md5(1)                                                               md5(1)

NAME
     md5 - calculate a checksum in the form of a fake-proof fingerprint

SYNOPSIS
     md5 file ...

     md5 options [file ...]

DESCRIPTION
     Checksums for files can be calculated using the sum or cksum command.
     However, both commands are only suitable for detecting transmission
     errors. The underlying polynom is extremely simple and in particular
     allows files to be modified in such a way that the checksum calculated
     is identical with a previously specified checksum (even if the files
     are different).

     md5 takes as input a specified string or message or file of arbitrary
     length and creates a checksum in the form of a 128-bit fingerprint
     (also termed message digest) as output. To date it has not been possi-
     ble to create two strings with the same fingerprint or one string with
     a prespecified fingerprint. This makes md5 a very safe procedure for
     producing unique digital signatures.

OPTIONS
     The following four options may be used in any combination, except that
     file must be the last object on the command line.

     If no option or file is specified, md5 reads from standard input.

     -s"string"   Outputs the checksum of the specified string.

     -t           Runs a built-in time trial.

     -x           Starts a built-in test suite for comparison with the
                  checksum supplied by the current computer.

     file         Calculates the checksum(s) for the specified file(s).

EXAMPLES
     Example 1:

     Use the following command to create the md5 checksum for the string
     "Siemens Nixdorf":

     Input:

          md5 -s"Siemens Nixdorf"

     Output:

          MD5 ("Siemens Nixdorf") = b89058eb500949a2d16f69baf78cf45d




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md5(1)                                                               md5(1)

     Example 2:

     A typical sample application is to use the checksum of a software
     package. If you want to check the md5 checksum for a software package,
     apply the command to the relevant package and compare the result with
     the value from the package documentation.

     Input:

          md5 SIY3A232+.pkg

     Output:

          MD5 (SIY3A232+.pkg) = 51f0ac1b6d777b6278facde79a901385

SEE ALSO
     cksum(1), sum(1).





































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