Ba hội Tam hoàng được đọc như sau: bộ ba đầu tiên bao gồm các nhân vật thứ hai, thứ ba và thứ tư trong danh sách định dạng tập tin dài. Bộ ba này sẽ thiết lập quyền truy cập cho người sử dụng, hoặc chủ sở hữu, của tập tin. (Chủ sở hữu sẽ được thảo luận trong phần "Ghi chú của chủ sở hữu", sau này trong chương này.) | 212 Part III Getting Up to Speed with Linux The three triads are read as follows The first triad consists of the second third and fourth characters in the long format file listing. This triad sets the permissions for the user or owner of the file. Owners are discussed in the Beware of owners section later in this chapter. The second triad consists of the fifth sixth and seventh characters in the long format file listing. This triad sets the permissions for the group that is assigned to the file. Groups are discussed in the Hanging out in groups section later in this chapter. The third triad consists of the eighth ninth and tenth characters in the long format file listing. This triad sets the permissions for other or everyone who isn t the file s owner or a member of the owning group. Although each triad is often different from the others the internal structure of each one is made up in the same way. Focus specifically on how to read one triad before looking at the set of them together. Each triad includes three characters 1 The first character is either an r or a dash. The r stands for read permission. If r is set the triad allows the entity it stands for user group or other to view the directory or file s contents. 1 The second character is either a w or a dash. The w stands for write permission. If w is set the triad allows the entity it stands for to add or edit items to or in this directory or file. The third character is either an x or a dash. The x stands for execute permission. If x is set the triad allows the entity it stands for to run programs contained in this directory or to run the particular program in this file. In all cases if the dash sits in place of r w or x the triad doesn t allow the entity the read write or execute permission. The following sections describe owners and groups in more detail. Beware of owners You may have noticed by now that I talk a great deal about owners users and groups in Linux. Every file and directory has both of these .
