'-e sh shell.c' as a single argument is the same as '-e' and ' sh shell.c' as separate arguments (see <https://pubs.opengroup.org/onlinepubs/9799919799/function

'-e sh shell.c' as a single argument is the same as '-e' and ' sh shell.c' as separate arguments (see <https://pubs.opengroup.org/onlinepubs/9799919799/functions/getopt.html https://pubs.opengroup.org/onlinepubs/9799919799/functions/g...>). rsync executes ' sh shell.c' as a shell script and shells usually trim leading and trailing spaces when executing commands.