====== Permissions cheatsheet ======

[[man>chmod]], [[man>chown]]

FIXME prepsat z http://blog.harvie.cz/useful-gnulinux-commands/

===== Meaning of RWX Combinations =====

^ Octal digit ^ Text equivalent ^ Binary value ^ Meaning ^
| 0 | ''%%---%%'' | 000 | All types of access are denied |
| 1 | ''%%--x%%'' | 001 | Execute access is allowed only |
| 2 | ''%%-w-%%'' | 010 | Write access is allowed only |
| 3 | ''%%-wx%%'' | 011 | Write and execute access are allowed |
| 4 | ''%%r--%%'' | 100 | Read access is allowed only |
| 5 | ''%%r-x%%'' | 101 | Read and execute access are allowed |
| 6 | ''%%rw-%%'' | 110 | Read and write access are allowed |
| 7 | ''%%rwx%%'' | 111 | Everything is allowed |


===== Meaning of RWX bits for files and folders =====

^ Access type ^ File ^ Folder ^
| Read | If the file contents can be read | If the directory listing can be obtained |
| Write | If user or process can write to the file (change its contents) | If user or process can change directory contents somehow: create new or delete existing files in the directory or rename files. |
| Execute | If the file can be executed | If user or process can access the directory, that is, go to it (make it to be the current working directory) |

===== Digital representation of setuid, setgid and sticky bits =====

^ Octal digit ^ Binary value ^ Meaning ^
| 0 | 000 | setuid, setgid, sticky bits are cleared |
| 1 | 001 | sticky bit is set |
| 2 | 010 | setgid bit is set |
| 3 | 011 | setgid and sticky bits are set |
| 4 | 100 | setuid bit is set |
| 5 | 101 | setuid and sticky bits are set |
| 6 | 110 | setuid and setgid bits are set |
| 7 | 111 | setuid, setgid, sticky bits are set |


===== Meanings of SUID, SGID and Sticky bits =====

^ SUID | If set, then replaces "x" in the owner permissions to "s",\\ if owner has execute permissions, or to "S" otherwise.\\ Examples:\\ **''%%-rws------%%''** both owner execute and SUID are set\\ **''%%-r-S------%%''** SUID is set, but owner execute is not set |
^ SGID | If set, then replaces "x" in the group permissions to "s",\\ if group has execute permissions, or to "S" otherwise.\\ Examples:\\ **''%%-rwxrws---%%''** both group execute and SGID are set\\ **''%%-rwxr-S---%%''** SGID is set, but group execute is not set |
^ Sticky | If set, then replaces "x" in the others permissions to "t",\\ if others have execute permissions, or to "T" otherwise.\\ Examples:\\ **''%%-rwxrwxrwt%%''** both others execute and sticky bit are set\\ **''%%-rwxrwxr-T%%''** sticky bit is set, but others execute is not set |