ownership

chown [OPTION]... [OWNER][:[GROUP]] FILE...

-c, --changes
    Report only when a change is made.

-f, --silent, --quiet
    Suppress most error messages.

-v, --verbose
    Output a diagnostic for every file processed.

--dereference
    Affect the referent of each symbolic link (this is the default), rather than the symbolic link itself.

--no-dereference
    Affect symbolic links instead of any referenced file.

-h, --no-dereference
    Affect each symbolic link instead of any referenced file.

--from=CURRENT_OWNER:CURRENT_GROUP
    Change the owner and/or group of each file only if its current owner and/or group match those specified here. Either may be omitted, in which case a wildcard value is assumed.

--preserve-root
    Fail to operate recursively on '/'.

--no-preserve-root
    Do not treat '/' specially (the default).

-R, --recursive
    Operate on files and directories recursively.

--reference=RFILE
    Use RFILE's owner and group rather than specifying OWNER:GROUP values.

OWNER
    Username or UID to set as the new owner.

GROUP
    Group name or GID to set as the new group. Omit GROUP to leave the group unchanged.

The chown command in Linux is used to change the ownership of files or directories. It allows you to modify which user and/or group is associated with a particular file, granting or restricting access as needed. This is a fundamental command for managing file permissions and security within a Linux environment. chown is typically executed with superuser privileges (root) or by the current owner of the file.
Incorrect usage of chown can lead to unintended security vulnerabilities, so it's crucial to understand its syntax and implications thoroughly. For example, changing ownership of system files without understanding consequences could lead to system instability or denial of service. Changing ownership might affect accessibility of configuration files, hence making programs non functional. The command is a cornerstone of Linux administration.

Requires root privileges to change ownership of files you don't own. Be careful when using the recursive option on system directories. On some systems changing the group of a file may require ownership of the file.

chown user file.txt changes the owner of file.txt to user.
chown user:group file.txt changes the owner to user and the group to group.
chown :group file.txt changes the group to group but leaves the owner unchanged.
chown -R user:group directory recursively changes the owner and group of all files and subdirectories within directory.

chown has been a fundamental part of Unix-like operating systems since their early days. Its purpose remains consistent: to provide a mechanism for managing file ownership and access control. Over time, the command's implementation has been refined, and additional features (like recursive operations) have been added. The command is standardized by POSIX.

chgrp(1), chmod(1), stat(1)