cksfv - tests and creates simple file verification (SFV) listings
cksfv [-bciqrL] [-C dir] [-f file] [-g path] [file ...]
is a tool for verifying CRC32 checksums of files. CRC32 checksums
are used to verify that files are not corrupted. The algorithm is
cryptographically crippled so it can not be used for security purposes.
(1) or sha1sum
(1) are much better tools for checksuming
files. cksfv should only be used for compatibility with other systems.
cksfv has two operation modes: checksum creation and checksum verification
In checksum creation mode
cksfv outputs CRC32 checksums of
files to to stdout, normally redirected to an .sfv file.
In checksum verification mode
cksfv reads filenames from an
sfv file, and compares the recorded checksum values against recomputed
checksums of files.
These options are available
- Strip dirnames from filenames that are checksumed. loads
the files from original positions, but prints only basenames to catalogue
in sfv file.
- Use stdout for printing progress and final resolution
(files OK or some errors detected). This is useful for external programs
analysing output of cksfv. This also forces fflushes on the output when
- -C dir
- Change current directory before proceeding with a
verification operation. This option is mostly obsoleted with -g option.
Earlier this was used to verify checksums in a different directory: cksfv
-C foo -f foo/bar.sfv
- -f file
- Verify checksums in the sfv file
- -g file
- Change current directory to the path name of the file and
verify checksums in the sfv.
- Ignore case in filenames. This is used in the checksum
- Follow symlinks when recursing subdirectories. This option
is used with the -r option.
- Enable QUIET mode (instead of verbose mode), only error
messages are printed
- Enable VERBOSE mode, this is the default mode
- recurse directories and check the .sfv files in each.
Symlinks are not followed by default. This option cannot be used with -f
and -g options.
Verify checksums of files listed in 'foo/files.sfv':
cksfv -g foo/files.sfv
Create checksums for a set of files:
cksfv *.gz > files.sfv
Verify checksums of case-insensitive filenames listed in 'files.sfv'.
This is sometimes useful with files created by operating systems
that have case-insensitive filesystem names.
cksfv -i -g files.sfv
Check checksums of files 'foo' and 'bar' listed in 'files.sfv':
cksfv -g files.sfv foo bar
Create checksums of files matching /foo/bar/* and strip dirnames away:
cksfv -b /foo/bar/* > files.sfv
Recursively scan /foo/bar and verify each .sfv file:
cksfv -C /foo/bar -r
Same as previous, but starting from the current working directory
and also following symlinks during recursion:
cksfv -r -L
This manual page was originally written by Stefan Alfredsson
<firstname.lastname@example.org>. It was later modified by Heikki Orsila
<email@example.com> and Durk van Veen