VC(1) DOMAIN/IX Reference Manual (SYS5) VC(1)
NAME
vc - version control
USAGE
vc [ -a ] [ -t ] [ -cchar ] [ -s ] [ keyword=value ...
keyword=value ]
DESCRIPTION
Vc copies lines from the standard input to the standard out-
put under control of its arguments and control statements
encountered in the standard input. In the process of per-
forming 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 state-
ments) of keyword values specified in control statements or
as vc command arguments.
A control statement is a single line beginning with a con-
trol character, except as modified by the -t option (see
below). The default control character is a colon (:),
except as modified by the -c option (see below). Input
lines beginning with a backslash (\) and followed by a con-
trol character are not control lines. These lines are
copied to the standard output with the backslash removed.
Lines beginning with a backslash and followed by a non-
control character are copied in their entirety.
A keyword is composed of nine or fewer 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.
Vc replaces keywords by values whenever it finds a keyword
surrounded by control characters on a version control state-
ment. The -a option (see below) forces replacement of key-
words in all lines of text. An uninterpreted control char-
acter may be included in a value by preceding it with a
backslash. If a literal \ is desired, then it too must be
preceded by a backslash.
OPTIONS
-a Force replacement of keywords surrounded by con-
trol characters with their assigned value in all
text lines and not just in vc statements.
-t Ignore all characters from the beginning of a line
up to and including the first tab character, for
the purpose of detecting a control statement. If
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one is found, discard all characters up to and
including the tab.
-cchar Specify a control character to be used in place of
a colon.
-s Silence warning messages (not error) that are nor-
mally printed on the diagnostic output.
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's for that keyword.
Keywords declared, but 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 match-
ing 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
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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 pre-
cedence.
Values must be separated from operators or parentheses
by at least one blank or tab.
::text
Replace keywords on lines copied to the standard out-
put. Remove the two leading control characters, and
replace keywords surrounded by control characters in
text by their value before copying the line to the out-
put file. This action is independent of the -a option.
:on
:off
Turn on or turn off keyword replacement on all lines.
:ctl char
Change the control character to char.
:msg message
Print the given message on the diagnostic output.
:err message
Print the given message followed by:
ERROR: err statement on line ... (915)
on the diagnostic output. Halt vc execution, and
return an exit code of 1.
EXIT CODES
0 - normal
1 - any error
DIAGNOSTICS
Use help (1) for explanations.
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RELATED INFORMATION
ed (1), help (1).
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