mirror of
https://github.com/lcn2/calc.git
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b30c5c1855
Drop support for CLOCK_SGI_CYCLE.
Improved seed() generation. Improved some comments in seed.c.
Added have_environ.c to build have_environ.h in order to
determine if:
extern char **environ; /* user environment */
is an valid external symbol.
68 lines
2.1 KiB
Plaintext
68 lines
2.1 KiB
Plaintext
NAME
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seed - return a value that may be used to seed a pseudo-random generator
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SYNOPSIS
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seed()
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TYPES
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return integer
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DESCRIPTION
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Generate a pseudo-random seed based on a collection of system and process
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information. The seed() builtin function returns a value:
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0 <= seed < 2^64
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IMPORTANT WARNING:
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It should be pointed out that the information collected by seed
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is almost certainly non-chaotic. This function is likely not
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suitable for applications (such as cryptographic applications)
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where the unpredictability of seeds is critical.
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Given the above warning, this builtin function produces a seed that is
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suitable for most applications that desire a different pseudo-random
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sequence each time they are run.
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The return value of this builtin function should NOT be considered
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a random or pseudo-random value. The return value could be used
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as an argument to seed functions such as srand() or srandom().
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EXAMPLE
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; print srand(seed())
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RAND state
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; print srandom(seed())
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RAND state
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LIMITS
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none
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LINK LIBRARY
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NUMBER *pseudo_seed(void)
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SEE ALSO
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seed, srand, randbit, isrand, rand, random, srandom, israndom
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## Copyright (C) 1999,2018,2021 Landon Curt Noll
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##
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## Calc is open software; you can redistribute it and/or modify it under
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## the terms of the version 2.1 of the GNU Lesser General Public License
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## as published by the Free Software Foundation.
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##
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## Calc is distributed in the hope that it will be useful, but WITHOUT
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## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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## Public License for more details.
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##
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## A copy of version 2.1 of the GNU Lesser General Public License is
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## distributed with calc under the filename COPYING-LGPL. You should have
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## received a copy with calc; if not, write to Free Software Foundation, Inc.
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## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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##
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## Under source code control: 1999/10/03 10:04:29
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## File existed as early as: 1999
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##
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## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
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## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
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