jot -- print sequential or random data
jot [-cnr] [-b word] [-w word] [-s string] [-p precision]
[reps [begin [end [s]]]]
The jot utility is used to print out increasing, decreasing, random, or
redundant data, usually numbers, one per line.
The following options are available:
-r Generate random data instead of the default sequential data.
Just print word repetitively.
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 are
inserted rather than appended.
-c This is an abbreviation for -w %c.
Print data separated by string. Normally, newlines separate
-n Do not print the final newline normally appended to the output.
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 precisions of begin and end. The -p option is
overridden by whatever appears in a printf(3) conversion following
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 -. 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
Defaults for the four arguments are, respectively, 100, 1, 100, and 1,
except that when random data are requested, the seed, s, is picked randomly.
The reps argument is expected to be an unsigned integer, and if
given as zero is taken to be infinite. The begin and end arguments 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 random(3). The name jot derives in
part from iota, a function in APL.
jot 21 -1 1.00
prints 21 evenly spaced numbers increasing from -1 to 1. The ASCII character
set is generated with
jot -c 128 0
and the strings xaa through xaz with
jot -w xa%c 26 a
while 20 random 8-letter strings are produced with
jot -r -c 160 a z | rs -g 0 8
Infinitely many yes's may be obtained through
jot -b yes 0
and thirty ed(1) substitution commands applying to lines 2, 7, 12, etc.
is the result of
jot -w %ds/old/new/ 30 2 - 5
The stuttering sequence 9, 9, 8, 8, 7, etc. can be produced by suitable
choice of step size, as in
jot - 9 0 -.5
and a file containing exactly 1024 bytes is created with
jot -b x 512 > block
Finally, to set tabs four spaces apart starting from column 10 and ending
in column 132, use
expand -`jot -s, - 10 132 4`
and to print all lines 80 characters or longer,
grep `jot -s "" -b . 80`
The jot utility exits 0 on success, and >0 if an error occurs. The following
diagnostic messages deserve special explanation:
illegal or unsupported format '%s' The requested conversion format specifier
for printf(3) was not of the form
where ``?'' must be one of
range error in conversion A value to be printed fell outside the range
of the data type associated with the requested output format.
too many conversions More than one conversion format specifier has been
supplied, but only one is allowed.
ed(1), expand(1), rs(1), yes(1), printf(3), random(3)
FreeBSD 5.2.1 June 6, 1993 FreeBSD 5.2.1 [ Back ]