cs.fstags 20200717.1

Simple filesystem based file tagging and the associated `fstags` command line script.

Simple filesystem based file tagging and the associated fstags command line script.

Latest release 20200717.1: Add the manual page MarkDown source files. Note: well out of date, need updating.

Many basic tasks can be performed with the fstags command line utility, documented under the FSTagsCommand class below.

Why fstags? By storing the tags in a separate file we:

• can store tags without modifying a file
• do not need to know the file's format, or even whether that format supports metadata
• can process tags on any kind of file
• because tags are inherited from parent directories, tags can be automatically acquired merely by arranging your file tree

Tags are stored in the file .fstags in each directory; there is a line for each entry in the directory with tags consisting of the directory entry name and the associated tags.

Tags may be "bare", or have a value. If there is a value it is expressed with an equals ('=') followed by the JSON encoding of the value.

The tags for a file are the union of its direct tags and all relevant ancestor tags, with priority given to tags closer to the file.

For example, a media file for a television episode with the pathname /path/to/series-name/season-02/episode-name--s02e03--something.mp4 might have the tags:

series_title="Series Full Name"
season=2
sf
episode=3
episode_title="Full Episode Title"

obtained from the following .fstags entries:

• tag file /path/to/.fstags: series-name sf series_title="Series Full Name"
• tag file /path/to/series-name/.fstags: season-02 season=2
• tag file /path/to/series-name/season-02/.fstags: episode-name--s02e03--something.mp4 episode=3 episode_title="Full Episode Title"

fstags Examples

Backing up a media tree too big for the removable drives

Walk the media tree for files tagged for backup to archive2:

find /path/to/media backup=archive2

Walk the media tree for files not assigned to a backup archive:

find /path/to/media -backup

Backup the archive2 files using rsync:

fstags find --for-rsync /path/to/media backup=archive2         | rsync -ia --include-from=- /path/to/media /path/to/backup_archive2

Class CascadeRule

A cascade rule of possible source tag names to provide a target tag.

Class FSTags(cs.resources.MultiOpenMixin)

A class to examine filesystem tags.

Class FSTagsCommand(cs.cmdutils.BaseCommand,cs.tagset.TagsCommandMixin)

fstags main command line utility.

Command line usage:

Usage: FSTagsCommand subcommand [...]
  Subcommands:
    autotag paths...
      Tag paths based on rules from the rc file.
    cp [-finv] srcpath dstpath, cp [-finv] srcpaths... dstdirpath
      POSIX cp(1) equivalent, but also copying tags:
      copy files and their tags into targetdir.
      -f  Force: remove destination if it exists.
      -i  Interactive: fail if the destination exists.
      -n  No remove: fail if the destination exists.
      -v  Verbose: show copied files.
    edit [-d] [path]
      Edit the direct tagsets of path, default: '.'
      If path is a directory, provide the tags of its entries.
      Otherwise edit just the tags for path.
      -d          Treat directories like files: edit just its tags.
    export [-a] [--direct] path {tag[=value]|-tag}...
      Export tags for files from path matching all the constraints.
      -a        Export all paths, not just those with tags.
      --direct  Export the direct tags instead of the computed tags.
      The output is in the same CSV format as that from "sqltags export",
      with the following columns:
      * unixtime: the file's st_mtime from os.stat.
      * id: empty
      * name: the file path
      * tags: the file's direct or indirect tags
    find [--direct] [--for-rsync] [-o output_format] path {tag[=value]|-tag}...
      List files from path matching all the constraints.
      --direct    Use direct tags instead of all tags.
      --for-rsync Instead of listing matching paths, emit a
                  sequence of rsync(1) patterns suitable for use with
                  --include-from in order to do a selective rsync of the
                  matched paths.
      -o output_format
                  Use output_format as a Python format string to lay out
                  the listing.
                  Default: {filepath.pathname}
    help [subcommand-names...]
      Print the help for the named subcommands,
      or for all subcommands if no names are specified.
    import {-|srcpath}...
      Import CSV data in the format emitted by "export".
      Each argument is a file path or "-", indicating standard input.
    json_import --prefix=tag_prefix {-|path} {-|tags.json}
      Apply JSON data to path.
      A path named "-" indicates that paths should be read from
      the standard input.
      The JSON tag data come from the file "tags.json"; the name
      "-" indicates that the JSON data should be read from the
      standard input.
    ln [-finv] srcpath dstpath, ln [-finv] srcpaths... dstdirpath
      POSIX ln(1) equivalent, but also copying the tags:
      link files and their tags into targetdir.
      -f  Force: remove destination if it exists.
      -i  Interactive: fail if the destination exists.
      -n  No remove: fail if the destination exists.
      -v  Verbose: show linked files.
    ls [-d] [--direct] [-o output_format] [paths...]
      List files from paths and their tags.
      -d          Treat directories like files, do not recurse.
      --direct    List direct tags instead of all tags.
      -o output_format
                  Use output_format as a Python format string to lay out
                  the listing.
                  Default: {filepath.encoded} {tags}
    mv [-finv] srcpath dstpath, mv [-finv] srcpaths... dstdirpath
      POSIX mv(1) equivalent, but also copying the tags:
      move files and their tags into targetdir.
      -f  Force: remove destination if it exists.
      -i  Interactive: fail if the destination exists.
      -n  No remove: fail if the destination exists.
      -v  Verbose: show moved files.
    ns [-d] [--direct] [paths...]
      Report on the available primary namespace fields for formatting.
      Note that because the namespace used for formatting has
      inferred field names there are also unshown secondary field
      names available in format strings.
      -d          Treat directories like files, do not recurse.
      --direct    List direct tags instead of all tags.
    ont [subcommand [args...]]
      With no arguments, locate the ontology.
      Subcommands:
        tags tag[=value]...
          Query ontology information for the specified tags.
    rename -n newbasename_format paths...
      Rename paths according to a format string.
      -n newbasename_format
          Use newbasename_format as a Python format string to
          compute the new basename for each path.
    scrub paths...
      Remove all tags for missing paths.
      If a path is a directory, scrub the immediate paths in the directory.
    tag {-|path} {tag[=value]|-tag}...
      Tag a path with multiple tags.
      With the form "-tag", remove that tag from the direct tags.
      A path named "-" indicates that paths should be read from the
      standard input.
    tagfile tagfile_path [subcommand ...]
      Subcommands:
        tag tagset_name {tag[=value]|-tag}...
          Directly modify tag_name within the tag file tagfile_path.
    tagpaths {tag[=value]|-tag} {-|paths...}
      Tag multiple paths.
      With the form "-tag", remove the tag from the immediate tags.
      A single path named "-" indicates that paths should be read
      from the standard input.
    test [--direct] path {tag[=value]|-tag}...
      Test whether the path matches all the constraints.
      --direct    Use direct tags instead of all tags.
    xattr_export {-|paths...}
      Import tag information from extended attributes.
    xattr_import {-|paths...}
      Update extended attributes from tags.

Class FSTagsConfig

A configuration for fstags.

Method FSTagsConfig.__init__(self, rcfilepath=None)

Initialise the config.

Parameters:

• rcfilepath: the path to the confguration file If None, default to '~/.fstagsrc' (from RCFILE).

Function get_xattr_value(filepath, xattr_name)

Read the extended attribute xattr_name of filepath. Return the extended attribute value as a string, or None if the attribute does not exist.

Parameters:

• filepath: the filesystem path to update
• xattr_name: the extended attribute to obtain if this is a str, the attribute is the UTF-8 encoding of that name.

Class HasFSTagsMixin

Mixin providing a .fstags property.

Function main(argv=None)

Command line mode.

Class RegexpTagRule

A regular expression based Tag rule.

Function rfilepaths(path, name_selector=None, U=None)

Generator yielding pathnames of files found under path.

Function rpaths(path, *, yield_dirs=False, name_selector=None, U=None)

Recurse over path, yielding (is_dir,subpath) for all selected subpaths.

Function rsync_patterns(paths, top_path)

Return a list of rsync include lines suitable for use with the --include-from option.

Class TagFile(cs.obj.SingletonMixin)

A reference to a specific file containing tags.

This manages a mapping of name => TagSet, itself a mapping of tag name => tag value.

Class TagFileEntry(TagFileEntry,builtins.tuple)

An entry withing a TagFile.

Attributes:

• name: the name of the TagSet entry within tagfile
• tagfile: the TagFile containing name

Class TaggedPath(HasFSTagsMixin,cs.lex.FormatableMixin)

Class to manipulate the tags for a specific path.

Function update_xattr_value(filepath, xattr_name, new_xattr_value)

Update the extended attributes of filepath with new_xattr_value for xattr_name. Return the previous value, or None if the attribute was missing.

We avoid calling os.setxattr if the value will not change.

Parameters:

• filepath: the filesystem path to update
• xattr_name: the extended attribute to update; if this is a str, the attribute is the UTF-8 encoding of that name.
• new_xattr_value: the new extended attribute value, a str which should be the transcription of TagSet i.e. str(tagset)

Function verbose(msg, *a)

Emit message if in verbose mode.

Release Log

Release 20200717.1: Add the manual page MarkDown source files. Note: well out of date, need updating.

Release 20200717: DISTINFO: require cs.obj>=20200716 for SingletonMixin API change.

Release 20200716:

• Update for changed cs.obj.SingletonMixin API.
• fstags: new "export" and "import" subcommands roughly paralleling those from "sqltags", providing CSV formatted export/import.
• fstags export: ew -a (all paths) option - the default is not to not export paths with no tags.

Release 20200521.1: fix DISTINFO.install_requires

Release 20200521:

• Add -i option to cp,ln,mv for command line compatibility, just disables -f.
• New "rename" subcommand to rename files according to a format string.
• Ontology support (optional).
• Various classes are now singletons to avoid dissonance.
• Fold "edittags" subcommand into "edit" via the "-d" (directories like files) option.
• New "ns" subcommand reporting on the primary names available for formatting.
• Accept [clausename]entryname as a format string to obtain the string from that entry of the config file.
• Many bugfixes and improvements.

Release 20200229:

• New TaggedPath.modified property aliasing the TagSet.modified attribute.
• ls: new -d option to treat directories like files (do not recurse), aiding reporting of tags for a directory.
• find,ls subcommands: work off the realpath of the supplied top level path.
• Tag: now subclasses namedtuple.
• Rewrite rpaths() to use scandir and to also yield (is_dir,path) tuples.
• TagSet, Tag, TagChoice moved into new cs.tagset module for reuse.
• json_import: make --prefix mandatory, is "." as separator if not empty.
• Move filename regexp rules to [filename_rules] config section.
• New CascadeRule for representing a "target_tag_name = tag_name1 tag_name2..." config rules.
• autotag: include the cascade rules in the autotagging after the filename rules.

Release 20200210:

• New "json_import" subcommand to import a JSON dict as tags, initial use case to load the metadata from youtube-dl.
• New "scrub" command line operation, to purge tags of paths which do not exist.
• New "cp", "ln" and "mv" subcommands to copy/link/move paths and take their tags with them.
• New "test" subcommand to test paths against tag criteria, useful for find and scripts.
• Small bugfixes.

Release 20200130:

• New FSTagsConfig class which parses the .fstagsrc as a .ini file; related adjustments.
• New HasFSTagsMixin presenting a settable .fstags property with a shared default.
• New xattr_import and xattr_export subcommands, remove implicit xattr access/update from other operations.
• New TagSet.len returning the number of tags.
• Add "-" support for stdin to "tag" and "tagpaths" subcommands.

Release 20200113.2: FSTagsCommand docstring tweak.

Release 20200113.1: Small docstring updates.

Release 20200113: Mirror tags to user.cs.fstags xattr to honour Linux namespace requirements. Add "filesize" to available tag string format (-o option). Small bugfixes.

Release 20191230:

• Command line: new "find" command to search a file tree based on tags.
• Command line: new "mv" command to move a file and its tags.
• Command line: Python string formats for "find" and "ls" output.
• TaggedPath.autotag: new optional no_save parameter, default False, to suppress update of the associated .fstags file.
• Inital and untested "mirror tags to xattrs" support.

Release 20191201: New "edit" subcommand to rename files and edit tags.

Release 20191130.1: Initial release: fstags, filesystem based tagging utility.