1isencrypt(3GEN)    String Pattern-Matching Library Functions   isencrypt(3GEN)
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NAME

6       isencrypt - determine whether a buffer of characters is encrypted
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SYNOPSIS

9       cc  [flag]... [file]... -lgen [library]...
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12       #include<libgen.h>
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14       int isencrypt(const char *fbuf, size_t ninbuf);
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DESCRIPTION

18       isencrypt() uses heuristics to determine whether a buffer of characters
19       is encrypted. It requires two arguments: a pointer to an array of char‐
20       acters and the number of characters in the buffer.
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23       isencrypt()  assumes  that the file is not encrypted if all the charac‐
24       ters in the first block are ASCII characters. If  there  are  non-ASCII
25       characters  in  the  first  ninbuf  characters,  and if the setlocale()
26       LC_CTYPE category is set to C or ascii, isencrypt()  assumes  that  the
27       buffer is encrypted
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30       If  the LC_CTYPE category is set to a value other than C or ascii, then
31       isencrypt() uses a combination of heuristics to determine if the buffer
32       is  encrypted.  If ninbuf has at least 64 characters, a chi-square test
33       is used to determine if the bytes in the buffer have a uniform  distri‐
34       bution;  if  it does, then isencrypt() assumes the buffer is encrypted.
35       If the buffer has less than 64 characters, a check  is  made  for  null
36       characters  and a terminating  new-line to determine whether the buffer
37       is encrypted.
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RETURN VALUES

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

44       See attributes(5) for descriptions of the following attributes:
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49       ┌─────────────────────────────┬─────────────────────────────┐
50       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
51       ├─────────────────────────────┼─────────────────────────────┤
52       │MT-Level                     │MT-Safe                      │
53       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

56       setlocale(3C), attributes(5)
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NOTES

59       When  compiling multithreaded applications, the _REENTRANT flag must be
60       defined on the compile line.  This flag should only be used  in  multi‐
61       threaded applications.
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65SunOS 5.11                        29 Dec 1996                  isencrypt(3GEN)