rcorder
—
print a dependency ordering of interdependent
files
rcorder |
[ -k
keep ]
[-s
skip ]
file ... |
The
rcorder
utility is designed to print out
a dependency ordering of a set of interdependent files. Typically it is used
to find an execution sequence for a set of shell scripts in which certain
files must be executed before others.
Each file passed to
rcorder
must be annotated
with special lines (which look like comments to the shell) which indicate the
dependencies the files have upon certain points in the sequence, known as
“conditions”, and which indicate, for each file, which
“conditions” may be expected to be filled by that file.
Within each file, a block containing a series of
“
REQUIRE
”,
“
PROVIDE
”,
“
BEFORE
” and
“
KEYWORD
” lines must appear. The format
of the lines is rigid. Each line must begin with a single
‘
#
’, followed by a single space,
followed by “
PROVIDE:
”,
“
REQUIRE:
”,
“
BEFORE:
”, or
“
KEYWORD:
”. No deviation is permitted.
Each dependency line is then followed by a series of conditions, separated by
whitespace. Multiple “
PROVIDE
”,
“
REQUIRE
”,
“
BEFORE
” and
“
KEYWORD
” lines may appear, but all such
lines must appear in a sequence without any intervening lines, as once a line
that does not follow the format is reached, parsing stops.
The options are as follows:
-k
- Add the specified keyword to the “keep list”. If any
-k
option is given, only those files
containing the matching keyword are listed.
-s
- Add the specified keyword to the “skip list”. If any
-s
option is given, files containing
the matching keyword are not listed.
An example block follows:
# REQUIRE: networking syslog
# REQUIRE: usr
# PROVIDE: dns nscd
This block states that the file in which it appears depends upon the
“
networking
”,
“
syslog
”, and
“
usr
” conditions, and provides the
“
dns
” and
“
nscd
” conditions.
A file may contain zero “
PROVIDE
” lines,
in which case it provides no conditions, and may contain zero
“
REQUIRE
” lines, in which case it has no
dependencies. There must be at least one file with no dependencies in the set
of arguments passed to
rcorder
in order for
it to find a starting place in the dependency ordering.
The
rcorder
utility may print one of the
following error messages and exit with a non-zero status if it encounters an
error while processing the file list.
- Requirement %s has no providers, aborting.
- No file has a “
PROVIDE
” line
corresponding to a condition present in a
“REQUIRE
” line in another file.
- Circular dependency on provision %s, aborting.
- A set of files has a circular dependency which was detected while
processing the stated condition.
- Circular dependency on file %s, aborting.
- A set of files has a circular dependency which was detected while
processing the stated file.
rc(8)
The
rcorder
utility appeared in
NetBSD 1.5.
rcorder
utility first appeared in
FreeBSD 5.0.
Written by
Perry E. Metzger
<
perry@piermont.com>
and
Matthew R. Green
<
mrg@eterna.com.au>.
The “
REQUIRE
” keyword is misleading: It
does not describe which daemons have to be running before a script will be
started. It describes which scripts must be placed before it in the dependency
ordering. For example, if your script has a
“
REQUIRE
” on
“
named
”, it means the script must be
placed after the “
named
” script in the
dependency ordering, not necessarily that it requires
named(8)
to be started or enabled.