isencrypt(3GEN) 				     String Pattern-Matching Library Functions					   isencrypt(3GEN)

NAME

       isencrypt - determine whether a buffer of characters is encrypted

SYNOPSIS

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

       #include<libgen.h>

       int isencrypt(const char *fbuf, size_t 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, and if the setlocale() LC_CTYPE category is set to C or ascii, isencrypt() assumes that the buf-
       fer is encrypted

       If the LC_CTYPE 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; if it does, then isencrypt() assumes the buffer is encrypted.  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.

RETURN VALUES

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

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       setlocale(3C), attributes(5)

NOTES

       When  compiling multithreaded applications, the _REENTRANT flag must be defined on the compile line.  This flag should only be used in mul-
       tithreaded applications.

SunOS 5.11							    29 Dec 1996 						   isencrypt(3GEN)