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)