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NAME    [Toc]    [Back]

     jot - print sequential or random data

SYNOPSIS    [Toc]    [Back]

     jot [-cnr] [-b word] [-p precision] [-s string] [-w word]
         [reps [begin [end [s]]]]

DESCRIPTION    [Toc]    [Back]

     jot is used to print out increasing, decreasing, random,  or
redundant data,
 usually numbers, one per line.

     The options are as follows:

     -b word       Just print word repetitively.

     -c            This is an abbreviation for -w %c.

     -n             Do  not  print the final newline normally appended to the

     -p precision  Print only as many digits or characters of the
data as indicated
  by the integer precision.  In the absence of -p,
                   the precision is the greater  of  the  numbers
begin and end.
                   The  -p  option  is overridden by whatever appears in a
                   printf(3) conversion following -w.

     -r            Generate random data.  By default, jot  generates sequential

     -s  string      Print  data  separated by string.  Normally,
newlines separate

     -w word       Print word with the generated data appended to
it.  Octal,
                   hexadecimal,  exponential, ASCII, zero-padded,
and right-adjusted
 representations are possible  by  using
the appropriate
  printf(3) conversion specification inside
word, in
                   which case the data is  inserted  rather  than

     The  last four arguments indicate, respectively, the maximum
number of data,
 the lower bound, the upper bound,  and  the  step  size.
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 `-'.  Any three  of  these
arguments determines
  the  fourth.   If four are specified and the given
and computed
     values of reps conflict, the lower value is used.  If  fewer
than three
     are  specified,  defaults are assigned left to right, except
for s, which
     assumes its default unless both begin and end are given.

     Defaults for the four arguments are, respectively,  100,  1,
100, and 1.
     reps  is expected to be an unsigned integer, and if given as
zero is taken
     to be infinite.  begin and end may be given as real  numbers
or as characters
  representing  the  corresponding  value in ASCII.  The
last argument
     must be a real number.

     Random numbers are obtained through arc4random(3).  Historical versions
     of  jot used s to seed the random number generator.  This is
no longer
     supported.  The name jot derives in part from iota, a  function in APL.

   Rounding and truncation    [Toc]    [Back]
     The  jot utility uses double precision floating point arithmetic internally.
  Before printing a number, it is converted depending  on
the output
     format used.

     If  no  output format is specified or the output format is a
floating point
     format (`f', `e', `g', `E', or `G'), the  value  is  rounded
using the
     printf(3) function, taking into account the requested precision.

     If the output format is an integer format  (`c',  `d',  `o',
`x', `u', `D',
     `O', `X', `U', or `i'), the value is converted to an integer
value by

     As an illustration, consider the following command:

           $ jot 6 1 10 0.5

     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.

           $ jot -p 1 6 1 10 0.5

     By offsetting the values slightly, the values  generated  by
the following
     command are always rounded down:

           $ jot -p 0 6 .9999999999 10 0.5

     Another way of achieving the same result is to force truncation by specifying
 an integer format:

           $ jot -w %d 6 1 10 0.5

     For random sequences, the output format also influences  the
range and
     distribution of the generated numbers:

           $ jot -r 100000 1 3 | sort -n | uniq -c
           24950 1
           50038 2
           25012 3

     The values at the beginning and end of the interval are generated less
     frequently than the other values.  There are several ways to
solve this
     problem and generate evenly distributed integers:

           $ jot -r -p 0 100000 0.5 3.5 | sort -n | uniq -c
           33374 1
           33363 2
           33263 3

           $ jot -w %d -r 100000 1 4 | sort -n | uniq -c
           33306 1
           33473 2
           33221 3

     Note  that with random sequences, all numbers generated will
be smaller
     than the upper bound.  The largest value generated will be a
tiny bit
     smaller  than  the upper bound.  For floating point formats,
the value is
     rounded as described before being printed.  For integer formats, the
     highest  value  printed  will be one less than the requested
upper bound,
     because the generated value will be truncated.

EXAMPLES    [Toc]    [Back]

     Print 21 evenly spaced numbers increasing from -1 to 1:

           $ jot 21 -1 1.00

     Generate the ASCII character set:

           $ jot -c 128 0

     Generate the strings xaa through xaz:

           $ jot -w xa%c 26 a

     Generate 20 random 8-letter strings (note that the character
`{' comes
     after the character `z' in the ASCII character set):

           $ jot -r -c 160 a { | rs -g 0 8

     Infinitely many yes(1)'s may be obtained through:

           $ jot -b yes 0

     Thirty  ed(1)  substitution commands applying to lines 2, 7,
12, etc. is
     the result of:

           $ jot -w %ds/old/new/ 30 2 - 5

     Create a file containing exactly 1024 bytes:

           $ jot -b x 512 > block

     To set tabs four spaces apart starting from  column  10  and
ending in column
 132, use:

           $ expand -`jot -s, - 10 132 4`

     To print all lines 80 characters or longer:

           $ grep `jot -s "" -b. 80`

SEE ALSO    [Toc]    [Back]

     ed(1), expand(1), rs(1), yes(1), arc4random(3), printf(3)

OpenBSD      3.6                           June      6,      1993
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