Add support for zerofree command.

[libguestfs.git] / guestfish-actions.pod

diff --git a/guestfish-actions.pod b/guestfish-actions.pod
index c31905a..7b5a4be 100644 (file)
--- a/guestfish-actions.pod
+++ b/guestfish-actions.pod
@@ -372,6 +372,13 @@ 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).
 
 Subsequent elements are parameters.  The list must be
 non-empty (ie. must contain a program name).
 

+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<$PATH> environment variable will contain at least
 C</usr/bin> and C</bin>.  If you require a program from
 another location, you should provide the full path in the
 The C<$PATH> environment variable will contain at least
 C</usr/bin> and C</bin>.  If you require a program from
 another location, you should provide the full path in the


@@ -383,6 +390,10 @@ 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 +401,10 @@ 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.
 

+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


@@ -429,6 +444,19 @@ 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 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|-)


@@ -456,6 +484,15 @@ 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.
 
 This automatically calls L<sync(2)> before the operation,
 so that the maximum guest memory is freed.
 

+=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


@@ -509,6 +546,15 @@ 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


@@ -569,6 +615,17 @@ 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 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 is-busy
 
  is-busy
 =head2 is-busy
 
  is-busy


@@ -757,7 +814,7 @@ as necessary.  This is like the C<mkdir -p> shell command.
  mkfs fstype device
 
 This creates a filesystem on C<device> (usually a partition
  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>.
 
 =head2 mount
 example C<ext3>.
 
 =head2 mount


@@ -820,6 +877,15 @@ Some internal mounts are not shown.
 This moves a file from C<src> to C<dest> where C<dest> is
 either a destination filename or destination directory.
 
 This moves a file from C<src> to C<dest> where C<dest> is
 either a destination filename or destination directory.
 

+=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


@@ -892,6 +958,19 @@ command.
 
 Remove the single directory C<path>.
 
 
 Remove the single directory C<path>.
 

+=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


@@ -936,9 +1015,6 @@ 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


@@ -953,9 +1029,6 @@ 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


@@ -1012,6 +1085,35 @@ 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


@@ -1162,6 +1264,11 @@ 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.


@@ -1176,3 +1283,18 @@ 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.
 

+=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.
+