Bash Cache

cache

#!/bin/sh
# forked from http://stackoverflow.com/a/11901300/129492

if [ $# == 0 ] || [ $1 == '-h' ] || [ $1 == '--help' ]; then
    echo 'cache - cache the output of a command'
    echo
    echo 'Usage: cache [options] <command>'
    echo
    echo 'Options:'
    echo ' -r, --reset [command]'
    echo '     Reset the cache. If a command is provided,'
    echo '     the only the cache for that command is reset;'
    echo '     otherwise, the entire cache is reset.'
    echo
    echo '-h, --help'
    echo '     Display this message'
    exit
fi

if [ $1 == '-r' ] || [ $1 == '--reset' ]; then
    reset=1
    shift
fi

cacheroot=/tmp/bashcache

# clear entire cache
if [ -n "$reset" ] && [ $# == 0 ]; then
  rm -rf $cacheroot
  exit
fi

mkdir -p $cacheroot
cachefile=$cacheroot/out
for i in "$@"; do
    cachefile=${cachefile}_$(printf %s "$i" | sed 's/./\\&/g')
done

# clear specific cache
if [ -n "$reset" ]; then
    rm -f $cachefile
fi

test -f "$cachefile" || "$@" > "$cachefile"
cat "$cachefile"

Just came across this gist, and I'm curious if you've looked at bash-cache (I talk about it another answer on the linked question). It supports a number of features beyond this caching pattern, including support for environment variables, user-private caches preserving stderr as well as stdout, and asynchronous cache-warming. Feedback is welcome!