isencrypt(3G)                    DG/UX 5.4.2                   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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