f

Lists or filters file system objects (eg files)

Description

f lists or filters lists of file system objects, such as files, directories, etc. f provides a quick way to output file system items that confirm to specific criteria.

You define this criteria by using +flags (eg +s for all symlinks) and optionally then restricting that criteria with -flags (eg -x to remove all executable items). All flags supported as + are also supported as a -.

By default f will return no results. You need to include +flags.

Output is a JSON array as this format preserves whitespace in file names.

Usage

f options -> <stdout>

<stdin> -> f options -> <stdout>

Examples

Return only directories:

f +d

Return file and directories but exclude symlinks:

f +fd -s

Filter out files in a list (eg created by g) using conditions set by f:

g '*.go' -> f +f

rx '\.(txt|md)' -> f +fw

Flags

• + include files (pair this with any other flag apart from -)
• - exclude files (pair this with any other flag apart from +)
• ? deprecated -- use i instead
• D regular directories
• E other read permissions
• F regular files (exc symlinks, devices, sockets, named pipes, etc)
• Q other write permissions
• R user read permissions
• S sockets
• W user write permissions
• X user execute permissions
• Z other execute permissions
• b block devices
• c character devices
• d all directories (inc symlinks)
• e group read permissions
• f all files (inc symlinks, devices, sockets, name pipes, etc)
• i irregular files (nothing else is known about these files)
• l symlinks
• p POSIX named pipes (FIFO)
• q group write permissions
• r read permissions (user, group, or other)
• s symlinks
• w write permissions (user, group, or other)
• x execute permissions (user, group, or other)
• z group execute permissions

Detail

+ flags are always matched first. Then the - flags are used to filter out any matches from the + flags.

See Also

• g: Glob pattern matching for file system objects (eg *.txt)
• json: JavaScript Object Notation (JSON)
• rx: Regexp pattern matching for file system objects (eg .*\\.txt)

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This document was generated from builtins/core/io/f_doc.yaml.