Read from file<\/td> Write to file<\/td> Run the file<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nSpecify three permissions, one character for each of the three users.<\/p>\n\n\n\n
There are two ways to specify permissions: alphabetic and numerical.<\/p>\n\n\n\n
The table summarizes.<\/p>\n\n\n\npermission<\/th> alphabet<\/th> numerics<\/th><\/tr> Read<\/td> r<\/td> 4<\/td><\/tr> Write<\/td> w<\/td> 2<\/td><\/tr> Execute<\/td> x<\/td> 1<\/td><\/tr> None<\/td> -<\/td> 0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nAlphabetical designation<\/h5>\n\n\n\n The alphabetic symbol is a single letter of the word.<\/p>\n\n\n\n
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r<\/span><\/strong>ead<\/li>w<\/span><\/strong>rite<\/li>ex<\/span><\/strong>ecute<\/li><\/ul>\n<\/div>\n\n\n\nNumeric designation<\/h5>\n\n\n\n The number is expressed as a binary number with three digits.<\/p>\n\n\n\n
The order of the numbers looks like this<\/p>\n\n\n\nRead<\/td> Write<\/td> Execute<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nEach one uses the value of a flag of 1. It's easy to remember this table.<\/p>\n\n\n\n100<\/td> Read<\/td> 4<\/td><\/tr> 010<\/td> Write<\/td> 2<\/td><\/tr> 001<\/td> Execute<\/td> 1<\/td><\/tr><\/tbody><\/table>memorized table<\/figcaption><\/figure>\n\n\n\nSpecify multiple permissions numerically<\/h5>\n\n\n\n\n
It's readable and executable.<\/p>\n<\/div>\n\n\n\n
Thus, if you want to give multiple permissions, add them together.<\/p>\n\n\n\n
Then all permissions would look like this.<\/p>\n\n\n\n
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1 + 2 + 4 = 7<\/p>\n<\/div>\n\n\n\n
As we will see, the values we use are 0-7.<\/p>\n\n\n\n
A table of all permission patterns<\/h4>\n\n\n\n All permission patterns are summarized in the table.<\/p>\n\n\n\nValue<\/th> Binary digits<\/th> Symbol<\/th> Permissions to allow<\/th><\/tr><\/thead> 0<\/td> 000<\/td> ---<\/td> No authority at all.<\/td><\/tr> 1<\/td> 001<\/td> --x<\/td> Execute<\/td><\/tr> 2<\/td> 010<\/td> -w-<\/td> Write<\/td><\/tr> 3<\/td> 011<\/td> -wx<\/td> Write, Execute<\/td><\/tr> 4<\/td> 100<\/td> r--<\/td> Read<\/td><\/tr> 5<\/td> 101<\/td> r-x<\/td> Read, Execute<\/td><\/tr> 6<\/td> 110<\/td> rw-<\/td> Read, Write<\/td><\/tr> 7<\/td> 111<\/td> rwx<\/td> Read, Write, ExecuteAgain, these three character permissions are assigned to the owner, group and other users.<\/p>\n\n\n\n
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-rw-<\/span>rw-<\/span>r--<\/span><\/strong> 1 xxxxx yyyyy 1875611 Aug 16 23:57 zzzzzz <\/p>\n<\/div>\n\n\n\n\n
Red: owner<\/p>\n\n\n\n
Green: group<\/p>\n\n\n\n
Blue: Users other than the owner<\/p>\n<\/div>\n\n\n\n
Three color-coded permissions can be made.<\/p>\n\n\n\n
Permissions error<\/h4>\n\n\n\n If you try to operate on a file or directory without permission, an error occurs.<\/p>\n\n\n\n
Permission Error Messages<\/div>
Permission denied<\/code><\/pre>\n\n\n\nNumber of hard links<\/h3>\n\n\n\n\n
-rw-rw-r-- 1<\/span><\/strong> xxxxx yyyyy 1875611 Aug 16 23:57 zzzzzz <\/p>\n<\/div>\n\n\n\nNext to the permissions is the number of hard links, separated by a single space.<\/p>\n\n\n\n
There's not much point in knowing the details here, so this is about as much as you can remember.<\/p>\n\n\n\n
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file, the value is 1<\/li> directory, the approximate number of files and directories underneath<\/li><\/ul>\n<\/div>\n\n\n\n\n
In Linux, there are two hard links directly under the directory that count.<\/p>\n\n\n\n.<\/td> current directory<\/td><\/tr> ..<\/td> The parent (one level up) directory<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nIt's a number of hard links, so symbolic links do not count.<\/p>\n\n\n\n
In that sense, it won't be an exact number of files and directories.<\/p>\n<\/div>\n\n\n\n
Names of owners and groups<\/h3>\n\n\n\n\n
-rw-rw-r-- 1 xxxxx<\/span> yyyyy<\/span><\/strong> 1875611 Aug 16 23:57 zzzzzz <\/p>\n<\/div>\n\n\n\nNext to the number of hard links, space out one and show two names.<\/p>\n\n\n\n
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file owner's name<\/p>\n\n\n\n
The name of the group to which the file owner belongs<\/p>\n<\/div>\n\n\n\n
Leave one space between the owner's name and the group's name.<\/p>\n\n\n\n
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The owner of the file is the creator of the file<\/p>\n<\/div>\n\n\n\n
File Size<\/h3>\n\n\n\n\n
-rw-rw-r-- 1 xxxxx yyyyy 1875611<\/span><\/strong> Aug 16 23:57 zzzzzz <\/p>\n<\/div>\n\n\n\nNext to the owner's name and group name is the file size, with one space left blank.<\/p>\n\n\n\n
The unit is bytes and 0 for a directory.<\/p>\n\n\n\n
Update Date<\/h3>\n\n\n\n\n
-rw-rw-r-- 1 xxxxx yyyyy 1875611 Aug 16 23:57<\/span><\/strong> zzzzzz <\/p>\n<\/div>\n\n\n\nNext to the file size is the date and time of the file's last modification, with a single space after the file size.<\/p>\n\n\n\n
If it's a directory, it's the date and time the file was last modified when the directory configuration changed.<\/p>\n\n\n\n
If it is a new file, it is the date and time of its creation.<\/p>\n\n\n\n
The name of the file or directory<\/h3>\n\n\n\n