isencrypt(3G)                    UNIX System V                    isencrypt(3G)


NAME
      isencrypt - determine whether a character buffer is encrypted

SYNOPSIS
      cc [flag ...] file ...  -lgen [library ...]

      #include <libgen.h>

      int isencrypt (const char *fbuf, sizet ninbuf);

DESCRIPTION
      isencrypt uses heuristics to determine whether a buffer of characters is
      encrypted.  It requires two arguments: a pointer to an array of
      characters and the number of characters in the buffer.

      isencrypt assumes that the file is not encrypted if all the characters in
      the first block are ASCII characters.  If there are non-ASCII characters
      in the first ninbuf characters, isencrypt assumes that the buffer is
      encrypted if the setlocale LCCTYPE category is set to C or ascii.

      If the LCCTYPE category is set to a value other than C or ascii, then
      isencrypt uses a combination of heuristics to determine if the buffer is
      encrypted.  If ninbuf has at least 64 characters, a chi-square test is
      used to determine if the bytes in the buffer have a uniform distribution;
      and isencrypt assumes the buffer is encrypted if it does.  If the buffer
      has less than 64 characters, a check is made for null characters and a
      terminating new-line to determine whether the buffer is encrypted.

DIAGNOSTICS
      If the buffer is encrypted, 1 is returned; otherwise zero is returned.

SEE ALSO
      setlocale(3C).





















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