nostr:npub1n783957maa2g7rpdyd5knx0whfggllws33clq9qg4dme3wauxrvq6q87ev nostr:npub1wg02ev7lfmnrwsjqu2tcm2qm4gw65aw0dyywfwvgafqnqyf02wmqhht0yf Just shifts ascii range around a bit, basically

tr ' -/:-@[-`{-}' '`-{/" -'

using s/// to initialize the buffer, y/// to do the replacement and then s/// again to do the system call. If sed did support ranges and unequal sets in y///; it could've been just sed.