feat: add CLI random number generator supporting 6 distributions

2026-06-12 14:14:31 +08:00
commit 2a17ca30cb
11 changed files with 634 additions and 0 deletions
@@ -0,0 +1,35 @@
+export const HELP = `rand — Generate random numbers
+
+Usage:
+  rand [options] [args]
+
+Options:
+  -c, --count <n>     Number of random numbers to output (default: 1)
+  -f[N]               Decimal places: -f = -f2 (default: 2)
+  --float [N]         Long form of -f
+  -d, --dist <name>   Distribution (default: uniform)
+  -h, --help          Show this help
+
+Distributions and their positional args:
+  uniform             rand [min] [max]               (default: 0 100)
+  normal              rand -d normal [mean] [stddev]  (default: 0 1)
+  binomial            rand -d binomial [n] [p]        (default: 10 0.5)
+  poisson             rand -d poisson [lambda]        (default: 1)
+  exponential         rand -d exponential [lambda]    (default: 1)
+  hypergeometric      rand -d hypergeometric [N] [K] [n]
+                                                  (default: 100 50 10)
+
+Examples:
+  rand                               # uniform 0–100
+  rand -d normal                     # normal μ=0, σ=1
+  rand -d normal 100 15 -f1          # normal μ=100, σ=15, 1 decimal
+  rand -d binomial 20 0.3 -c 5     # 5 binomial(n=20, p=0.3)
+  rand -d poisson 3                  # poisson λ=3
+  rand -d exponential 0.5            # exponential λ=0.5
+  echo "5 2" | rand -d normal       # stdin overrides positional args
+  rand | xargs echo                 # pipe output`;
+
+export function showHelp(): never {
+  console.log(HELP);
+  process.exit(0);
+}