Allow qemu binary to be overridden at runtime.

[libguestfs.git] / guestfish-actions.pod

diff --git a/guestfish-actions.pod b/guestfish-actions.pod
index d47e9bf..4403cb0 100644 (file)
--- a/guestfish-actions.pod
+++ b/guestfish-actions.pod
@@ -182,6 +182,105 @@ how files are saved.
 
 Set the value associated with C<path> to C<value>.
 
 
 Set the value associated with C<path> to C<value>.
 

+=head2 blockdev-flushbufs
+
+ blockdev-flushbufs device
+
+This tells the kernel to flush internal buffers associated
+with C<device>.
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-getbsz
+
+ blockdev-getbsz device
+
+This returns the block size of a device.
+
+(Note this is different from both I<size in blocks> and
+I<filesystem block size>).
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-getro
+
+ blockdev-getro device
+
+Returns a boolean indicating if the block device is read-only
+(true if read-only, false if not).
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-getsize64
+
+ blockdev-getsize64 device
+
+This returns the size of the device in bytes.
+
+See also C<blockdev_getsz>.
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-getss
+
+ blockdev-getss device
+
+This returns the size of sectors on a block device.
+Usually 512, but can be larger for modern devices.
+
+(Note, this is not the size in sectors, use C<blockdev_getsz>
+for that).
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-getsz
+
+ blockdev-getsz device
+
+This returns the size of the device in units of 512-byte sectors
+(even if the sectorsize isn't 512 bytes ... weird).
+
+See also C<blockdev_getss> for the real sector size of
+the device, and C<blockdev_getsize64> for the more
+useful I<size in bytes>.
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-rereadpt
+
+ blockdev-rereadpt device
+
+Reread the partition table on C<device>.
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-setbsz
+
+ blockdev-setbsz device blocksize
+
+This sets the block size of a device.
+
+(Note this is different from both I<size in blocks> and
+I<filesystem block size>).
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-setro
+
+ blockdev-setro device
+
+Sets the block device named C<device> to read-only.
+
+This uses the L<blockdev(8)> command.
+
+=head2 blockdev-setrw
+
+ blockdev-setrw device
+
+Sets the block device named C<device> to read-write.
+
+This uses the L<blockdev(8)> command.
+

 =head2 cat
 
  cat path
 =head2 cat
 
  cat path


@@ -190,9 +289,58 @@ Return the contents of the file named C<path>.
 
 Note that this function cannot correctly handle binary files
 (specifically, files containing C<\0> character which is treated
 
 Note that this function cannot correctly handle binary files
 (specifically, files containing C<\0> character which is treated

-as end of string).  For those you need to use the C<read_file>
+as end of string).  For those you need to use the C<download>

 function which has a more complex interface.
 
 function which has a more complex interface.
 

+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 checksum
+
+ checksum csumtype path
+
+This call computes the MD5, SHAx or CRC checksum of the
+file named C<path>.
+
+The type of checksum to compute is given by the C<csumtype>
+parameter which must have one of the following values:
+
+=over 4
+
+=item C<crc>
+
+Compute the cyclic redundancy check (CRC) specified by POSIX
+for the C<cksum> command.
+
+=item C<md5>
+
+Compute the MD5 hash (using the C<md5sum> program).
+
+=item C<sha1>
+
+Compute the SHA1 hash (using the C<sha1sum> program).
+
+=item C<sha224>
+
+Compute the SHA224 hash (using the C<sha224sum> program).
+
+=item C<sha256>
+
+Compute the SHA256 hash (using the C<sha256sum> program).
+
+=item C<sha384>
+
+Compute the SHA384 hash (using the C<sha384sum> program).
+
+=item C<sha512>
+
+Compute the SHA512 hash (using the C<sha512sum> program).
+
+=back
+
+The checksum is returned as a printable string.
+

 =head2 chmod
 
  chmod mode path
 =head2 chmod
 
  chmod mode path


@@ -210,6 +358,38 @@ Only numeric uid and gid are supported.  If you want to use
 names, you will need to locate and parse the password file
 yourself (Augeas support makes this relatively easy).
 
 names, you will need to locate and parse the password file
 yourself (Augeas support makes this relatively easy).
 

+=head2 command
+
+ command arguments,...
+
+This call runs a command from the guest filesystem.  The
+filesystem must be mounted, and must contain a compatible
+operating system (ie. something Linux, with the same
+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
+non-empty (ie. must contain a program name).
+
+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
+first parameter.
+
+Shared libraries and data files required by the program
+must be available on filesystems which are mounted in the
+correct places.  It is the caller's responsibility to ensure
+all filesystems that are needed are mounted at the right
+locations.
+
+=head2 command-lines
+
+ command-lines arguments,...
+
+This is the same as C<command>, but splits the
+result into a list of lines.
+

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


@@ -223,6 +403,40 @@ The first character of C<param> string must be a C<-> (dash).
 
 C<value> can be NULL.
 
 
 C<value> can be NULL.
 

+=head2 download
+
+ download remotefilename (filename|-)
+
+Download file C<remotefilename> and save it as C<filename>
+on the local machine.
+
+C<filename> can also be a named pipe.
+
+See also C<upload>, C<cat>.
+
+Use C<-> instead of a filename to read/write from stdin/stdout.
+
+=head2 exists
+
+ exists path
+
+This returns C<true> if and only if there is a file, directory
+(or anything) with the given C<path> name.
+
+See also C<is_file>, C<is_dir>, C<stat>.
+
+=head2 file
+
+ file path
+
+This call uses the standard L<file(1)> command to determine
+the type or contents of the file.  This also works on devices,
+for example to find out whether a partition contains a filesystem.
+
+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).
+

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


@@ -238,12 +452,86 @@ Return the current search path.
 This is always non-NULL.  If it wasn't set already, then this will
 return the default path.
 
 This is always non-NULL.  If it wasn't set already, then this will
 return the default path.
 

+=head2 get-qemu
+
+ get-qemu
+
+Return the current qemu binary.
+
+This is always non-NULL.  If it wasn't set already, then this will
+return the default qemu binary name.
+
+=head2 get-state
+
+ get-state
+
+This returns the current state as an opaque integer.  This is
+only useful for printing debug and internal error messages.
+
+For more information on states, see L<guestfs(3)>.
+

 =head2 get-verbose
 
  get-verbose
 
 This returns the verbose messages flag.
 
 =head2 get-verbose
 
  get-verbose
 
 This returns the verbose messages flag.
 

+=head2 is-busy
+
+ is-busy
+
+This returns true iff this handle is busy processing a command
+(in the C<BUSY> state).
+
+For more information on states, see L<guestfs(3)>.
+
+=head2 is-config
+
+ is-config
+
+This returns true iff this handle is being configured
+(in the C<CONFIG> state).
+
+For more information on states, see L<guestfs(3)>.
+
+=head2 is-dir
+
+ is-dir path
+
+This returns C<true> if and only if there is a directory
+with the given C<path> name.  Note that it returns false for
+other objects like files.
+
+See also C<stat>.
+
+=head2 is-file
+
+ is-file path
+
+This returns C<true> if and only if there is a file
+with the given C<path> name.  Note that it returns false for
+other objects like directories.
+
+See also C<stat>.
+
+=head2 is-launching
+
+ is-launching
+
+This returns true iff this handle is launching the subprocess
+(in the C<LAUNCHING> state).
+
+For more information on states, see L<guestfs(3)>.
+
+=head2 is-ready
+
+ is-ready
+
+This returns true iff this handle is ready to accept commands
+(in the C<READY> state).
+
+For more information on states, see L<guestfs(3)>.
+

 =head2 kill-subprocess
 
  kill-subprocess
 =head2 kill-subprocess
 
  kill-subprocess


@@ -300,6 +588,35 @@ hidden files are shown.
 This command is mostly useful for interactive sessions.  Programs
 should probably use C<readdir> instead.
 
 This command is mostly useful for interactive sessions.  Programs
 should probably use C<readdir> instead.
 

+=head2 lstat
+
+ lstat path
+
+Returns file information for the given C<path>.
+
+This is the same as C<stat> except that if C<path>
+is a symbolic link, then the link is stat-ed, not the file it
+refers to.
+
+This is the same as the C<lstat(2)> system call.
+
+=head2 lvcreate
+
+ lvcreate logvol volgroup mbytes
+
+This creates an LVM volume group called C<logvol>
+on the volume group C<volgroup>, with C<size> megabytes.
+
+=head2 lvm-remove-all
+
+ lvm-remove-all
+
+This command removes all LVM logical volumes, volume groups
+and physical volumes.
+
+B<This command is dangerous.  Without careful use you
+can easily destroy all your data>.
+

 =head2 lvs
 
  lvs
 =head2 lvs
 
  lvs


@@ -332,6 +649,14 @@ 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 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
+example C<ext3>.
+

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


@@ -353,6 +678,23 @@ 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 mounts
+
+ mounts
+
+This returns the list of currently mounted filesystems.  It returns
+the list of devices (eg. C</dev/sda1>, C</dev/VG/LV>).
+
+Some internal mounts are not shown.
+
+=head2 pvcreate
+
+ pvcreate device
+
+This creates an LVM physical volume on the named C<device>,
+where C<device> should usually be a partition name such
+as C</dev/sda1>.
+

 =head2 pvs
 
  pvs
 =head2 pvs
 
  pvs


@@ -428,6 +770,23 @@ must make sure it remains valid for the lifetime of the handle.
 
 Setting C<path> to C<NULL> restores the default path.
 
 
 Setting C<path> to C<NULL> restores the default path.
 

+=head2 set-qemu | qemu
+
+ set-qemu qemu
+
+Set the qemu binary that we will use.
+
+The default is chosen when the library was compiled by the
+configure script.
+
+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
 
  set-verbose true|false
 =head2 set-verbose | verbose
 
  set-verbose true|false


@@ -437,6 +796,51 @@ If C<verbose> is true, this turns on verbose messages (to C<stderr>).
 Verbose messages are disabled unless the environment variable
 C<LIBGUESTFS_DEBUG> is defined and set to C<1>.
 
 Verbose messages are disabled unless the environment variable
 C<LIBGUESTFS_DEBUG> is defined and set to C<1>.
 

+=head2 sfdisk
+
+ sfdisk device cyls heads sectors lines,...
+
+This is a direct interface to the L<sfdisk(8)> program for creating
+partitions on block devices.
+
+C<device> should be a block device, for example C</dev/sda>.
+
+C<cyls>, C<heads> and C<sectors> are the number of cylinders, heads
+and sectors on the device, which are passed directly to sfdisk as
+the I<-C>, I<-H> and I<-S> parameters.  If you pass C<0> for any
+of these, then the corresponding parameter is omitted.  Usually for
+'large' disks, you can just pass C<0> for these, but for small
+(floppy-sized) disks, sfdisk (or rather, the kernel) cannot work
+out the right geometry and you will need to tell it.
+
+C<lines> is a list of lines that we feed to C<sfdisk>.  For more
+information refer to the L<sfdisk(8)> manpage.
+
+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).
+
+B<This command is dangerous.  Without careful use you
+can easily destroy all your data>.
+
+=head2 stat
+
+ stat path
+
+Returns file information for the given C<path>.
+
+This is the same as the C<stat(2)> system call.
+
+=head2 statvfs
+
+ statvfs path
+
+Returns file system statistics for any mounted file system.
+C<path> should be a file or directory in the mounted file system
+(typically it is the mount point itself, but it doesn't need to be).
+
+This is the same as the C<statvfs(2)> system call.
+

 =head2 sync
 
  sync
 =head2 sync
 
  sync


@@ -447,6 +851,50 @@ 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 tar-in
+
+ tar-in (tarfile|-) directory
+
+This command uploads and unpacks local file C<tarfile> (an
+I<uncompressed> tar file) into C<directory>.
+
+To upload a compressed tarball, use C<tgz_in>.
+
+Use C<-> instead of a filename to read/write from stdin/stdout.
+
+=head2 tar-out
+
+ tar-out directory (tarfile|-)
+
+This command packs the contents of C<directory> and downloads
+it to local file C<tarfile>.
+
+To download a compressed tarball, use C<tgz_out>.
+
+Use C<-> instead of a filename to read/write from stdin/stdout.
+
+=head2 tgz-in
+
+ tgz-in (tarball|-) directory
+
+This command uploads and unpacks local file C<tarball> (a
+I<gzip compressed> tar file) into C<directory>.
+
+To upload an uncompressed tarball, use C<tar_in>.
+
+Use C<-> instead of a filename to read/write from stdin/stdout.
+
+=head2 tgz-out
+
+ tgz-out directory (tarball|-)
+
+This command packs the contents of C<directory> and downloads
+it to local file C<tarball>.
+
+To download an uncompressed tarball, use C<tar_out>.
+
+Use C<-> instead of a filename to read/write from stdin/stdout.
+

 =head2 touch
 
  touch path
 =head2 touch
 
  touch path


@@ -455,6 +903,54 @@ Touch acts like the L<touch(1)> command.  It can be used to
 update the timestamps on a file, or, if the file does not exist,
 to create a new zero-length file.
 
 update the timestamps on a file, or, if the file does not exist,
 to create a new zero-length file.
 

+=head2 tune2fs-l
+
+ tune2fs-l device
+
+This returns the contents of the ext2 or ext3 filesystem superblock
+on C<device>.
+
+It is the same as running C<tune2fs -l device>.  See L<tune2fs(8)>
+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.
+
+=head2 umount | unmount
+
+ umount pathordevice
+
+This unmounts the given filesystem.  The filesystem may be
+specified either by its mountpoint (path) or the device which
+contains the filesystem.
+
+=head2 umount-all | unmount-all
+
+ umount-all
+
+This unmounts all mounted filesystems.
+
+Some internal mounts are not unmounted by this call.
+
+=head2 upload
+
+ upload (filename|-) remotefilename
+
+Upload local file C<filename> to C<remotefilename> on the
+filesystem.
+
+C<filename> can also be a named pipe.
+
+See also C<download>.
+
+Use C<-> instead of a filename to read/write from stdin/stdout.
+
+=head2 vgcreate
+
+ vgcreate volgroup physvols,...
+
+This creates an LVM volume group called C<volgroup>
+from the non-empty list of physical volumes C<physvols>.
+

 =head2 vgs
 
  vgs
 =head2 vgs
 
  vgs


@@ -474,3 +970,19 @@ 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 write-file
+
+ write-file path content size
+
+This call creates a file called C<path>.  The contents of the
+file is the string C<content> (which can contain any 8 bit data),
+with length C<size>.
+
+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).
+
+Because of the message protocol, there is a transfer limit 
+of somewhere between 2MB and 4MB.  To transfer large files you should use
+FTP.
+