systemd-vpick - Man Page

systemd-vpick [Options...] [PATH...]

systemd-vpick resolves a file system path referencing a "​.v/" versioned directory to a path to the newest (by version) file contained therein​. This tool provides a command line interface for the systemd.v(7) logic​.

The tool expects a path to a "​.v/" directory as argument (either directly, or with a triple underscore pattern as final component)​. It then determines the newest file contained in that directory, and writes its path to standard output​.

Unless the triple underscore pattern is passed as last component of the path, it is typically necessary to at least specify the --suffix= switch to configure the file suffix to look for​.

If the specified path does not reference a "​.v/" path (i​.e​. neither the final component ends in "​.v", nor the penultimate does or the final one does contain a triple underscore) its specified path is written unmodified to standard output​.

The following options are understood:

--basename=, -B

Overrides the "basename" of the files to look for, i​.e​. the part to the left of the variable part of the filenames​. Normally this is derived automatically from the filename of the "​.v" component of the specified path, or from the triple underscore pattern in the last component of the specified path​.

Added in version 256​.

-V

Explicitly configures the version to select​. If specified, a filename with the specified version string will be looked for, instead of the newest version available​.

Added in version 256​.

-A

Explicitly configures the architecture to select​. If specified, a filename with the specified architecture identifier will be looked for​. If not specified, only filenames with a locally supported architecture are considered, or those without any architecture identifier​.

Added in version 256​.

--suffix=, -S

Configures the suffix of the filenames to consider​. For the "​.v/" logic it is necessary to specify the suffix to look for, and the "​.v/" component must also carry the suffix immediately before "​.v" in its name​.

Added in version 256​.

--type=, -t

Configures the inode type to look for in the "​.v/" directory​. Takes one of "reg", "dir", "sock", "fifo", "blk", "chr", "lnk" as argument, each identifying an inode type​. See inode(7) for details about inode types​. If this option is used inodes not matching the specified type are filtered and not taken into consideration​.

Added in version 256​.

--print=, -p

Configures what precisely to write to standard output​. If not specified, prints the full, resolved path of the newest matching file in the "​.v/" directory​. This switch can be set to one of the following:

• If set to "filename", will print only the filename instead of the full path of the resolved file​.
• If set to "version", will print only the version of the resolved file​.
• If set to "type", will print only the inode type of the resolved file (i​.e​. a string such as "reg" for regular files, or "dir" for directories)​.
• If set to "arch", will print only the architecture of the resolved file​.
• If set to "tries", will print only the tries left/tries done of the resolved file​.
• If set to "all", will print all of the above in a simple tabular output​.

Added in version 256​.

--resolve=

Takes a boolean argument​. If true the path to the versioned file is fully canonicalized (i​.e​. symlinks resolved, and redundant path components removed) before it is shown​. If false (the default) this is not done, and the path is shown without canonicalization​.

Added in version 256​.

-h,  --help

Print a short help text and exit​.

--version

Print a short version string and exit​.

Use a command like the following to automatically pick the newest raw disk image from a "​.v/" directory:

$ systemd-vpick --suffix=​.raw --type=reg /var/lib/machines/quux​.raw​.v/

This will enumerate all regular files matching /var/lib/machines/quux​.raw​.v/quux*​.raw, filter and sort them according to the rules described in systemd.v(7), and then write the path to the newest (by version) file to standard output​.

Use a command like the following to automatically pick the newest OS directory tree from a "​.v/" directory:

$ systemd-vpick --type=dir /var/lib/machines/waldo​.v/

This will enumerate all directory inodes matching /var/lib/machines/waldo​.v/waldo*, filter and sort them according to the rules described in systemd.v(7), and then write the path to the newest (by version) directory to standard output​.

For further examples see systemd.v(7)​.

On success, 0 is returned, a non-zero failure code otherwise​.

systemd(1), systemd.v(7)

systemd.directives(7), systemd.index(7), systemd.mstack(7), systemd.v(7).