ls long listing format各个字段的含义
-rw-r--r-- 1 root root 2 Jul 27 13:30 bar
-rw-rw-r-- 1 root root 7056 Jul 27 13:27 foo
For each directory that is listed, preface the files with a line ‘total BLOCKS’, where BLOCKS is the total disk allocation for all files in that directory. The block size currently defaults to 1024 bytes, but this can be overridden (*note Block size::). The BLOCKS computed counts each hard link separately; this is arguably a deficiency.
From the output above we can deduct a following information:
- -rw-rw-r- permissions
- 1 : number of linked hard-links
- root: owner of the file
- root: to which group this file belongs to
- 7056: file size
- Jul 27 13:27 modification date and time
- foo: file/directory name
To answer your question we will look more closely at the permissions part of ls long listing format output:
The file type is one of the following characters:
- - regular file
- b block special file
- c character special file
- C high performance (“contiguous data”) file
- d directory
- D door (Solaris 2.5 and up)
- l symbolic link
- M off-line (“migrated”) file (Cray DMF)
- n network special file (HP-UX)
- p FIFO (named pipe)
- P port (Solaris 10 and up)
- s socket
- ? some other file type
The file mode bits listed are similar to symbolic mode specifications (*note Symbolic Modes::).
But `ls’ combines multiple bits into the third character of each set of permissions as follows:
- s If the set-user-ID or set-group-ID bit and the corresponding executable bit are both set.
- S If the set-user-ID or set-group-ID bit is set but the corresponding executable bit is not set.
- t If the restricted deletion flag or sticky bit, and the other-executable bit, are both set.The restricted deletion flag is another name for the sticky bit. *Note Mode Structure::.
- T If the restricted deletion flag or sticky bit is set but the other-executable bit is not set.
- x If the executable bit is set and none of the above apply.
- - Otherwise.