VC(1SCCS) COMMAND REFERENCE VC(1SCCS)
NAME
vc - version control
SYNOPSIS
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 noncontrol character are
copied in their entirety.
A keyword is composed of nine 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 \.
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
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VC(1SCCS) COMMAND REFERENCE VC(1SCCS)
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
.
.
.
: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 arguments (for example,: 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
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VC(1SCCS) COMMAND REFERENCE VC(1SCCS)
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 message on the diagnostic output.
:err message
Prints the message followed by:
ERROR: err statement on line ... (915)
on the diagnostic output. Vc halts execution, and returns
an exit code of 1.
OPTIONS
-a Forces replacement of keywords surrounded by control
characters with their assigned value in all text lines,
not just in vc statements.
-cchar
Specifies a control character to be used in place of the
: character.
-s Silences warning messages (not error) that are normally
printed on the diagnostic output.
-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 one is
found, all characters up to and including the tab are
discarded.
DIAGNOSTICS
Use sccshelp (1sccs) for explanations.
SEE ALSO
sccshelp(1sccs).
Printed 10/17/86 3
%%index%%
na:72,56;
sy:128,262;
de:390,2597;3131,2241;5516,944;
op:6460,788;
di:7248,149;
se:7397,102;
%%index%%000000000126