daemon error handling: recursive_mkdir shouldn't need to set errno.

[libguestfs.git] / guestfish.pod

diff --git a/guestfish.pod b/guestfish.pod
index d24c162..13a9fa7 100644 (file)
--- a/guestfish.pod
+++ b/guestfish.pod
@@ -2,18 +2,36 @@
 
 =head1 NAME
 
 
 =head1 NAME
 

-guestfish - the libguestfs filesystem interactive shell
+guestfish - the libguestfs Filesystem Interactive SHell

 
 =head1 SYNOPSIS
 
  guestfish [--options] [commands]
 
 
 =head1 SYNOPSIS
 
  guestfish [--options] [commands]
 

+ guestfish
+
+ guestfish -a disk.img
+
+ guestfish -a disk.img -m dev[:mountpoint]
+

  guestfish -i libvirt-domain
 
  guestfish -i libvirt-domain
 

- guestfish -i disk-image(s)
+ guestfish -i disk.img [disk.img ...]

 
 =head1 EXAMPLES
 
 
 =head1 EXAMPLES
 

+=head2 As an interactive shell
+
+ $ guestfish
+ 
+ Welcome to guestfish, the libguestfs filesystem interactive shell for
+ editing virtual machine filesystems.
+ 
+ Type: 'help' for help with commands
+       'quit' to quit the shell
+ 
+ ><fs> help
+

 =head2 From shell scripts
 
 Create a new C</etc/motd> file in a guest:
 =head2 From shell scripts
 
 Create a new C</etc/motd> file in a guest:


@@ -21,55 +39,56 @@ Create a new C</etc/motd> file in a guest:
  guestfish <<_EOF_
  add disk.img
  run
  guestfish <<_EOF_
  add disk.img
  run

- mount /dev/VolGroup00/LogVol00 /
- write_file /etc/motd "Hello users" 0
+ mount /dev/vg_guest/lv_root /
+ write_file /etc/motd "Welcome, new users" 0

  _EOF_
 
  _EOF_
 

-List the LVs in a guest:
+List the LVM logical volumes in a guest:

 
 

- guestfish <<_EOF_
- add disk.img
+ guestfish -a disk.img --ro <<_EOF_

  run
  lvs
  _EOF_
 
  run
  lvs
  _EOF_
 

-=head2 On the command line
+=head2 On one command line

 
 

-List the LVM PVs in a guest image:
+Update C</etc/resolv.conf> in a guest:

 
 

- guestfish add disk.img : run : pvs
+ guestfish \
+   add disk.img : run : mount /dev/vg_guest/lv_root / : \
+   write-file /etc/resolv.conf "nameserver 1.2.3.4" 0

 
 

-Remove C</boot/grub/menu.lst> (in reality not such a great idea):
+Edit C</boot/grub/grub.conf> interactively:

 
  guestfish --add disk.img \
 
  guestfish --add disk.img \

-   --mount /dev/VolGroup00/LogVol00 \
+   --mount /dev/vg_guest/lv_root \

    --mount /dev/sda1:/boot \
    --mount /dev/sda1:/boot \

-   rm /boot/grub/menu.lst
+   edit /boot/grub/grub.conf

 
 

-=head2 As an interactive shell
+=head2 Using virt-inspector

 
 

- $ guestfish
+Use the I<-i> option to get virt-inspector to mount
+the filesystems automatically as they would be mounted
+in the virtual machine:

 
 

- Welcome to guestfish, the libguestfs filesystem interactive shell for
- editing virtual machine filesystems.
-
- Type: 'help' for help with commands
-       'quit' to quit the shell
-
- ><fs> help
+ guestfish --ro -i disk.img cat /etc/group

 
 =head2 As a script interpreter
 
 
 =head2 As a script interpreter
 

+Create a 50MB disk containing an ext2-formatted partition:
+

  #!/usr/bin/guestfish -f
  #!/usr/bin/guestfish -f

- alloc /tmp/output.img 10M
+ alloc /tmp/output.img 50M

  run
  run

- sfdisk /dev/sda 0 0 0 ,
+ part-disk /dev/sda mbr

  mkfs ext2 /dev/sda1
 
 =head2 Remote control
 
  mkfs ext2 /dev/sda1
 
 =head2 Remote control
 

- eval `guestfish --listen`
- guestfish --remote cmd
+ eval `guestfish --listen --ro`
+ guestfish --remote add disk.img
+ guestfish --remote run
+ guestfish --remote lvs

 
 =head1 DESCRIPTION
 
 
 =head1 DESCRIPTION
 


@@ -77,6 +96,16 @@ Guestfish is a shell and command-line tool for examining and modifying
 virtual machine filesystems.  It uses libguestfs and exposes all of
 the functionality of the guestfs API, see L<guestfs(3)>.
 
 virtual machine filesystems.  It uses libguestfs and exposes all of
 the functionality of the guestfs API, see L<guestfs(3)>.
 

+Guestfish gives you structured access to the libguestfs API, from
+shell scripts or the command line or interactively.  If you want to
+rescue a broken virtual machine image, you might want to look at the
+L<virt-rescue(1)> command.
+
+Using guestfish in read/write mode on live virtual machines can be
+dangerous, potentially causing disk corruption.  Use the I<--ro>
+(read-only) option to use guestfish safely if the disk image or
+virtual machine might be live.
+

 =head1 OPTIONS
 
 =over 4
 =head1 OPTIONS
 
 =over 4


@@ -152,6 +181,11 @@ You have to mount something on C</> before most commands will work.
 If any C<-m> or C<--mount> options are given, the guest is
 automatically launched.
 
 If any C<-m> or C<--mount> options are given, the guest is
 automatically launched.
 

+If you don't know what filesystems a disk image contains, you
+can either run guestfish without this option, then list the partitions
+and LVs available (see L</list-partitions> and L</lvs> commands),
+or you can use the L<virt-list-filesystems(1)> program.
+

 =item B<-n> | B<--no-sync>
 
 Disable autosync.  This is enabled by default.  See the discussion
 =item B<-n> | B<--no-sync>
 
 Disable autosync.  This is enabled by default.  See the discussion


@@ -164,8 +198,12 @@ I<REMOTE CONTROL GUESTFISH OVER A SOCKET> below.
 
 =item B<-r> | B<--ro>
 
 
 =item B<-r> | B<--ro>
 

-This changes the C<-m> option so that mounts are done read-only
-(see C<guestfs_mount_ro> in the L<guestfs(3)> manpage).
+This changes the C<-a> and C<-m> options so that disks are added and
+mounts are done read-only (see L<guestfs(3)/guestfs_mount_ro>).
+
+The option must always be used if the disk image or virtual machine
+might be running, and is generally recommended in cases where you
+don't need write access to the disk.

 
 =item B<--selinux>
 
 
 =item B<--selinux>
 


@@ -250,9 +288,13 @@ quotes.  For example:
  rm '/"'
 
 A few commands require a list of strings to be passed.  For these, use
  rm '/"'
 
 A few commands require a list of strings to be passed.  For these, use

-a space-separated list, enclosed in quotes.  For example:
+a whitespace-separated list, enclosed in quotes.  Strings containing whitespace
+to be passed through must be enclosed in single quotes.  A literal single quote
+must be escaped with a backslash.

 
  vgcreate VG "/dev/sda1 /dev/sdb1"
 
  vgcreate VG "/dev/sda1 /dev/sdb1"

+ command "/bin/echo 'foo      bar'"
+ command "/bin/echo \'foo\'"

 
 =head1 WILDCARDS AND GLOBBING
 
 
 =head1 WILDCARDS AND GLOBBING
 


@@ -346,6 +388,23 @@ it, eg:
 
  echo "~"
 
 
  echo "~"
 

+=head1 WINDOWS PATHS
+
+If a path is prefixed with C<win:> then you can use Windows-style
+paths (with some limitations).  The following commands are equivalent:
+
+ file /WINDOWS/system32/config/system.LOG
+
+ file win:/windows/system32/config/system.log
+
+ file win:\windows\system32\config\system.log
+
+ file WIN:C:\Windows\SYSTEM32\conFIG\SYSTEM.LOG
+
+This syntax implicitly calls C<case-sensitive-path> (q.v.) so it also
+handles case insensitivity like Windows would.  This only works in
+argument positions that expect a path.
+

 =head1 EXIT ON ERROR BEHAVIOUR
 
 By default, guestfish will ignore any errors when in interactive mode
 =head1 EXIT ON ERROR BEHAVIOUR
 
 By default, guestfish will ignore any errors when in interactive mode


@@ -432,6 +491,18 @@ number of megabytes
 
 number of gigabytes
 
 
 number of gigabytes
 

+=item C<nn>T or C<nn>TB
+
+number of terabytes
+
+=item C<nn>P or C<nn>PB
+
+number of petabytes
+
+=item C<nn>E or C<nn>EB
+
+number of exabytes
+

 =item C<nn>sects
 
 number of 512 byte sectors
 =item C<nn>sects
 
 number of 512 byte sectors


@@ -510,6 +581,55 @@ Close and reopen the libguestfs handle.  It is not necessary to use
 this normally, because the handle is closed properly when guestfish
 exits.  However this is occasionally useful for testing.
 
 this normally, because the handle is closed properly when guestfish
 exits.  However this is occasionally useful for testing.
 

+=head2 sparse
+
+ sparse filename size
+
+This creates an empty sparse file of the given size, and then adds
+so it can be further examined.
+
+In all respects it works the same as the C<alloc> command, except that
+the image file is allocated sparsely, which means that disk blocks are
+not assigned to the file until they are needed.  Sparse disk files
+only use space when written to, but they are slower and there is a
+danger you could run out of real disk space during a write operation.
+
+For more advanced image creation, see L<qemu-img(1)> utility.
+
+Size can be specified (where C<nn> means a number):
+
+=over 4
+
+=item C<nn> or C<nn>K or C<nn>KB
+
+number of kilobytes, eg: C<1440> = standard 3.5in floppy
+
+=item C<nn>M or C<nn>MB
+
+number of megabytes
+
+=item C<nn>G or C<nn>GB
+
+number of gigabytes
+
+=item C<nn>T or C<nn>TB
+
+number of terabytes
+
+=item C<nn>P or C<nn>PB
+
+number of petabytes
+
+=item C<nn>E or C<nn>EB
+
+number of exabytes
+
+=item C<nn>sects
+
+number of 512 byte sectors
+
+=back
+

 =head2 time
 
  time command args...
 =head2 time
 
  time command args...


@@ -597,7 +717,13 @@ I<1> if there was an error.
 =head1 SEE ALSO
 
 L<guestfs(3)>,
 =head1 SEE ALSO
 
 L<guestfs(3)>,

-L<http://libguestfs.org/>.
+L<http://libguestfs.org/>,
+L<virt-cat(1)>,
+L<virt-edit(1)>,
+L<virt-list-filesystems(1)>,
+L<virt-ls(1)>,
+L<virt-rescue(1)>,
+L<virt-tar(1)>.

 
 =head1 AUTHORS
 
 
 =head1 AUTHORS