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author | Pádraig Brady <P@draigBrady.com> | 2015-02-09 20:58:47 +0000 |
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committer | Pádraig Brady <P@draigBrady.com> | 2015-02-11 00:31:39 +0000 |
commit | 430bda373361addf16962301b3afaf1b19ee9fc8 (patch) | |
tree | a7ce3cade74f55cd6f6d069535aa0a641f0ab60c | |
parent | 99f76aec8a7e74f2e1622b74b1011fac6f677f4e (diff) | |
download | coreutils-430bda373361addf16962301b3afaf1b19ee9fc8.tar.xz |
doc: give an example of using a seed for random operations
* doc/coreutils.texi (Random sources): Give an example using openssl,
generating a reproducible arbitrary amount of randomly distributed
data, given a seed value.
-rw-r--r-- | doc/coreutils.texi | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 87fb3dcb7..bb652aca5 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -1240,6 +1240,21 @@ operating system. To reproduce the results of an earlier invocation of a command, you can save some random data into a file and then use that file as the random source in earlier and later invocations of the command. +@cindex random seed +Rather than depending on a file, one can generate a reproducible +arbitrary amount of pseudo-random data given a seed value, using +for example: + +@example +get_seeded_random() +@{ + seed="$1" + openssl enc -aes-256-ctr -pass pass:"$seed" -nosalt \ + </dev/zero 2>/dev/null +@} + +shuf -i1-100 --random-source=<(get_seeded_random 42) +@end example @node Target directory @section Target directory |