Say grep is aliases to "
grep --color -Hn". This can be annoying in case the output must be send through a pipe to another command because it always prints the source and the line number.
One way of avoiding the alias is to pass the full path, e.g. "/bin/grep". Another way is to quote the command e.g. "'grep'" and the quicker and nicest way is to put the two quotes before the command e.g. "''grep".