chmod:tldr:bc0c6

The command "chmod o= ${filename}" is used to change the permissions (access rights) for the "others" category of users in a Linux or Unix system.

Here's a breakdown of the command:

• "chmod" stands for "change mode," and it is a command used to modify the permissions of files or directories.
• "o=" indicates that we are modifying the permissions for the "others" category of users, i.e., those who are not the owner or belonging to the group associated with the file.
• "${filename}" is a placeholder for the actual name of the file or directory for which we want to change the permissions.

In summary, this command sets the permissions for the "others" category to "=" (none), meaning that they will have no permissions to read, write, or execute the specified file or directory.