpreted 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
-a Replaces keywords enclosed between 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 detecting
a control statement. If a control statement is found, all char-
acters up to and including the tab are discarded.
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vc(1) vc(1)
-cchar
Specifies a control character to be used in place of the :
default.
-s Silences warning messages that are normally printed on the diag-
nostic output; but not error messages.
vc recognizes the following version control statements:
:dcl keyword[, ..., keyword]
Declare keywords. All keywords must be declared.
:asg keyword=value
Assign values to keywords. An asg statement overrides the
assignment for the corresponding keyword on the vc command line
and all previous asg statements for that keyword. Keywords that
are declared but are not assigned values have null values.
:if condition
...
:end 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 state-
ments. 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> ::= <expr> | <expr> '&' <and>
<expr> ::= '(' <or> ')' | <value>
<op> <value>
<op> ::= '=' | '!=' | '<' | '>'
<value> ::= <arbitrary ASCII string> | <numeric string>
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vc(1) vc(1)
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 an if and, when present,
inverts the value of the entire condition
The comparisons > 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 is as follows:
= != > < 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
Replace keywords on lines that are copied to the standard out-
put. The two leading control characters are removed, and key-
words 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 Turn on keyword replacement on all lines.
:off Turn off keyword replacement on all lines.
:ctl char
Change the control character to char.
:msg message
Prints the specified message on the error output.
:err message
Prints the specified message on the error output:
ERROR: err statement on line ... (915)
vc halts execution, and returns an exit status of 1.
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vc(1) vc(1)
SEE ALSO
ed(1), help(1).
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