NAME
rcorder
—
print a dependency ordering of
interdependent files
SYNOPSIS
rcorder |
[-gp ] [-k
keep] [-s
skip] file ... |
DESCRIPTION
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:
-g
- Produce a GraphViz (.dot) of the complete dependency graph instead of plaintext calling order list.
-k
keep- Add the specified keyword to the “keep list”. If any
-k
option is given, only those files containing the matching keyword are listed. This option can be specified multiple times. -p
- Generate ordering suitable for parallel startup, placing files that can be executed simultaneously on the same line.
-s
skip- Add the specified keyword to the “skip list”. If any
-s
option is given, files containing the matching keyword are not listed. This option can be specified multiple times.
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.
KEYWORDS
There are several KEYWORDs in use:
- firstboot, nojail, nojailvnet, nostart
- Used by rc(8).
- resume
- Used by
/etc/rc.resume
(see acpiconf(8)) - shutdown
- Used by rc.shutdown(8).
EXAMPLES
Print the dependency ordering of the services from the base system and ports(7):
$ rcorder /etc/rc.d/* /usr/local/etc/rc.d/*
Count the number of services in the base system, which specify the shutdown keyword, while skipping those with firstboot and nojailvnet:
$ rcorder -k nostart -s firstboot -s nojailvnet /etc/rc.d/* | wc -l 3
DIAGNOSTICS
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 in file %s has no providers.
- No file has a ‘
PROVIDE
’ line corresponding to a condition present in a ‘REQUIRE
’ line in another file. - Circular dependency on provision %s in file %s.
- A set of files has a circular dependency which was detected while processing the stated condition. Loop visualization follows this message.
- Circular dependency on file %s.
- A set of files has a circular dependency which was detected while processing the stated file.
- %s was seen in circular dependencies for %d times.
- Each node that was a part of circular dependency loops reports total number of such encounters. Start with files having biggest counter when fighting with broken dependencies.
DIAGNOSTICS WITH GRAPHVIZ
Direct dependency is drawn with solid line,
‘BEFORE
’ dependency is drawn as a
dashed line. Each node of a graph represents an item from
‘PROVIDE
’ lines. In case there are
more than one file providing an item, a list of filenames shortened with
basename(3) is shown. Shortened filenames are also shown in case
‘PROVIDE
’ item does not match file
name.
Edges and nodes where circular dependencies were detected are
drawn bold red. If a file has an item in
‘REQUIRE
’ or in
‘BEFORE
’ that could not be provided,
this missing provider and the requirement will be drawn bold red as
well.
SEE ALSO
HISTORY
The rcorder
utility appeared in
NetBSD 1.5. rcorder
utility
first appeared in FreeBSD 5.0.
AUTHORS
Written by Perry E. Metzger <perry@piermont.com> and Matthew R. Green <mrg@eterna.com.au>.
BUGS
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
‘sshd
’, it means the script must be
placed after the ‘sshd
’ script in the
dependency ordering, not necessarily that it requires
sshd
to be started or enabled.