Basics in Unix System : Practice MCQ Questions & Answers with Explanations

With a 256-byte block and 2-byte addresses, a block holds 128 addresses. The max file size calculates to (12 + 128 + 128^2) × 256 bytes, which is slightly over 4 MB, meaning none of the listed options are correct.

Exporting the variable ensures it is passed to the subshell environments created by the sh -c command.

The script iterates through the words "my", "first", and "script", printing each consecutively to produce the full sentence.

Traditional UNIX kernels are monolithic, meaning the entire operating system runs in kernel space in supervisor mode, unlike microkernel architectures.

The command sequence sorts the contents of the 'in' file into a 'temp' file, outputs the first 30 lines of 'temp', and then deletes 'temp'.

The mv command essentially renames a file by modifying the directory entry to point to the existing i-node, without changing the i-node itself when on the same filesystem.

With 1 KB blocks and 4-byte addresses, a block holds 256 pointers. The triple indirect block allows 256^3 × 1 KB = 16 GB, dominating the maximum file size limit.

The signal handling mechanism involves kernel intervention to context-switch and execute the trap routine.

Bourne, C, and Korn are standard UNIX shells, whereas 'Net Shell' (netsh) is a command-line scripting utility in Windows.

The more command is a pager utility in UNIX that displays text one terminal screen (typically 24 lines) at a time.

The wc (word count) command, specifically with the -c or -m flag, is used to count the number of characters in a file.

sed, tail, and cut are standard UNIX text-processing utilities, whereas wart is not a standard UNIX command.

The chmod go-w command removes (-) the write (w) permissions for both the group (g) and others (o).

UNIX strictly follows the philosophy that "everything is a file", meaning hardware devices are accessed and treated just like regular files via device nodes in the /dev directory.

The mmap system call is used for memory management in UNIX to map files or devices into memory.

The /usr directory is a standard UNIX directory that contains user utilities and applications.

The nice command can adjust a process's scheduling priority up or down by modifying its "niceness" value.

While wc, whoami, and ls are standard shell commands, put is typically a command used specifically within FTP clients rather than a standalone UNIX shell command.

The fork() system call creates a new child process by duplicating the calling parent process.

The $PATH environment variable holds a colon-separated list of directories that the shell searches for executable files when a command is entered.