[
Table Of Contents
| Index
]
sum(n) 1.1.0 "sum"
sum - calculate a sum(1) compatible checksum
package require Tcl 8.2
package require sum ?1.1.0?
This package provides a Tcl-only implementation of the sum(1) command
which calculates a 16 bit checksum value from the input data. The BSD
sum algorithm is used by default but the SysV algorithm is also
available.
- ::crc::sum ?-bsd | -sysv? ?-format fmt? ?-chunksize size? [ -filename file | -channel chan | string ]
-
The command takes string data or a file name or a channel and returns
a checksum value calculated using the sum(1) algorithm. The
result is formatted using the format(n) specifier provided or as
an unsigned integer (%u) by default.
- -sysv
-
The SysV algorithm is fairly naive. The byte values are summed and any
overflow is discarded. The lowest 16 bits are returned as the
checksum. Input with the same content but different ordering will
give the same result.
- -bsd
-
This algorithm is similar to the SysV version but includes a bit rotation
step which provides a dependency on the order of the data values.
- -filename name
-
Return a checksum for the file contents instead of for parameter data.
- -channel chan
-
Return a checksum for the contents of the specified channel. The
channel must be open for reading and should be configured for binary
translation. The channel will no be closed on completion.
- -chunksize size
-
Set the block size used when reading data from either files or
channels. This value defaults to 4096.
- -format string
-
Return the checksum using an alternative format template.
| |
% crc::sum "Hello, World!"
37287
|
| |
% crc::sum -format 0x%X "Hello, World!"
0x91A7
|
| |
% crc::sum -file sum.tcl
13392
|
Pat Thoyts
cksum(n) , crc32(n) , sum(1)
checksum , cksum , crc , crc32 , cyclic redundancy check , data integrity , security , sum
Copyright © 2002, Pat Thoyts <[email protected]>