RANDOM(1)

NAME

random - generate a random integer between two values

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SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
AUTHOR
COPYRIGHT
BUG REPORTS

SYNOPSIS

random [-u] [-g [-c center]] [-s seed] [-v] low high

DESCRIPTION

random prints a single random integer between low and high (inclusive bounds) to standard output. Both low and high are required integer arguments.

By default, or when -u is given, the value is drawn from a uniform distribution across the range. When -g is given, the value is instead drawn from a gaussian distribution centered on the midpoint of the range, or on an explicit -c center, and clamped to the low-to_high_ range. The uniform and gaussian modes are mutually exclusive.

The random sequence is seeded from the process ID unless a fixed -s seed is supplied, making a run reproducible.

OPTIONS

-u: Draw from a uniform distribution across the range. This is the default when neither -u nor -g is given.
-g: Draw from a gaussian distribution centered on the range midpoint (or on -c center) and clamped to low and high.
-c center: Set the gaussian center to the given (possibly fractional) value instead of the range midpoint. Only meaningful with -g.
-s seed: Use the given integer to seed the random number generator. The same seed yields the same value, allowing reproducible runs. Defaults to the process ID.
-v: Print verbose diagnostics (seed, mode, and parameters) to standard error before the result.
-h, -?: Print a usage message and exit.

EXAMPLES

Example 1. Pick a uniform roll and capture it in a shell variable

roll=$(random 1 6)
echo "you rolled a $roll"

Emulates a six-sided die by selecting a uniform integer between 1 and 6.

Example 2. Reproducible gaussian value clustered near a chosen center

random -g -c 50 -s 42 0 100

Draws a value between 0 and 100 from a gaussian distribution centered on 50. The fixed seed of 42 makes the result repeatable, which is useful for deterministic tests or scripted scenes.