.\" Copyright (c) 2014 Jean-Pierre Andre
.\" This file may be copied under the terms of the GNU Public License.
.\"
.TH NTFSTRUNCATE 8 "June 2014" "ntfs-3g 2022.10.3"
.SH NAME
ntfstruncate \- truncate a file on an NTFS volume
.SH SYNOPSIS
\fBntfstruncate\fR [\fIoptions\fR] \fIdevice\fR \fIfile\fR \fI[attr-type\fR [\fIattr-name\fR]] \fInew-length\fR
.SH DESCRIPTION
.B ntfstruncate
truncates (or extends) a specified attribute belonging to a
file or directory, to a specified length.
.SH OPTIONS
Below is a summary of all the options that
.B ntfstruncate
accepts.  Nearly all options have two equivalent names.  The short name is
preceded by
.B \-
and the long name is preceded by
.BR \-\- .
Any single letter options, that don't take an argument, can be combined into a
single command, e.g.
.B \-fv
is equivalent to
.BR "\-f \-v" .
Long named options can be abbreviated to any unique prefix of their name.
.TP
\fB\-f\fR, \fB\-\-force\fR
This will override some sensible defaults, such as not using a mounted volume.
Use this option with caution.
.TP
\fB\-h\fR, \fB\-\-help\fR
Show a list of options with a brief description of each one.
.TP
\fB\-l\fR
Display licensing information.
.TP
\fB\-n\fR, \fB\-\-no-action\fR
Simulate the truncation without actually write to device.
.TP
\fB\-q\fR, \fB\-\-quiet\fR
Suppress some debug/warning/error messages.
.TP
\fB\-v\fR, \fB\-\-verbose\fR
Display more debug/warning/error messages.
.TP
\fB\-V\fR, \fB\-\-version\fR
Show the version number, copyright and license of
.BR ntfstruncate .
.TP
\fBattr-type\fR
Define a particular attribute type to be truncated (advanced use only).
By default, the unnamed $DATA attribute (the contents of a plain file) will
be truncated. The attribute has to be specified by a number in decimal
or hexadecimal :
.TS
box;
lB lB lB
l l l.
Hex	Decimal	Name
0x10	16	"$STANDARD_INFORMATION"
0x20	32	"$ATTRIBUTE_LIST"
0x30	48	"$FILE_NAME"
0x40	64	"$OBJECT_ID"
0x50	80	"$SECURITY_DESCRIPTOR"
0x60	96	"$VOLUME_NAME"
0x70	112	"$VOLUME_INFORMATION"
0x80	128	"$DATA"
0x90	144	"$INDEX_ROOT"
0xA0	160	"$INDEX_ALLOCATION"
0xB0	176	"$BITMAP"
0xC0	192	"$REPARSE_POINT"
0xD0	208	"$EA_INFORMATION"
0xE0	224	"$EA"
0xF0	240	"$PROPERTY_SET"
0x100	256	"$LOGGED_UTILITY_STREAM"
.TE
.sp
.TP
\fBattr-name\fR
Define the name of the particular attribute type to be truncated
(advanced use only).
.sp
.TP
\fBnew-length\fR
Specify the target size of the file.
It will be rounded up to a multiple of the cluster size.
A suffix of K, M, G, T, P or E may be appended to
mean a multiplicative factor of a power of 1000. Similarly a suffix of
Ki, Mi, Gi, Ti, Pi or Ei may be appended to mean a multiplicative factor
of a power of 1024.
.SH EXAMPLES
Resize to 100MB the file database.db located in the Data directory
which is at the root of an NTFS file system.
.RS
.sp
.B ntfstruncate /dev/sda1 Data/database.db 100M
.sp
.RE
.SH BUGS
There are no known problems with
.BR ntfstruncate .
If you find a bug, please send an email
describing the problem to the development team:
.br
.nh
ntfs\-3g\-devel@lists.sf.net
.hy
.SH AUTHORS
.B ntfstruncate
was written by Anton Altaparmakov.
.SH AVAILABILITY
.B ntfstruncate
is part of the
.B ntfs-3g
package and is available from:
.br
.nh
https://github.com/tuxera/ntfs-3g/wiki/
.hy
.SH SEE ALSO
.BR ntfs-3g (8),
.BR ntfsfallocate (8),
.BR ntfsprogs (8).