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Restore jot's ability to use a seed for producing a deterministic

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sequence of random numbers.
This functionality was lost in revision 1.9 when the random number
generator was switched to arc4random.

PR:		docs/54879
MFC after:	2 weeks
This commit is contained in:
Diomidis Spinellis 2006-11-06 10:30:29 +00:00
parent 55f965ae6a
commit a26a66124e
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=164026
2 changed files with 18 additions and 7 deletions
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6
usr.bin/jot/jot.1
View File

@ -139,7 +139,11 @@ representing the corresponding value in
The last argument must be a real number.
.Pp
Random numbers are obtained through
.Xr random 3 .
.Xr arc4random 3
when no seed is specified,
and through
.Xr random 3
when a seed is given.
The name
.Nm
derives in part from

19
usr.bin/jot/jot.c
View File

@ -57,6 +57,7 @@ __FBSDID("$FreeBSD$");
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
@ -102,6 +103,7 @@ main(int argc, char **argv)
unsigned int mask = 0;
int n = 0;
int ch;
bool have_seed = false;
while ((ch = getopt(argc, argv, "rb:w:cs:np:")) != -1)
switch (ch) {
@ -142,6 +144,8 @@ main(int argc, char **argv)
if (!sscanf(argv[3], "%lf", &s))
errx(1, "bad s value: %s", argv[3]);
mask |= HAVE_STEP;
if (randomize)
have_seed = true;
}
/* FALLTHROUGH */
case 3:
@ -206,7 +210,7 @@ main(int argc, char **argv)
mask |= HAVE_BEGIN;
break;
case HAVE_REPS | HAVE_ENDER:
s = (randomize ? time(NULL) : STEP_DEF);
s = STEP_DEF;
mask = HAVE_REPS | HAVE_ENDER | HAVE_STEP;
break;
case HAVE_REPS | HAVE_ENDER | HAVE_STEP:
@ -218,7 +222,7 @@ main(int argc, char **argv)
mask = 0;
break;
case HAVE_REPS | HAVE_BEGIN:
s = (randomize ? -1.0 : STEP_DEF);
s = STEP_DEF;
mask = HAVE_REPS | HAVE_BEGIN | HAVE_STEP;
break;
case HAVE_REPS | HAVE_BEGIN | HAVE_STEP:
@ -229,9 +233,7 @@ main(int argc, char **argv)
mask = 0;
break;
case HAVE_REPS | HAVE_BEGIN | HAVE_ENDER:
if (randomize)
s = -1.0;
else if (reps == 0)
if (reps == 0)
errx(1, "infinite sequences cannot be bounded");
else if (reps == 1)
s = 0.0;
@ -257,8 +259,13 @@ main(int argc, char **argv)
infinity = 1;
if (randomize) {
x = (ender - begin) * (ender > begin ? 1 : -1);
if (have_seed)
srandom((unsigned long)s);
for (i = 1; i <= reps || infinity; i++) {
y = arc4random() / ((double)UINT32_MAX + 1);
if (have_seed)
y = random() / ((double)LONG_MAX + 1);
else
y = arc4random() / ((double)UINT32_MAX + 1);
if (putdata(y * x + begin, reps - i))
errx(1, "range error in conversion");
}