702-100 Exam Dumps : Linux Professional Institute BSD Specialist

The setenv command is used to set an environment variable in the csh or tcsh shell. The syntax is setenv VAR VALUE, where VAR is the name of the variable and VALUE is the value to assign to it. The TZ variable is used to specify the timezone for the shell and its subprocesses. To set the timezone to GMT (Greenwich Mean Time), the command is setenv TZ GMT. This will affect the output of commands like date and ls that display time information. The other options are either invalid syntax or belong to other shells, such as bash or sh. References:

• setenv - Linux setenv command help and examples1
• TZ - FreeBSD Environment Variables2

The file command is used to determine the type of data contained in a computer file. It performs a series of tests on the file and prints a description of the file type based on the first successful test. The file command can take one or more file names as its arguments. For example, file mybackup will display the file type of mybackup. The other options are not valid commands for finding the file type. References:

• file command in Linux with examples
• file (command) - Wikipedia
• Linux File Command

The umask command in BSD is used to set default permissions for files or directories the user creates1. The umask value is permissions to deny, taken off whatever permissions would be given by default2. The default permission values for files are 666 (rw-rw-rw-), meaning read and write for user, group, and others3. The umask value of 022 means that the permissions to deny are 022 (—w–w-), meaning write for group and others. To calculate the default permissions for newly created files, we need to subtractthe umask value from the default permission value, using bitwise AND operation4. For example:

666 - 022 = 644 rw-rw-rw- - —w–w- = rw-r–r–

Therefore, the default permissions for newly created files with a umask of 022 are 644 (rw-r–r–), meaning read and write for user, and read for group and others.

References: 1: Umask command in Linux with examples - GeeksforGeeks 2: Different permission between directory and file with ‘umask’ - Unix & Linux Stack Exchange 3: Default File Permissions (umask) - docs.oracle.com 4: What is Umask and How to Use It {Update Default Linux File Permissions} - phoenixNAP KB