From the course: Linux CentOS 7: Files and Permissions
File and directory modes - Linux Tutorial
From the course: Linux CentOS 7: Files and Permissions
File and directory modes
- [Instructor] Standard Linux permissions support three different modes, read, write, and execute. These three modes provide different functionality for files and directories. For files, read access means the user can open and read the contents of a file. When a user has write access to a file, they can write or modify the contents. When a user has execute permissions on a file, it means that the file can be run as an application. Commands like LS and applications like Firefox would have their execute bit set. What happens when a command is executed, is it's loaded into memory and run until told to stop. These same three modes act differently on a directory. If a user has read access to a directory, it means they can list the contents of the directory, which includes the metadata about the files and directories in it. If a user doesn't have read access, and they type in LS inside the directory, you'll see a lot of question marks where the metadata should be. If a user has write access to a directory, it allows them to write to the directory. Writing to the directory means creating new files in it. Execute permissions on a directory are a bit at odd. You're not going to run a directory like you would a command. Execute permissions means that you can enter or traverse the directory.
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Contents
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Standard Linux permissions overview1m 47s
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File and directory modes1m 19s
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File ownership4m 34s
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Set permissions using numeric method3m 13s
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Set permissions using symbolic method5m 16s
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Default permissions using umask5m 51s
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Special file bits: SUID and SGID3m 49s
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Special directory bits: SGID and Sticky6m 26s
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