commit 128b4f1b6e6d0558b9da2f4f88b704f700dded86
parent d3418d81d555329ccd38dcab2150402948efd15e
Author: leitner <leitner>
Date: Fri, 31 May 2013 16:47:06 +0000
better man pages
Diffstat:
| M | minit.8 | | | 90 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------- |
| M | serdo.8 | | | 27 | ++++++++++++++++++++++----- |
2 files changed, 105 insertions(+), 12 deletions(-)
diff --git a/minit.8 b/minit.8
@@ -21,13 +21,89 @@ option in \fI/etc/lilo.conf\fR,
.I grub
users can just append it to their "\fIkernel\fR image options" lines.
+Or, of course, you can just call the binary /sbin/init, which is the
+default name the kernel starts when no kernel options are given.
+
.SH USAGE
-minit will by default do nothing except starting the minit service defined
-in
-.I /etc/minit/default
-which usually contains a file named
-.I depends
-specifying which services are to be started at bootup.
+minit will by default start the minit service called "default". If
+command line arguments are present, those are started instead of
+"default".
+
+It is possible to blacklist a service that is normally started by
+passing its name with a - in front of it. Example: default depends on
+init, init depends on loadgfxdriver, loadgfxdriver hangs the kernel in
+your kernel version so you want to boot without running it. Then you
+could use grub to pass the additional kernel arguments "default
+-loadgfxdriver" to minit. Minit would then run default and all its
+dependencies except loadgfxdriver.
+
+If the last service exits, minit will terminate.
+
+In case of catastrophic failure (for example if /etc/minit does not
+exist), minit will attempt to execute /sbin/sulogin. A careful admin
+will put some kind of emergency login command and shell there to provide
+a way to hopefully be able to recover from partially corrupted boot
+media or botched minit installations.
+
+.SH SERVICES
+minit services are defined in /etc/minit/[servicename]/ . When a service
+is started, minit changes into that directory, and reads the text file
+"depends". Every line in that file is interpreted as the name of a
+service and launched recursively like this. Finally, the file "run" is
+executed. This is usually a symbolic link to a binary.
+
+If the file "params" exists, each line is passed as a command line
+argument to the service binary. There is currently no way to pass
+command line arguments containing newline characters using this
+mechanism. You would have to make run a shell script to do that.
+
+All services are launched asynchronously, unless the service directory
+contains a file called "sync". If that file exists, minit blocks until
+the service finishes. This is meant for things that need to be
+completed before anything else can occur in the boot process, for
+example mounting /usr or /proc. Warning: minit will block when
+executing sync services, potentially leading to a deadlocked system.
+minit will also not respond to msvc while waiting for a sync service to
+commence.
+
+If a subdirectory called "log" exists, it is interpreted as a minit
+service, too, and its standard input is connected via a pipe to the
+standard output of the service. This is meant to be used with tools
+like multilog from the daemontools, see http://cr.yp.to/daemontools.html
+
+It is possible to provide data on stdin to a process by putting it into
+a file (or fifo) called "in" in the service directory. Likewise, if a
+file or fifo called "out" exists, stdout and stderr of the service will
+be redirected there.
+
+If a file called "nice" exists, its contents is interpreted as an
+integer and passed as argument to nice(2).
+
+If run is a symbolic link, minit will adjust argv[0] to the name
+part of it so programs like ps(1) and top(1) display the right name
+instead of "run".
+
+If a file called "respawn" exists, minit will restart the service should
+it ever exit. The default is not to respawn, because in typical
+scenarios most minit services are actually boot time housekeeping and
+initialization processes and not actual services that are expected to
+run for prolonged periods of time.
+
+.SH "CONVERTING A DAEMON INTO A SERVICE"
+
+The concept of minit works around long running service processes that do
+not terminate. If they do terminate, it is because of some unexpected
+failure or programming mistake and minit is expected to restart them.
+
+Unfortunately, most unix services are written as daemons. When run from
+a shell, they fork into the background and return immediately. In order
+for minit to be able to detect when those services abort, and to restart
+them if needed, minit needs to know the PID the service is running
+under.
+
+Most services have some way of turning off forking into the background.
+However, if the particular service does not have a way, pidfilehack can
+often be used.
.SH AUTHOR
minit was written by Felix von Leitner and can be downloaded from
@@ -38,4 +114,4 @@ This manpage was written by Erich Schubert <[email protected]>
for the Debian GNU/Linux operating system.
.SH "SEE ALSO"
-msvc(8), pidfilehack(8)
+msvc(8), serdo(8), pidfilehack(8)
diff --git a/serdo.8 b/serdo.8
@@ -14,16 +14,33 @@ is aborted (unless -c is given as first paramter on the serdo command
line).
serdo understands the \fBcd\fR, \fBexport\fR and \fBulimit\fR (set mode
-only) sh(1) built-ins (no loops, no ~user expansion, no $FOO expansion,
-no backticks).
+only) sh(1) built-ins (no loops, no globbiung, no ~user expansion, no
+$FOO expansion, no backticks).
serdo is very limited by design, but it is nice to have if you just want
to run a few ifconfig, ip, route commands in sequence. serdo will
return the exit code of the last command it ran, 0 if none were given.
-If no file name is given, but a file called "script" exists in the
-current working directory, serdo will execute that file. This saves a
-few inodes in a typical /etc/minit tree.
+If no file name is given as command line argument, but a file called
+"script" exists in the current working directory, serdo will execute
+that file. This saves a few inodes in a typical /etc/minit tree.
+
+.SH SYNTAX
+
+.B serdo scripts are Unix style text files with a list of commands, one
+per line. Usual shell script rules do not apply. No if, while,
+semicolons, no & to background jobs.
+
+Special commands that serdo does understand are cd, export, and ulimit.
+Spaces at the beginning of each line are ignored. If a line starts with
+a '#', it is considered a comment and ignored. Command line arguments
+that contain spaces can be grouped using single or double quotes.
+Characters can be escaped by putting a backslash ('\\') before them.
+
+Usually script execution is aborted if any command has a non-zero return
+value. This can be overridden by putting a '-' character in front of
+a command in the script file (or globally by passing the -c command line
+argument to serdo).
.SH AUTHOR
minit was written by Felix von Leitner and can be downloaded from
