Generated code for mknod, mkfifo, mknod_b, mknod_c, umask.

[libguestfs.git] / guestfish-actions.pod

diff --git a/guestfish-actions.pod b/guestfish-actions.pod
index 74242e3..8ced2e1 100644 (file)
--- a/guestfish-actions.pod
+++ b/guestfish-actions.pod
@@ -6,6 +6,11 @@ This function adds a virtual CD-ROM disk image to the guest.
 
 This is equivalent to the qemu parameter C<-cdrom filename>.
 
 
 This is equivalent to the qemu parameter C<-cdrom filename>.
 

+Note that this call checks for the existence of C<filename>.  This
+stops you from specifying other types of drive which are supported
+by qemu such as C<nbd:> and C<http:> URLs.  To specify those, use
+the general C<config> call instead.
+

 =head2 add-drive | add
 
  add-drive filename
 =head2 add-drive | add
 
  add-drive filename


@@ -21,7 +26,33 @@ for whatever operations you want to perform (ie. read access if you
 just want to read the image or write access if you want to modify the
 image).
 
 just want to read the image or write access if you want to modify the
 image).
 

-This is equivalent to the qemu parameter C<-drive file=filename>.
+This is equivalent to the qemu parameter C<-drive file=filename,cache=off>.
+
+Note that this call checks for the existence of C<filename>.  This
+stops you from specifying other types of drive which are supported
+by qemu such as C<nbd:> and C<http:> URLs.  To specify those, use
+the general C<config> call instead.
+
+=head2 add-drive-ro | add-ro
+
+ add-drive-ro filename
+
+This adds a drive in snapshot mode, making it effectively
+read-only.
+
+Note that writes to the device are allowed, and will be seen for
+the duration of the guestfs handle, but they are written
+to a temporary file which is discarded as soon as the guestfs
+handle is closed.  We don't currently have any method to enable
+changes to be committed, although qemu can support this.
+
+This is equivalent to the qemu parameter
+C<-drive file=filename,snapshot=on>.
+
+Note that this call checks for the existence of C<filename>.  This
+stops you from specifying other types of drive which are supported
+by qemu such as C<nbd:> and C<http:> URLs.  To specify those, use
+the general C<config> call instead.

 
 =head2 aug-close
 
 
 =head2 aug-close
 


@@ -370,7 +401,16 @@ or compatible processor architecture).
 The single parameter is an argv-style list of arguments.
 The first element is the name of the program to run.
 Subsequent elements are parameters.  The list must be
 The single parameter is an argv-style list of arguments.
 The first element is the name of the program to run.
 Subsequent elements are parameters.  The list must be

-non-empty (ie. must contain a program name).
+non-empty (ie. must contain a program name).  Note that
+the command runs directly, and is I<not> invoked via
+the shell (see C<sh>).
+
+The return value is anything printed to I<stdout> by
+the command.
+
+If the command returns a non-zero exit status, then
+this function returns an error message.  The error message
+string is the content of I<stderr> from the command.

 
 The C<$PATH> environment variable will contain at least
 C</usr/bin> and C</bin>.  If you require a program from
 
 The C<$PATH> environment variable will contain at least
 C</usr/bin> and C</bin>.  If you require a program from


@@ -383,6 +423,10 @@ correct places.  It is the caller's responsibility to ensure
 all filesystems that are needed are mounted at the right
 locations.
 
 all filesystems that are needed are mounted at the right
 locations.
 

+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+

 =head2 command-lines
 
  command-lines 'arguments ...'
 =head2 command-lines
 
  command-lines 'arguments ...'


@@ -390,6 +434,12 @@ locations.
 This is the same as C<command>, but splits the
 result into a list of lines.
 
 This is the same as C<command>, but splits the
 result into a list of lines.
 

+See also: C<sh-lines>
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+

 =head2 config
 
  config qemuparam qemuvalue
 =head2 config
 
  config qemuparam qemuvalue


@@ -403,6 +453,20 @@ The first character of C<param> string must be a C<-> (dash).
 
 C<value> can be NULL.
 
 
 C<value> can be NULL.
 

+=head2 cp
+
+ cp src dest
+
+This copies a file from C<src> to C<dest> where C<dest> is
+either a destination filename or destination directory.
+
+=head2 cp-a
+
+ cp-a src dest
+
+This copies a file or directory from C<src> to C<dest>
+recursively using the C<cp -a> command.
+

 =head2 debug
 
  debug subcmd 'extraargs ...'
 =head2 debug
 
  debug subcmd 'extraargs ...'


@@ -415,6 +479,40 @@ There is no comprehensive help for this command.  You have
 to look at the file C<daemon/debug.c> in the libguestfs source
 to find out what you can do.
 
 to look at the file C<daemon/debug.c> in the libguestfs source
 to find out what you can do.
 

+=head2 df
+
+ df
+
+This command runs the C<df> command to report disk space used.
+
+This command is mostly useful for interactive sessions.  It
+is I<not> intended that you try to parse the output string.
+Use C<statvfs> from programs.
+
+=head2 df-h
+
+ df-h
+
+This command runs the C<df -h> command to report disk space used
+in human-readable format.
+
+This command is mostly useful for interactive sessions.  It
+is I<not> intended that you try to parse the output string.
+Use C<statvfs> from programs.
+
+=head2 dmesg
+
+ dmesg
+
+This returns the kernel messages (C<dmesg> output) from
+the guest kernel.  This is sometimes useful for extended
+debugging of problems.
+
+Another way to get the same information is to enable
+verbose messages with C<set-verbose> or by setting
+the environment variable C<LIBGUESTFS_DEBUG=1> before
+running the program.
+

 =head2 download
 
  download remotefilename (filename|-)
 =head2 download
 
  download remotefilename (filename|-)


@@ -428,6 +526,54 @@ See also C<upload>, C<cat>.
 
 Use C<-> instead of a filename to read/write from stdin/stdout.
 
 
 Use C<-> instead of a filename to read/write from stdin/stdout.
 

+=head2 drop-caches
+
+ drop-caches whattodrop
+
+This instructs the guest kernel to drop its page cache,
+and/or dentries and inode caches.  The parameter C<whattodrop>
+tells the kernel what precisely to drop, see
+L<http://linux-mm.org/Drop_Caches>
+
+Setting C<whattodrop> to 3 should drop everything.
+
+This automatically calls L<sync(2)> before the operation,
+so that the maximum guest memory is freed.
+
+=head2 du
+
+ du path
+
+This command runs the C<du -s> command to estimate file space
+usage for C<path>.
+
+C<path> can be a file or a directory.  If C<path> is a directory
+then the estimate includes the contents of the directory and all
+subdirectories (recursively).
+
+The result is the estimated size in I<kilobytes>
+(ie. units of 1024 bytes).
+
+=head2 e2fsck-f
+
+ e2fsck-f device
+
+This runs C<e2fsck -p -f device>, ie. runs the ext2/ext3
+filesystem checker on C<device>, noninteractively (C<-p>),
+even if the filesystem appears to be clean (C<-f>).
+
+This command is only needed because of C<resize2fs>
+(q.v.).  Normally you should use C<fsck>.
+
+=head2 equal
+
+ equal file1 file2
+
+This compares the two files C<file1> and C<file2> and returns
+true if their content is exactly equal, or false otherwise.
+
+The external L<cmp(1)> program is used for the comparison.
+

 =head2 exists
 
  exists path
 =head2 exists
 
  exists path


@@ -449,6 +595,35 @@ The exact command which runs is C<file -bsL path>.  Note in
 particular that the filename is not prepended to the output
 (the C<-b> option).
 
 particular that the filename is not prepended to the output
 (the C<-b> option).
 

+=head2 find
+
+ find directory
+
+This command lists out all files and directories, recursively,
+starting at C<directory>.  It is essentially equivalent to
+running the shell command C<find directory -print> but some
+post-processing happens on the output, described below.
+
+This returns a list of strings I<without any prefix>.  Thus
+if the directory structure was:
+
+ /tmp/a
+ /tmp/b
+ /tmp/c/d
+
+then the returned list from C<find> C</tmp> would be
+4 elements:
+
+ a
+ b
+ c
+ c/d
+
+If C<directory> is not a directory, then this command returns
+an error.
+
+The returned list is sorted.
+

 =head2 fsck
 
  fsck fstype device
 =head2 fsck
 
  fsck fstype device


@@ -481,6 +656,15 @@ Checking or repairing NTFS volumes is not supported
 
 This command is entirely equivalent to running C<fsck -a -t fstype device>.
 
 
 This command is entirely equivalent to running C<fsck -a -t fstype device>.
 

+=head2 get-append
+
+ get-append
+
+Return the additional kernel options which are added to the
+guest kernel command line.
+
+If C<NULL> then no options are added.
+

 =head2 get-autosync
 
  get-autosync
 =head2 get-autosync
 
  get-autosync


@@ -501,6 +685,20 @@ C<device>.
 This returns the ext2/3/4 filesystem UUID of the filesystem on
 C<device>.
 
 This returns the ext2/3/4 filesystem UUID of the filesystem on
 C<device>.
 

+=head2 get-memsize
+
+ get-memsize
+
+This gets the memory size in megabytes allocated to the
+qemu subprocess.
+
+If C<set-memsize> was not called
+on this handle, and if C<LIBGUESTFS_MEMSIZE> was not set,
+then this returns the compiled-in default value for memsize.
+
+For more information on the architecture of libguestfs,
+see L<guestfs(3)>.
+

 =head2 get-path
 
  get-path
 =head2 get-path
 
  get-path


@@ -534,6 +732,21 @@ For more information on states, see L<guestfs(3)>.
 
 This returns the verbose messages flag.
 
 
 This returns the verbose messages flag.
 

+=head2 glob-expand
+
+ glob-expand pattern
+
+This command searches for all the pathnames matching
+C<pattern> according to the wildcard expansion rules
+used by the shell.
+
+If no paths match, then this returns an empty list
+(note: not an error).
+
+It is just a wrapper around the C L<glob(3)> function
+with flags C<GLOB_MARK|GLOB_BRACE>.
+See that manual page for more details.
+

 =head2 grub-install
 
  grub-install root device
 =head2 grub-install
 
  grub-install root device


@@ -541,6 +754,58 @@ This returns the verbose messages flag.
 This command installs GRUB (the Grand Unified Bootloader) on
 C<device>, with the root directory being C<root>.
 
 This command installs GRUB (the Grand Unified Bootloader) on
 C<device>, with the root directory being C<root>.
 

+=head2 head
+
+ head path
+
+This command returns up to the first 10 lines of a file as
+a list of strings.
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+
+=head2 head-n
+
+ head-n nrlines path
+
+If the parameter C<nrlines> is a positive number, this returns the first
+C<nrlines> lines of the file C<path>.
+
+If the parameter C<nrlines> is a negative number, this returns lines
+from the file C<path>, excluding the last C<nrlines> lines.
+
+If the parameter C<nrlines> is zero, this returns an empty list.
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+
+=head2 hexdump
+
+ hexdump path
+
+This runs C<hexdump -C> on the given C<path>.  The result is
+the human-readable, canonical hex dump of the file.
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+
+=head2 initrd-list
+
+ initrd-list path
+
+This command lists out files contained in an initrd.
+
+The files are listed without any initial C</> character.  The
+files are listed in the order they appear (not necessarily
+alphabetical).  Directory names are listed as separate items.
+
+Old Linux kernels (2.4 and earlier) used a compressed ext2
+filesystem as initrd.  We I<only> support the newer initramfs
+format (compressed cpio files).
+

 =head2 is-busy
 
  is-busy
 =head2 is-busy
 
  is-busy


@@ -692,6 +957,14 @@ the path to the LV, such as C</dev/VG/LV>.
 You can also remove all LVs in a volume group by specifying
 the VG name, C</dev/VG>.
 
 You can also remove all LVs in a volume group by specifying
 the VG name, C</dev/VG>.
 

+=head2 lvresize
+
+ lvresize device mbytes
+
+This resizes (expands or shrinks) an existing LVM logical
+volume to C<mbytes>.  When reducing, data in the reduced part
+is lost.
+

 =head2 lvs
 
  lvs
 =head2 lvs
 
  lvs


@@ -724,14 +997,91 @@ Create a directory named C<path>.
 Create a directory named C<path>, creating any parent directories
 as necessary.  This is like the C<mkdir -p> shell command.
 
 Create a directory named C<path>, creating any parent directories
 as necessary.  This is like the C<mkdir -p> shell command.
 

+=head2 mkdtemp
+
+ mkdtemp template
+
+This command creates a temporary directory.  The
+C<template> parameter should be a full pathname for the
+temporary directory name with the final six characters being
+"XXXXXX".
+
+For example: "/tmp/myprogXXXXXX" or "/Temp/myprogXXXXXX",
+the second one being suitable for Windows filesystems.
+
+The name of the temporary directory that was created
+is returned.
+
+The temporary directory is created with mode 0700
+and is owned by root.
+
+The caller is responsible for deleting the temporary
+directory and its contents after use.
+
+See also: L<mkdtemp(3)>
+
+=head2 mkfifo
+
+ mkfifo mode path
+
+This call creates a FIFO (named pipe) called C<path> with
+mode C<mode>.  It is just a convenient wrapper around
+C<mknod>.
+

 =head2 mkfs
 
  mkfs fstype device
 
 This creates a filesystem on C<device> (usually a partition
 =head2 mkfs
 
  mkfs fstype device
 
 This creates a filesystem on C<device> (usually a partition

-of LVM logical volume).  The filesystem type is C<fstype>, for
+or LVM logical volume).  The filesystem type is C<fstype>, for

 example C<ext3>.
 
 example C<ext3>.
 

+=head2 mknod
+
+ mknod mode devmajor devminor path
+
+This call creates block or character special devices, or
+named pipes (FIFOs).
+
+The C<mode> parameter should be the mode, using the standard
+constants.  C<devmajor> and C<devminor> are the
+device major and minor numbers, only used when creating block
+and character special devices.
+
+=head2 mknod-b
+
+ mknod-b mode devmajor devminor path
+
+This call creates a block device node called C<path> with
+mode C<mode> and device major/minor C<devmajor> and C<devminor>.
+It is just a convenient wrapper around C<mknod>.
+
+=head2 mknod-c
+
+ mknod-c mode devmajor devminor path
+
+This call creates a char device node called C<path> with
+mode C<mode> and device major/minor C<devmajor> and C<devminor>.
+It is just a convenient wrapper around C<mknod>.
+
+=head2 mkswap
+
+ mkswap device
+
+Create a swap partition on C<device>.
+
+=head2 mkswap-L
+
+ mkswap-L label device
+
+Create a swap partition on C<device> with label C<label>.
+
+=head2 mkswap-U
+
+ mkswap-U uuid device
+
+Create a swap partition on C<device> with UUID C<uuid>.
+

 =head2 mount
 
  mount device mountpoint
 =head2 mount
 
  mount device mountpoint


@@ -753,6 +1103,14 @@ on the underlying device.
 The filesystem options C<sync> and C<noatime> are set with this
 call, in order to improve reliability.
 
 The filesystem options C<sync> and C<noatime> are set with this
 call, in order to improve reliability.
 

+=head2 mount-loop
+
+ mount-loop file mountpoint
+
+This command lets you mount C<file> (a filesystem image
+in a file) on a mount point.  It is entirely equivalent to
+the command C<mount -o loop file mountpoint>.
+

 =head2 mount-options
 
  mount-options options device mountpoint
 =head2 mount-options
 
  mount-options options device mountpoint


@@ -785,6 +1143,38 @@ the list of devices (eg. C</dev/sda1>, C</dev/VG/LV>).
 
 Some internal mounts are not shown.
 
 
 Some internal mounts are not shown.
 

+=head2 mv
+
+ mv src dest
+
+This moves a file from C<src> to C<dest> where C<dest> is
+either a destination filename or destination directory.
+
+=head2 ntfs-3g-probe
+
+ ntfs-3g-probe true|false device
+
+This command runs the L<ntfs-3g.probe(8)> command which probes
+an NTFS C<device> for mountability.  (Not all NTFS volumes can
+be mounted read-write, and some cannot be mounted at all).
+
+C<rw> is a boolean flag.  Set it to true if you want to test
+if the volume can be mounted read-write.  Set it to false if
+you want to test if the volume can be mounted read-only.
+
+The return value is an integer which C<0> if the operation
+would succeed, or some non-zero value documented in the
+L<ntfs-3g.probe(8)> manual page.
+
+=head2 ping-daemon
+
+ ping-daemon
+
+This is a test probe into the guestfs daemon running inside
+the qemu subprocess.  Calling this function checks that the
+daemon responds to the ping message, without affecting the daemon
+or attached block device(s) in any other way.
+

 =head2 pvcreate
 
  pvcreate device
 =head2 pvcreate
 
  pvcreate device


@@ -804,6 +1194,13 @@ The implementation uses the C<pvremove> command which refuses to
 wipe physical volumes that contain any volume groups, so you have
 to remove those first.
 
 wipe physical volumes that contain any volume groups, so you have
 to remove those first.
 

+=head2 pvresize
+
+ pvresize device
+
+This resizes (expands or shrinks) an existing LVM physical
+volume to match the new size of the underlying device.
+

 =head2 pvs
 
  pvs
 =head2 pvs
 
  pvs


@@ -837,6 +1234,19 @@ Note that this function cannot correctly handle binary files
 as end of line).  For those you need to use the C<read-file>
 function which has a more complex interface.
 
 as end of line).  For those you need to use the C<read-file>
 function which has a more complex interface.
 

+=head2 resize2fs
+
+ resize2fs device
+
+This resizes an ext2 or ext3 filesystem to match the size of
+the underlying device.
+
+I<Note:> It is sometimes required that you run C<e2fsck-f>
+on the C<device> before calling this command.  For unknown reasons
+C<resize2fs> sometimes gives an error about this and sometimes not.
+In any case, it is always safe to call C<e2fsck-f> before
+calling this function.
+

 =head2 rm
 
  rm path
 =head2 rm
 
  rm path


@@ -857,6 +1267,57 @@ command.
 
 Remove the single directory C<path>.
 
 
 Remove the single directory C<path>.
 

+=head2 scrub-device
+
+ scrub-device device
+
+This command writes patterns over C<device> to make data retrieval
+more difficult.
+
+It is an interface to the L<scrub(1)> program.  See that
+manual page for more details.
+
+B<This command is dangerous.  Without careful use you
+can easily destroy all your data>.
+
+=head2 scrub-file
+
+ scrub-file file
+
+This command writes patterns over a file to make data retrieval
+more difficult.
+
+The file is I<removed> after scrubbing.
+
+It is an interface to the L<scrub(1)> program.  See that
+manual page for more details.
+
+=head2 scrub-freespace
+
+ scrub-freespace dir
+
+This command creates the directory C<dir> and then fills it
+with files until the filesystem is full, and scrubs the files
+as for C<scrub-file>, and deletes them.
+The intention is to scrub any free space on the partition
+containing C<dir>.
+
+It is an interface to the L<scrub(1)> program.  See that
+manual page for more details.
+
+=head2 set-append | append
+
+ set-append append
+
+This function is used to add additional options to the
+guest kernel command line.
+
+The default is C<NULL> unless overridden by setting
+C<LIBGUESTFS_APPEND> environment variable.
+
+Setting C<append> to C<NULL> means I<no> additional options
+are passed (libguestfs always adds a few of its own).
+

 =head2 set-autosync | autosync
 
  set-autosync true|false
 =head2 set-autosync | autosync
 
  set-autosync true|false


@@ -892,6 +1353,21 @@ L<tune2fs(8)> manpage.
 You can use either C<tune2fs-l> or C<get-e2uuid>
 to return the existing UUID of a filesystem.
 
 You can use either C<tune2fs-l> or C<get-e2uuid>
 to return the existing UUID of a filesystem.
 

+=head2 set-memsize | memsize
+
+ set-memsize memsize
+
+This sets the memory size in megabytes allocated to the
+qemu subprocess.  This only has any effect if called before
+C<launch>.
+
+You can also change this by setting the environment
+variable C<LIBGUESTFS_MEMSIZE> before the handle is
+created.
+
+For more information on the architecture of libguestfs,
+see L<guestfs(3)>.
+

 =head2 set-path | path
 
  set-path path
 =head2 set-path | path
 
  set-path path


@@ -901,9 +1377,6 @@ Set the path that libguestfs searches for kernel and initrd.img.
 The default is C<$libdir/guestfs> unless overridden by setting
 C<LIBGUESTFS_PATH> environment variable.
 
 The default is C<$libdir/guestfs> unless overridden by setting
 C<LIBGUESTFS_PATH> environment variable.
 

-The string C<path> is stashed in the libguestfs handle, so the caller
-must make sure it remains valid for the lifetime of the handle.
-

 Setting C<path> to C<NULL> restores the default path.
 
 =head2 set-qemu | qemu
 Setting C<path> to C<NULL> restores the default path.
 
 =head2 set-qemu | qemu


@@ -918,9 +1391,6 @@ configure script.
 You can also override this by setting the C<LIBGUESTFS_QEMU>
 environment variable.
 
 You can also override this by setting the C<LIBGUESTFS_QEMU>
 environment variable.
 

-The string C<qemu> is stashed in the libguestfs handle, so the caller
-must make sure it remains valid for the lifetime of the handle.
-

 Setting C<qemu> to C<NULL> restores the default qemu binary.
 
 =head2 set-verbose | verbose
 Setting C<qemu> to C<NULL> restores the default qemu binary.
 
 =head2 set-verbose | verbose


@@ -956,9 +1426,85 @@ To create a single partition occupying the whole disk, you would
 pass C<lines> as a single element list, when the single element being
 the string C<,> (comma).
 
 pass C<lines> as a single element list, when the single element being
 the string C<,> (comma).
 

+See also: C<sfdisk-l>, C<sfdisk-N>
+
+B<This command is dangerous.  Without careful use you
+can easily destroy all your data>.
+
+=head2 sfdisk-N
+
+ sfdisk-N device partnum cyls heads sectors line
+
+This runs L<sfdisk(8)> option to modify just the single
+partition C<n> (note: C<n> counts from 1).
+
+For other parameters, see C<sfdisk>.  You should usually
+pass C<0> for the cyls/heads/sectors parameters.
+

 B<This command is dangerous.  Without careful use you
 can easily destroy all your data>.
 
 B<This command is dangerous.  Without careful use you
 can easily destroy all your data>.
 

+=head2 sfdisk-disk-geometry
+
+ sfdisk-disk-geometry device
+
+This displays the disk geometry of C<device> read from the
+partition table.  Especially in the case where the underlying
+block device has been resized, this can be different from the
+kernel's idea of the geometry (see C<sfdisk-kernel-geometry>).
+
+The result is in human-readable format, and not designed to
+be parsed.
+
+=head2 sfdisk-kernel-geometry
+
+ sfdisk-kernel-geometry device
+
+This displays the kernel's idea of the geometry of C<device>.
+
+The result is in human-readable format, and not designed to
+be parsed.
+
+=head2 sfdisk-l
+
+ sfdisk-l device
+
+This displays the partition table on C<device>, in the
+human-readable output of the L<sfdisk(8)> command.  It is
+not intended to be parsed.
+
+=head2 sh
+
+ sh command
+
+This call runs a command from the guest filesystem via the
+guest's C</bin/sh>.
+
+This is like C<command>, but passes the command to:
+
+ /bin/sh -c "command"
+
+Depending on the guest's shell, this usually results in
+wildcards being expanded, shell expressions being interpolated
+and so on.
+
+All the provisos about C<command> apply to this call.
+
+=head2 sh-lines
+
+ sh-lines command
+
+This is the same as C<sh>, but splits the result
+into a list of lines.
+
+See also: C<command-lines>
+
+=head2 sleep
+
+ sleep secs
+
+Sleep for C<secs> seconds.
+

 =head2 stat
 
  stat path
 =head2 stat
 
  stat path


@@ -977,6 +1523,35 @@ C<path> should be a file or directory in the mounted file system
 
 This is the same as the C<statvfs(2)> system call.
 
 
 This is the same as the C<statvfs(2)> system call.
 

+=head2 strings
+
+ strings path
+
+This runs the L<strings(1)> command on a file and returns
+the list of printable strings found.
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+
+=head2 strings-e
+
+ strings-e encoding path
+
+This is like the C<strings> command, but allows you to
+specify the encoding.
+
+See the L<strings(1)> manpage for the full list of encodings.
+
+Commonly useful encodings are C<l> (lower case L) which will
+show strings inside Windows/x86 files.
+
+The returned strings are transcoded to UTF-8.
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+

 =head2 sync
 
  sync
 =head2 sync
 
  sync


@@ -987,6 +1562,33 @@ underlying disk image.
 You should always call this if you have modified a disk image, before
 closing the handle.
 
 You should always call this if you have modified a disk image, before
 closing the handle.
 

+=head2 tail
+
+ tail path
+
+This command returns up to the last 10 lines of a file as
+a list of strings.
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+
+=head2 tail-n
+
+ tail-n nrlines path
+
+If the parameter C<nrlines> is a positive number, this returns the last
+C<nrlines> lines of the file C<path>.
+
+If the parameter C<nrlines> is a negative number, this returns lines
+from the file C<path>, starting with the C<-nrlines>th line.
+
+If the parameter C<nrlines> is zero, this returns an empty list.
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+

 =head2 tar-in
 
  tar-in (tarfile|-) directory
 =head2 tar-in
 
  tar-in (tarfile|-) directory


@@ -1051,6 +1653,22 @@ manpage for more details.  The list of fields returned isn't
 clearly defined, and depends on both the version of C<tune2fs>
 that libguestfs was built against, and the filesystem itself.
 
 clearly defined, and depends on both the version of C<tune2fs>
 that libguestfs was built against, and the filesystem itself.
 

+=head2 umask
+
+ umask mask
+
+This function sets the mask used for creating new files and
+device nodes to C<mask & 0777>.
+
+Typical umask values would be C<022> which creates new files
+with permissions like "-rw-r--r--" or "-rwxr-xr-x", and
+C<002> which creates new files with permissions like
+"-rw-rw-r--" or "-rwxrwxr-x".
+
+See also L<umask(2)>, C<mknod>, C<mkdir>.
+
+This call returns the previous umask.
+

 =head2 umount | unmount
 
  umount pathordevice
 =head2 umount | unmount
 
  umount pathordevice


@@ -1080,6 +1698,33 @@ See also C<download>.
 
 Use C<-> instead of a filename to read/write from stdin/stdout.
 
 
 Use C<-> instead of a filename to read/write from stdin/stdout.
 

+=head2 vg-activate
+
+ vg-activate true|false 'volgroups ...'
+
+This command activates or (if C<activate> is false) deactivates
+all logical volumes in the listed volume groups C<volgroups>.
+If activated, then they are made known to the
+kernel, ie. they appear as C</dev/mapper> devices.  If deactivated,
+then those devices disappear.
+
+This command is the same as running C<vgchange -a y|n volgroups...>
+
+Note that if C<volgroups> is an empty list then B<all> volume groups
+are activated or deactivated.
+
+=head2 vg-activate-all
+
+ vg-activate-all true|false
+
+This command activates or (if C<activate> is false) deactivates
+all logical volumes in all volume groups.
+If activated, then they are made known to the
+kernel, ie. they appear as C</dev/mapper> devices.  If deactivated,
+then those devices disappear.
+
+This command is the same as running C<vgchange -a y|n>
+

 =head2 vgcreate
 
  vgcreate volgroup 'physvols ...'
 =head2 vgcreate
 
  vgcreate volgroup 'physvols ...'


@@ -1115,6 +1760,27 @@ See also C<vgs-full>.
 List all the volumes groups detected.  This is the equivalent
 of the L<vgs(8)> command.  The "full" version includes all fields.
 
 List all the volumes groups detected.  This is the equivalent
 of the L<vgs(8)> command.  The "full" version includes all fields.
 

+=head2 wc-c
+
+ wc-c path
+
+This command counts the characters in a file, using the
+C<wc -c> external command.
+
+=head2 wc-l
+
+ wc-l path
+
+This command counts the lines in a file, using the
+C<wc -l> external command.
+
+=head2 wc-w
+
+ wc-w path
+
+This command counts the words in a file, using the
+C<wc -w> external command.
+

 =head2 write-file
 
  write-file path content size
 =head2 write-file
 
  write-file path content size


@@ -1127,6 +1793,11 @@ As a special case, if C<size> is C<0>
 then the length is calculated using C<strlen> (so in this case
 the content cannot contain embedded ASCII NULs).
 
 then the length is calculated using C<strlen> (so in this case
 the content cannot contain embedded ASCII NULs).
 

+I<NB.> Owing to a bug, writing content containing ASCII NUL
+characters does I<not> work, even if the length is specified.
+We hope to resolve this bug in a future version.  In the meantime
+use C<upload>.
+

 Because of the message protocol, there is a transfer limit 
 of somewhere between 2MB and 4MB.  To transfer large files you should use
 FTP.
 Because of the message protocol, there is a transfer limit 
 of somewhere between 2MB and 4MB.  To transfer large files you should use
 FTP.


@@ -1141,3 +1812,20 @@ How many blocks are zeroed isn't specified (but it's I<not> enough
 to securely wipe the device).  It should be sufficient to remove
 any partition tables, filesystem superblocks and so on.
 
 to securely wipe the device).  It should be sufficient to remove
 any partition tables, filesystem superblocks and so on.
 

+See also: C<scrub-device>.
+
+=head2 zerofree
+
+ zerofree device
+
+This runs the I<zerofree> program on C<device>.  This program
+claims to zero unused inodes and disk blocks on an ext2/3
+filesystem, thus making it possible to compress the filesystem
+more effectively.
+
+You should B<not> run this program if the filesystem is
+mounted.
+
+It is possible that using this program can damage the filesystem
+or data on the filesystem.
+