a811237df2
The way jot(1) defaults missing arguments doesn't match the behaviour described in the manpage, which states that with fewer than 3 arguments missing values are supplied from left to right. In fact, with one or two arguments, the last (s which is step size or seed) defaults to 1 (or -1 if begin and end specify a descending range), and then omitted arguments are set to default starting with the leftmost until three arguments are available. This is why `jot 2 1000` prints 1000 and 1001 instead of 1000 and 100. PR: 135475 Submitted by: Jonathan McKeown <j.mckeown@ru.ac.za> Approved by: doc (bcr) Differential Revision: https://reviews.freebsd.org/D21736 Event: EuroBSDcon 2019
331 lines
7.9 KiB
Groff
331 lines
7.9 KiB
Groff
.\" Copyright (c) 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)jot.1 8.1 (Berkeley) 6/6/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd September 21, 2019
|
|
.Dt JOT 1
|
|
.Os
|
|
.Sh NAME
|
|
.Nm jot
|
|
.Nd print sequential or random data
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl cnr
|
|
.Op Fl b Ar word
|
|
.Op Fl w Ar word
|
|
.Op Fl s Ar string
|
|
.Op Fl p Ar precision
|
|
.Op Ar reps Op Ar begin Op Ar end Op Ar s
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility is used to print out increasing, decreasing, random,
|
|
or redundant data, usually numbers, one per line.
|
|
.Pp
|
|
The following options are available:
|
|
.Bl -tag -width indent
|
|
.It Fl r
|
|
Generate random data instead of the default sequential data.
|
|
.It Fl b Ar word
|
|
Just print
|
|
.Ar word
|
|
repetitively.
|
|
.It Fl w Ar word
|
|
Print
|
|
.Ar word
|
|
with the generated data appended to it.
|
|
Octal, hexadecimal, exponential,
|
|
.Tn ASCII ,
|
|
zero padded,
|
|
and right-adjusted representations
|
|
are possible by using the appropriate
|
|
.Xr printf 3
|
|
conversion specification inside
|
|
.Ar word ,
|
|
in which case the data are inserted rather than appended.
|
|
.It Fl c
|
|
This is an abbreviation for
|
|
.Fl w Ar %c .
|
|
.It Fl s Ar string
|
|
Print data separated by
|
|
.Ar string .
|
|
Normally, newlines separate data.
|
|
.It Fl n
|
|
Do not print the final newline normally appended to the output.
|
|
.It Fl p Ar precision
|
|
Print only as many digits or characters of the data
|
|
as indicated by the integer
|
|
.Ar precision .
|
|
In the absence of
|
|
.Fl p ,
|
|
the precision is the greater of the precisions of
|
|
.Ar begin
|
|
and
|
|
.Ar end .
|
|
The
|
|
.Fl p
|
|
option is overridden by whatever appears in a
|
|
.Xr printf 3
|
|
conversion following
|
|
.Fl w .
|
|
.El
|
|
.Pp
|
|
The last four arguments indicate, respectively,
|
|
the number of data, the lower bound, the upper bound,
|
|
and the step size or, for random data, the seed.
|
|
While at least one of them must appear,
|
|
any of the other three may be omitted, and
|
|
will be considered as such if given as
|
|
.Fl ""
|
|
or as an empty string.
|
|
Any three of these arguments determines the fourth.
|
|
If four are specified and the given and computed values of
|
|
.Ar reps
|
|
conflict, the lower value is used.
|
|
If one or two are specified, defaults are assigned
|
|
starting with
|
|
.Ar s ,
|
|
which assumes a default of 1 (or -1 if
|
|
.Ar begin
|
|
and
|
|
.Ar end
|
|
specify a descending range).
|
|
Then the default values are assigned to the leftmost omitted arguments until
|
|
three arguments are set.
|
|
.Pp
|
|
Defaults for the four arguments are, respectively,
|
|
100, 1, 100, and 1, except that when random data are requested,
|
|
the seed,
|
|
.Ar s ,
|
|
is picked randomly.
|
|
The
|
|
.Ar reps
|
|
argument is expected to be an unsigned integer,
|
|
and if given as zero is taken to be infinite.
|
|
The
|
|
.Ar begin
|
|
and
|
|
.Ar end
|
|
arguments may be given as real numbers or as characters
|
|
representing the corresponding value in
|
|
.Tn ASCII .
|
|
The last argument must be a real number.
|
|
.Pp
|
|
Random numbers are obtained through
|
|
.Xr arc4random 3
|
|
when no seed is specified,
|
|
and through
|
|
.Xr random 3
|
|
when a seed is given.
|
|
When
|
|
.Nm
|
|
is asked to generate random integers or characters with begin
|
|
and end values in the range of the random number generator function
|
|
and no format is specified with one of the
|
|
.Fl w ,
|
|
.Fl b ,
|
|
or
|
|
.Fl p
|
|
options,
|
|
.Nm
|
|
will arrange for all the values in the range to appear in the output
|
|
with an equal probability.
|
|
In all other cases be careful to ensure that the output format's
|
|
rounding or truncation will not skew the distribution of output
|
|
values in an unintended way.
|
|
.Pp
|
|
The name
|
|
.Nm
|
|
derives in part from
|
|
.Nm iota ,
|
|
a function in APL.
|
|
.Ss Rounding and truncation
|
|
The
|
|
.Nm
|
|
utility uses double precision floating point arithmetic internally.
|
|
Before printing a number, it is converted depending on the output
|
|
format used.
|
|
.Pp
|
|
If no output format is specified or the output format is a
|
|
floating point format
|
|
.Po
|
|
.Sq E ,
|
|
.Sq G ,
|
|
.Sq e ,
|
|
.Sq f ,
|
|
or
|
|
.Sq g
|
|
.Pc ,
|
|
the value is rounded using the
|
|
.Xr printf 3
|
|
function, taking into account the requested precision.
|
|
.Pp
|
|
If the output format is an integer format
|
|
.Po
|
|
.Sq D ,
|
|
.Sq O ,
|
|
.Sq U ,
|
|
.Sq X ,
|
|
.Sq c ,
|
|
.Sq d ,
|
|
.Sq i ,
|
|
.Sq o ,
|
|
.Sq u ,
|
|
or
|
|
.Sq x
|
|
.Pc ,
|
|
the value is converted to an integer value by truncation.
|
|
.Pp
|
|
As an illustration, consider the following command:
|
|
.Bd -literal -offset indent
|
|
$ jot 6 1 10 0.5
|
|
1
|
|
2
|
|
2
|
|
2
|
|
3
|
|
4
|
|
.Ed
|
|
.Pp
|
|
By requesting an explicit precision of 1, the values generated before rounding
|
|
can be seen.
|
|
The .5 values are rounded down if the integer part is even,
|
|
up otherwise.
|
|
.Bd -literal -offset indent
|
|
$ jot -p 1 6 1 10 0.5
|
|
1.0
|
|
1.5
|
|
2.0
|
|
2.5
|
|
3.0
|
|
3.5
|
|
.Ed
|
|
.Pp
|
|
By offsetting the values slightly, the values generated by the following
|
|
command are always rounded down:
|
|
.Bd -literal -offset indent
|
|
$ jot -p 0 6 .9999999999 10 0.5
|
|
1
|
|
1
|
|
2
|
|
2
|
|
3
|
|
3
|
|
.Ed
|
|
.Pp
|
|
Another way of achieving the same result is to force truncation by
|
|
specifying an integer format:
|
|
.Bd -literal -offset indent
|
|
$ jot -w %d 6 1 10 0.5
|
|
.Ed
|
|
.Sh EXIT STATUS
|
|
.Ex -std
|
|
.Sh EXAMPLES
|
|
The command
|
|
.Dl jot - 1 10
|
|
.Pp
|
|
prints the integers from 1 to 10,
|
|
while the command
|
|
.Dl jot 21 -1 1.00
|
|
.Pp
|
|
prints 21 evenly spaced numbers increasing from -1 to 1.
|
|
The
|
|
.Tn ASCII
|
|
character set is generated with
|
|
.Dl jot -c 128 0
|
|
.Pp
|
|
and the strings xaa through xaz with
|
|
.Dl jot -w xa%c 26 a
|
|
.Pp
|
|
while 20 random 8-letter strings are produced with
|
|
.Dl "jot -r -c 160 a z | rs -g 0 8"
|
|
.Pp
|
|
Infinitely many
|
|
.Em yes Ns 's
|
|
may be obtained through
|
|
.Dl jot -b yes 0
|
|
.Pp
|
|
and thirty
|
|
.Xr ed 1
|
|
substitution commands applying to lines 2, 7, 12, etc.\& is
|
|
the result of
|
|
.Dl jot -w %ds/old/new/ 30 2 - 5
|
|
.Pp
|
|
The stuttering sequence 9, 9, 8, 8, 7, etc.\& can be
|
|
produced by truncating the output precision and a suitable choice of step size,
|
|
as in
|
|
.Dl jot -w %d - 9.5 0 -.5
|
|
.Pp
|
|
and a file containing exactly 1024 bytes is created with
|
|
.Dl jot -b x 512 > block
|
|
.Pp
|
|
Finally, to set tabs four spaces apart starting
|
|
from column 10 and ending in column 132, use
|
|
.Dl expand -`jot -s, - 10 132 4`
|
|
.Pp
|
|
and to print all lines 80 characters or longer,
|
|
.Dl grep `jot -s \&"\&" -b \&. 80`
|
|
.Sh DIAGNOSTICS
|
|
The following diagnostic messages deserve special explanation:
|
|
.Bl -diag
|
|
.It "illegal or unsupported format '%s'"
|
|
The requested conversion format specifier for
|
|
.Xr printf 3
|
|
was not of the form
|
|
.Dl %[#][ ][{+,-}][0-9]*[.[0-9]*]?
|
|
where
|
|
.Dq ?\&
|
|
must be one of
|
|
.Dl [l]{d,i,o,u,x}
|
|
or
|
|
.Dl {c,e,f,g,D,E,G,O,U,X}
|
|
.It "range error in conversion"
|
|
A value to be printed fell outside the range of the data type
|
|
associated with the requested output format.
|
|
.It "too many conversions"
|
|
More than one conversion format specifier has been supplied,
|
|
but only one is allowed.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr ed 1 ,
|
|
.Xr expand 1 ,
|
|
.Xr rs 1 ,
|
|
.Xr seq 1 ,
|
|
.Xr yes 1 ,
|
|
.Xr arc4random 3 ,
|
|
.Xr printf 3 ,
|
|
.Xr random 3
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
utility first appeared in
|
|
.Bx 4.2 .
|
|
.Sh AUTHORS
|
|
.An John A. Kunze
|