String Pattern-Matching Library Functions         isencrypt(3GEN)



NAME
     isencrypt - determine whether  a  buffer  of  characters  is
     encrypted

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


     #include

     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  charac-
     ters in the buffer.


     isencrypt() assumes that the file is not  encrypted  if  all
     the  characters  in the first block are ASCI characters. If
     there are non-ASCI characters in the first  ninbuf  charac-
     ters,  and  if the setlocale() LCTYPE category is set to C
     or ascii, isencrypt() assumes that the buffer is encrypted


     If the LCTYPE 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.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:











SunOS 5.11          Last change: 29 Dec 1996                    1






String Pattern-Matching Library Functions         isencrypt(3GEN)



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     setlocale(3C), attributes(5)

NOTES
     When compiling multithreaded  applications,  the  RENTRANT
     flag  must be defined on the compile line.  This flag should
     only be used in multithreaded applications.









































SunOS 5.11          Last change: 29 Dec 1996                    2