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NAMEjot —
print sequential or random data
SYNOPSIS
DESCRIPTIONThejot utility is used to print out increasing,
decreasing, random, or redundant data, usually numbers, one per line.
The following options are available:
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
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
arc4random(3)
when no seed is specified, and through
random(3)
when a seed is given. When The name Rounding and truncationThejot 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 (‘E’, ‘G’, ‘e’, ‘f’, 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 (‘D’, ‘O’, ‘U’, ‘X’, ‘c’, ‘d’, ‘i’, ‘o’, ‘u’, or ‘x’), the value is converted to an integer value by truncation. As an illustration, consider the following command: $ jot 6 1 10 0.5 1 2 2 2 3 4 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 1.0 1.5 2.0 2.5 3.0 3.5 By offsetting the values slightly, the values generated by the following command are always rounded down: $ jot -p 0 6 .9999999999 10 0.5 1 1 2 2 3 3 Another way of achieving the same result is to force truncation by specifying an integer format: $ jot -w %d 6 1 10 0.5 EXIT STATUSThejot utility exits 0 on success,
and >0 if an error occurs.
EXAMPLESThe commandjot - 1 10 prints the integers from 1 to 10, while the command 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 truncating the output precision and a suitable choice of step size, as in jot -w %d - 9.5 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` DIAGNOSTICSThe following diagnostic messages deserve special explanation:
SEE ALSOed(1), expand(1), rs(1), seq(1), yes(1), arc4random(3), printf(3), random(3)HISTORYThejot utility first appeared in
4.2BSD.
AUTHORSJohn A. Kunze
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