Jawaharlal Nehru Technological University Hyderabad B.Tech IV LINUX PROGRAMMING Previous Question Paper (September - 2020 - R16)

Backup utilities are used to archive and compress files for data protection, while process utilities manage and monitor running tasks.

Backup Utilities:

1. tar (Tape Archive): Used to create or extract archives. Syntax:
   tar [options] [archive-file] [file/directory]
   Options: -c (create), -x (extract), -v (verbose), -f (file). Example:
   tar -cvf backup.tar /home/user/docs
2. gzip: Used for compression. Syntax:
   gzip [options] [filename]
   Option: -d (decompress). Example:
   gzip file.txt

Process Utilities:

1. ps (Process Status): Displays information about active processes. Syntax:
   ps [options]
   Options: -e (all processes), -f (full format). Example:
   ps -ef
2. top: Provides a dynamic real-time view of running processes. Syntax:
   top
3. kill: Sends a signal to terminate a process. Syntax:
   kill [signal] [PID]
   Example:
   kill -9 1234

I/O redirection allows users to change the standard input, output, or error streams of a command.

• Output Redirection (>): Redirects standard output to a file, overwriting existing content. Example:
  ls > list.txt
• Append Redirection (>>): Appends standard output to the end of a file without overwriting. Example:
  echo "data" >> log.txt
• Input Redirection (<): Redirects standard input from a file instead of the keyboard. Example:
  sort < input.txt
• Error Redirection (2>): Redirects only the error messages (stderr) to a file. Example:
  command 2> error.log
• Combined Redirection (&>): Redirects both standard output and standard error to the same file. Example:
  command &> output.log
• Pipe (|): Takes the output of one command and uses it as the input for another. Example:
  ls | grep 'txt'