diff options
Diffstat (limited to 'lib/libc/stdlib/random.3')
| -rw-r--r-- | lib/libc/stdlib/random.3 | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/lib/libc/stdlib/random.3 b/lib/libc/stdlib/random.3 index d1b8208..dd85711 100644 --- a/lib/libc/stdlib/random.3 +++ b/lib/libc/stdlib/random.3 @@ -82,15 +82,8 @@ are usable. For example, will produce a random binary value. .Pp -Unlike -.Xr srand , -.Fn srandom -does not return the old seed; the reason for this is that the amount of -state information used is much more than a single word. (Two other -routines are provided to deal with restarting/changing random -number generators). Like +Like .Xr rand 3 , -however, .Fn random will by default produce a sequence of numbers that can be duplicated by calling @@ -161,11 +154,29 @@ is called with less than 8 bytes of state information, or if detects that the state information has been garbled, error messages are printed on the standard error output. .Sh SEE ALSO -.Xr rand 3 +.Xr rand 3 , +.Xr srand 3 .Sh HISTORY These functions appeared in .Bx 4.2 . .Sh BUGS +.Pp About 2/3 the speed of .Xr rand 3 . +.Pp +The historical implementation used to have a very weak seeding; the +random sequence did not vary much with the seed. For compatibility +reasons, this implementation has been made available until the +next FreeBSD release +via the +functions +.Fn orandom , +.Fn osrandom , +.Fn oinitstate +and +.Fn osetstate +from the compatibility library, +.Em libcompat . +The current implementation employs a better pseudo-random number +generator for the initial state calculation. |
