* pathnames.sgml: Add documentation about raw block special

devices and tape devices to the "POSIX devices" chapter.
This commit is contained in:
Corinna Vinschen 2000-09-29 21:53:52 +00:00
parent 684ee6cce2
commit 795f46d9db
2 changed files with 58 additions and 7 deletions

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@ -1,3 +1,8 @@
Fri Sep 29 23:52:00 2000 Corinna Vinschen <corinna@vinschen.de>
* pathnames.sgml: Add documentation about raw block special
devices and tape devices to the "POSIX devices" chapter.
Fri Aug 18 15:51:06 2000 Christopher Faylor <cgf@cygnus.com>
* fhandler-tut.txt: hinfo -> dtable.

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@ -126,7 +126,7 @@ two (see <Xref Linkend="cygpath">) can be eliminated:</para>
<example><title>Identity mount setup</title>
<screen>
<prompt>C:\&gt;</prompt> <userinput>mount c:\ \</userinput>
<prompt>C:\&gt;</prompt> <userinput>mount c:\ /</userinput>
<prompt>C:\&gt;</prompt> <userinput>mount d:\foo /foo</userinput>
<prompt>C:\&gt;</prompt> <userinput>mount d:\bar /bar</userinput>
<prompt>C:\&gt;</prompt> <userinput>mount e:\grill /grill</userinput>
@ -192,14 +192,60 @@ default printer with the command <command>cat filename > PRN</command>
<para>There is no need to create a POSIX <filename>/dev</filename>
directory as it is simulated within Cygwin automatically.
It supports the following devices: <filename>/dev/null</filename>,
<filename>/dev/tty</filename> and
<filename>/dev/comX</filename> (the serial ports).
<filename>/dev/zero</filename>, <filename>/dev/tty</filename>,
<filename>/dev/ttyX</filename>, <filename>/dev/ptmx</filename>,
<filename>/dev/comX</filename> (the serial ports),
<filename>/dev/windows</filename> (the windows message queue),
<filename>/dev/random</filename> and <filename>/dev/urandom</filename>.
These devices cannot be seen with the command <command>ls /dev</command>
although commands such as <command>ls /dev/tty</command> work fine.
<comment>
FIXME: Are there other devices under /dev. What about the funny ones
mounted by default, such as /dev/fd1. What do they really do?
</comment>
</para>
<para>However, on Windows NT/W2K there are different devices which are
supported but have to be created as mount points. These are the raw block
special devices and tape devices. These devices need a special handling
which is enabled through the mount points. The usage of the native Windows
device names is not sufficent.
</para>
<para>NT/W2K supports raw block special device support for partitions
and drives. The device names for partitions is the drive letter
with leading <filename>\\.\</filename>, so the floppy would be
<filename>\\.\A:</filename>, the first partition typically
<filename>\\.\C:</filename>. Complete drives (except floppies
which are supported as partitions only) are named
<filename>\\.\PHYSICALDRIVEx</filename>. The <literal>x</literal>
is the drive number which you can check in the disk manager.
Each drive line has prepended the text "Disk x".
</para>
<para>To access tape drives, NT/W2K uses the file name
<filename>\\.\TAPEx</filename>. For example the first installed tape device
is named <filename>\\.\tape0</filename>.
</para>
<para>To access those devices you have to mount them and you have to
use the posix name of the device to be recognized by Cygwin.
The naming convention is simple: The name has to begin with
<filename>/dev/</filename> and the rest is as you like. The only
exception are tape devices. To identify if the tape device is
used as rewind or no-rewind device the name must not begin with
<literal>n</literal> (rewind) or has to begin with <literal>n</literal>
(no-rewind).
</para>
<para>Some examples:</para>
<screen>
mount -b //./A: /dev/fd0 # mount floppy as raw block special
mount -b //./physicaldrive1 /dev/hdb # mount "Disk 1"
mount -b //./tape0 /dev/st0 # mount first tape as the rewind device...
mount -b //./tape0 /dev/nst0 # ...and as the no-rewind device
</screen>
<para>Note the usage of the <literal>-b</literal> option. It is best to
include the -b option when mounting these devices to ensure that all
file I/O is in "binary mode".
</para>
</sect2>