Getting documentation for shell builtins can be done using the command
help. For example:
$ help exec
exec: exec [-cl] [-a name] [command [arguments ...]] [redirection ...]
Replace the shell with the given command.
Execute COMMAND, replacing this shell with the specified program.
ARGUMENTS become the arguments to COMMAND. If COMMAND is not specified,
any redirections take effect in the current shell.
-a name pass NAME as the zeroth argument to COMMAND
-c execute COMMAND with an empty environment
-l place a dash in the zeroth argument to COMMAND
If the command cannot be executed, a non-interactive shell exits, unless
the shell option `execfail' is set.
Returns success unless COMMAND is not found or a redirection error occurs.
Otherwise, one could run
man bash and then search within this
(perhaps by typing
/\bexec\b, in this case, assuming a less-like