One of the reasons for ls having additional functionality, is that it is used in restricted shells - such as those used on rssh (SCP,SFTP, rsync and the like).

One of the reasons for ls having additional functionality, is that it is used in restricted shells - such as those used on rssh (SCP,SFTP, rsync and the like). There are no filtering utilities available in these shells: -rbash-3.2$ ls $PATH chmod cp groups ls mv rm scp