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Create emptyache daemon disk imagespping.
English type: textblock
Cache daemon disk mapping.
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There is also a macro C<commandv(out,err,argv)> which calls C<commandvf> with C<flags=0>.
 
Function C<daemon/command.c:commandrvf>
 
int
commandrvf (char **stdoutput, char **stderror, unsigned flags,
char const* const *argv)

 
This is a more sane version of L<system(3)> for running external commands. It uses fork/execvp, so we don't need to worry about quoting of parameters, and it allows us to capture any error messages in a buffer.
 
If C<stdoutput> is not C<NULL>, then C<*stdoutput> will return the stdout of the command as a string.
 
If C<stderror> is not C<NULL>, then C<*stderror> will return the stderr of the command. If there is a final \n character, it is removed so you can use the error string directly in a call to C<reply_with_error>.
 
Flags are:
 
C<COMMAND_FLAG_FOLD_STDOUT_ON_STDERR>
 
For broken external commands that send error messages to stdout (hello, parted) but that don't have any useful stdout information, use this flag to capture the error messages in the C<*stderror> buffer. If using this flag, you should pass C<stdoutput=NULL> because nothing could ever be captured in that buffer.
 
C<COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN>
 
For running external commands on chrooted files correctly (see L<https://bugzilla.redhat.com/579608>) specifying this flag causes another process to be forked which chroots into sysroot and just copies the input file to stdin of the specified command. The file descriptor is ORed with the flags, and that file descriptor is always closed by this function. See F<daemon/hexdump.c> for an example of usage.
 
There is also a macro C<commandrv(out,err,argv)> which calls C<commandrvf> with C<flags=0>.
 
File F<daemon/device-name-translation.c>
 
Function C<daemon/device-name-translation.c:device_name_translation_init>
 
void
device_name_translation_init (void)

 
Cache daemon disk mapping.
Create empty disk images
When the daemon starts up, populate a cache with the contents of /dev/disk/by-path. It's easiest to use C<ls -lv> here since the names are sorted awkwardly.
 
Function C<daemon/device-name-translation.c:device_name_translation>
 
char *
device_name_translation (const char *device)

 
Perform device name translation.
 
Libguestfs defines a few standard formats for device names. (see also L<guestfs(3)/BLOCK DEVICE NAMING> and L<guestfs(3)/guestfs_canonical_device_name>). They are:
 
F</dev/sdX[N]>
 
F</dev/hdX[N]>
 
F</dev/vdX[N]>
 
These mean the Nth partition on the Xth device. Because Linux no longer enumerates devices in the order they are passed to qemu, we must translate these by looking up the actual device using /dev/disk/by-path/
 
F</dev/mdX>
 
F</dev/VG/LV>
B<--lvm=/dev/I<VG>/I<LV>>
F</dev/mapper/...>
 
F</dev/dm-N>
 
These are not translated here.
 
It returns a newly allocated string which the caller must free.
 

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5265376 String information

Source string description
type: textblock
Source string location
../docs/internal-documentation.pod:3601
String age
4 years ago
Last updated
a year ago
Source string age
4 years ago
Translation file
po-docs/en_GB.po, string 6973