在bash中选择随机目录的脚本

不需要任何外部命令( ls , find , sort , head )为了这个:

#!/usr/bin/env bash
set -o nullglob       # make globs expand to nothing, not themselves, when no matches found
dirs=( "$1"*/ )       # list directories starting with $1 into an array

# Validate that our glob actually had at least one match
(( ${#dirs[@]} )) || { printf 'No directories start with %q at all\n' "$1" >&2; exit 1; }

idx=$(( RANDOM % ${#dirs[@]} ))  # pick a random index into our array
echo "${dirs[$idx]}"             # and look up what's at that index