Consulte a seção "comandos internos do shell" de man bash
; ele possui uma entrada para shopt
que descreve todas as opções de shell disponíveis. Aqui está um trecho:
shopt [-pqsu] [-o] [optname ...]
[...]
autocd If set, a command name that is the name of a directory
is executed as if it were the argument to the cd com-
mand. This option is only used by interactive shells.
cdable_vars
If set, an argument to the cd builtin command that is
not a directory is assumed to be the name of a variable
whose value is the directory to change to.
cdspell If set, minor errors in the spelling of a directory com-
ponent in a cd command will be corrected. The errors
checked for are transposed characters, a missing charac-
ter, and one character too many. If a correction is
found, the corrected file name is printed, and the com-
mand proceeds. This option is only used by interactive
shells.
[...]