mmv.1

.Dd $Mdocdate: September 24 2023 $
.Dt MMV 1
.Os
.Sh NAME
.Nm mmv ,
.Nm mcp
.Nd mapped file moves and -copies
.Sh SYNOPSIS
.Nm
.Op Fl 0bdeinv
.Ar command
.Op Ar argument ...
.Nm mcp
.Op Fl 0bdeiv
.Ar command
.Op Ar argument ...
.Sh DESCRIPTION
The
.Nm mmv
and
.Nm mcp
utilities are tools for copying-, moving-, and renaming files by mapping
filenames using a provided
.Ar command
and
.Ar argument Ns s.
When invoked, the program specified by
.Ar command
with the arguments
.Ar argument ...
is invoked to read filenames from the standard input and output new filenames to
the standard output.
.Nm mmv
will then move all files — and
.Nm mcp
will then copy all files — that were provided via the standard input to their
coressponding destinations which
.Ar command
printed to the standard output.
In other words,
.Ql mmv cat
can be seen as a no-op.
You can find a variety of examples under the
.Sx EXAMPLES
section.
.Pp
It is also very important to remember that filenames may contain newline
characters.
The
.Fl 0 ,
.Fl e ,
and
.Fl i
options might be of use to help you properly handle these.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl 0 , Fl Fl nul
Treat filenames read from the standard input as being nul-byte
.Pq Sq \e0
separated instead of newline
.Pq Sq \en
separated.
This is useful if input filenames might contain embedded newline characters.
.It Fl b , Fl Fl basename
Only apply the mapping command to the basenames of the given file paths.
This stops you from accidentally mutating directory components, which is not
typically a desired behavior.
If no basename can be derived
.Pq the root directory for example has no basename ,
then a warning diagnostic will be printed to the standard error, and the path
will remain unchanged.
.It Fl d , Fl Fl dry-run
Print the renamings that would take place with the given inputs and arguments to
the standard error without actually executing any moves.
It is recommended you
run
.Nm mmv
and
.Nm mcp
with this flag before performing any changes to ensure nothing unexpected
occurs.
.It Fl e , Fl Fl encode
Encode newlines in filenames as the literal string
.Sq \en
and backslashes as the literal string
.Sq \e\e .
This will allow you to treat multi-line filenames as single-line ones.
An example usecase of this is detailed in the
.Sx EXAMPLES
section.
.It Fl i , Fl Fl individual
Spawn a new instance of the command provided to
.Nm mmv
or
.Nm mcp
for each input filename.
This is useful for use in conjunction with the
.Fl 0
option when provided mapping command doesn’t have built-in support for
nul-byte delimited input.
.It Fl n , Fl Fl no-backup
The default behavior of
.Nm mmv
is to create a backup of your input files in
.Pa $XDG_CACHE_DIR/mmv
to avoid dataloss in the case of an error.
If for whatever reason you do not want to create this directory
.Pq perhaps for performance reasons
then you can use this option.
.Pp
This flag does not apply to
.Nm mcp .
.It Fl v , Fl Fl verbose
Display output to the standard error detailing which files and directories are
being created, moved, and removed.
.El
.Sh FILES
.Bl -tag -width $XDG_CACHE_DIR/mmv
.It Pa $XDG_CACHE_DIR/mmv
The backup directory where a copy of your input files are stored during
operation.
Input files are backed up in a subdirectory whose name is the timestamp of when
the directory was created.
If the
.Ev XDG_CACHE_DIR
environment variable is not set,
.Nm
will default to using
.Pa $HOME/.cache/mmv .
.El
.Sh EXIT STATUS
.Ex -std mmv mcp
.Sh EXAMPLES
Swap the files
.Pa foo
and
.Pa bar :
.Pp
.Dl $ ls foo bar | mmv tac
.Pp
Rename all files in the current directory to use hyphens
.Pq Sq -
instead of spaces:
.Pp
.Dl $ ls | mmv tr \(aq \(aq \(aq-\(aq
.Pp
Rename all *.jpeg files to use the
.Sq .jpg
file extension:
.Pp
.Dl $ ls *.jpeg | mmv sed \(aqs/\e.jpeg$/.jpg/\(aq
.Pp
Rename a given list of movies to use lowercase letters and hyphens instead of
uppercase letters and spaces, and number them so that they’re properly ordered
in globs
.Po
e.g. rename
.Pa The Return of the King.mp4
to
.Pa 02-the-return-of-the-king.mp4
.Pc :
.Pp
.Bd -literal -offset indent
$ ls \(aqThe Fellowship of the Ring.mp4\(aq ... \(aqThe Two Towers.mp4\(aq | \e
	mmv awk \(aq{ gsub(" ", "-"); printf "%02d-%s", NR, tolower($0) }\(aq
.Ed
.Pp
Rename files interactively in your editor while encoding newlines into the
literal string
.Sq \en ,
making use of
.Xr vipe 1
from moreutils:
.Pp
.Dl $ ls | mmv -0e vipe
.Pp
Rename all C source code and header files in a git repository to use snake_case
instead of camelCase using the GNU
.Xr sed 1
.Ql \eL
extension:
.Pp
.Dl $ git ls-files \(aq*.[ch]\(aq | mmv sed \(aqs/[A-Z]/\eL_&/g\(aq
.Pp
Lowercase all filenames within a directory hierarchy which may contain newline
characters:
.Pp
.Dl $ find . -print0 | mmv -0 tr A-Z a-z
.Pp
Map filenames which may contain newlines in the current directory with the
command
.Ql cmd ,
which itself does not support nul-byte separated entries.
This only works assuming your mapping doesn’t require any context outside of the
given input filename
.Po
for example, you would not be able to number your files as this requires
knowledge of the input files position in the input list
.Pc :
.Pp
.Dl $ ls --zero | mmv -0i cmd
.Pp
Uppercase the files in the
.Pa /foo/bar
directory, while leaving the names of
.Pa foo
and
.Pa bar
unchanged:
.Pp
.Dl $ ls /foo/bar/* | mmv -b tr a-z A-Z
.Sh SEE ALSO
.Xr awk 1 ,
.Xr cp 1 ,
.Xr mv 1 ,
.Xr sed 1 ,
.Xr vipe 1
.Pp
.Lk https://thomasvoss.com/prj/mmv "Extended Description and -Documentation"
.Sh AUTHORS
.An Thomas Voss Aq Mt mail@thomasvoss.com