cksum,md5sum,sum - print file checksum and block count

sum lists the checksum, and for most methods the block count, for each file argument. The standard input is read if there are no file arguments. getconf UNIVERSE determines the default sum method: att for the att universe, bsd otherwise. The default for the other commands is the command name itself. The att method is a true sum, all others are order dependent.

Method names consist of a leading identifier and 0 or more options separated by -.

getconf PATH_RESOLVE determines how symbolic links are handled. This can be explicitly overridden by the --logical, --metaphysical, and --physical options below. PATH_RESOLVE can be one of:

logical

Follow all symbolic links.

metaphysical

Follow command argument symbolic links, otherwise don't follow.

physical

Don't follow symbolic links.

-a, --all

List the checksum for all files. Use with --total to list both individual and total checksums and block counts.

-b, --binary

Read files in binary mode. This is the default.

-B, --scale=scale

Block count scale (bytes per block) override for methods that include size in the output. The default is method specific.

-c, --check

Each file is interpreted as the output from a previous sum. If --header or --permissions was specified in the previous sum then the checksum method is automatically determined, otherwise --method must be specified. The listed checksum is compared with the current value and a warning is issued for each file that does not match. If file was generated by --permissions then the file mode, user and group are also checked. Empty lines, lines starting with #<space>, or the line # are ignored. Lines containing no blanks are interpreted as [no]name[=value ] options:

method=name

Checksum method to apply to subsequent lines.

permissions

Subsequent lines were generated with --permissions.

-h, --header

Print the checksum method as the first output line. Used with --check and --permissions .

-l, --list

Each file is interpreted as a list of files, one per line, that is checksummed.

-p, --permissions

If --check is not specified then list the file mode, user and group between the checksum and path. User and group matching the caller are output as -. If --check is specified then the mode, user and group for each path in file are updated if necessary to match those in file. A warning is printed on the standard error for each changed file.

-R, --recursive

Recursively checksum the contents of directories.

-S, --silent|status

No output for --check; 0 exit status means all sums matched, non-0 means at least one sum failed to match. Ignored for --permissions.

-t, --total

List only the total checksum and block count of all files. --all --total lists each checksum and the total. The total checksum and block count may be different from the checksum and block count of the catenation of all files due to partial blocks that may occur when the files are treated separately.

-T, --text

Read files in text mode (i.e., treat \r\n as \n).

-w, --warn

Warn about invalid --check lines. On by default; -w means --nowarn.

-x, --method|algorithm=method

Specifies the checksum method to apply. Parenthesized method options are readonly implementation details.

att|sys5|s5|default

The system 5 release 4 checksum. This is the default for sum when getconf UNIVERSE is att. This is the only true sum; all of the other methods are order dependent.

ast4|32x4|tw

The ast 128 bit PRNG hash generated by catenating 4 separate 32 bit PNRG hashes. The block count is not printed.

bsd|ucb

The BSD checksum.

crc

32 bit CRC (cyclic redundancy check).

polynomial=mask

The 32 bit crc polynomial bitmask with implicit bit 32. The default value is 0xedb88320.

done[=number]

XOR the final crc value with number. 0xffffffff is used if number is omitted. The option value may be omitted. The default value is 0.

init[=number]

The initial crc value. 0xffffffff is used if number is omitted. The option value may be omitted. The default value is 0.

rotate

XOR each input character with the high order crc byte (instead of the low order).

size[=number]

Include the total number of bytes in the crc. number, if specified, is first XOR'd into the size. The option value may be omitted. The default value is 0.

prng

32 bit PRNG (pseudo random number generator) hash.

mpy=number

The 32 bit PRNG multiplier. The default value is 0x01000193.

add=number

The 32 bit PRNG addend. The default value is 0.

init[=number]

The PRNG initial value. 0xffffffff is used if number is omitted. The option value may be omitted. The default value is 0x811c9dc5.

md5|MD5

The RSA Data Security, Inc. MD5 Message-Digest Method, 1991-2, used with permission. The block count is not printed.

(version)

md5 (RSA Data Security, Inc. MD5 Message-Digest, 1991-2) 1996-02-29

sha1|SHA1|sha-1|SHA-1

FIPS 180-1 SHA-1 secure hash algorithm 1.

(version)

sha1 (FIPS 180-1) 1996-09-26

(author)

Steve Reid <steve@edmweb.com>

sha256|sha-256|SHA256|SHA-256

FIPS SHA-256 secure hash algorithm.

(version)

sha-256 (FIPS) 2000-01-01

(author)

Aaron D. Gifford

sha384|sha-384|SHA384|SHA-384

FIPS SHA-384 secure hash algorithm.

(version)

sha-384 (FIPS) 2000-01-01

(author)

Aaron D. Gifford

sha512|sha-512|SHA512|SHA-512

FIPS SHA-512 secure hash algorithm.

(version)

sha-512 (FIPS) 2000-01-01

(author)

Aaron D. Gifford

posix|cksum|std|standard

The posix 1003.2-1992 32 bit crc checksum. This is the default cksum(1) method. Shorthand for crc-0x04c11db7-rotate-done-size .

zip

The zip(1) crc. Shorthand for crc-0xedb88320-init-done .

fddi

The FDDI crc. Shorthand for crc-0xedb88320-size=0xcc55cc55.

fnv|fnv1

The Fowler-Noll-Vo 32 bit PRNG hash with non-zero initializer (FNV-1). Shorthand for prng-0x01000193-init=0x811c9dc5.

ast|strsum

The ast strsum(3) PRNG hash. Shorthand for prng-0x63c63cd9-add=0x9c39c33d.

-L, --logical|follow

Follow symbolic links when traversing directories. The default is determined by getconf PATH_RESOLVE.

-H, --metaphysical

Follow command argument symbolic links, otherwise don't follow symbolic links when traversing directories. The default is determined by getconf PATH_RESOLVE.

-P, --physical

Don't follow symbolic links when traversing directories. The default is determined by getconf PATH_RESOLVE.

-r, --bsd

Equivalent to --method=bsd --scale=512 for compatibility with other sum(1) implementations.

-s, --sysv

Equivalent to --method=sys5 for compatibility with other sum(1) implementations.

getconf(1), tw(1), uuencode(1)

version

sum (AT&T Research) 2012-04-20

author

Glenn Fowler <gsf@research.att.com>

author

David Korn <dgk@research.att.com>

copyright

Copyright © 1992-2012 AT&T Intellectual Property

license

http://www.eclipse.org/org/documents/epl-v10.html