Syslog is a protocol for conveying event notification messages. Syslog concepts and calls for logging messages are explained.
Linux commands, last and lastb, for printing user login history are explained with examples.
tmpfs is a temporary filesystem that resides in the main memory of a Linux system.
The cut command cuts sections of each line of input files and writes it on its standard output. It is mostly used for taking out a few columns from the input files.
The tr command is a filter which reads the standard input, translates or deletes characters and writes the resulting text on its standard output.
The comm command compares two sorted files and gives output in three columns, containing the lines present only in the first file, the lines present only in the second file and the lines common to both files respectively.
The uniq command is a filter for finding unique lines in input. It reads input, suppresses duplicates and prints unique lines in its output.
The sort command is for sorting lines in text files. There are options to define keys, reverse sort order, numeric sort and to merge files.
awk is a filter which takes the input and gives output after matching desired patterns and doing processing linked to matched patterns.
sed is a stream editor that applies the commands one by one on each line of input and writes the resulting lines on the standard output.
grep is a program for searching a given string pattern in files. It searches files for the pattern and prints the lines that match the pattern.
A bash script is a list of commands written to automate some system operations work in Linux. The commands for making a bash script are explained.
A command line interface (CLI) shell provides a powerful, precise and flexible way of running commands. bash is the default CLI shell under Linux.
tc is a user space program for managing qdiscs for network interfaces. tc is used for configuring traffic control in the kernel.
The ss command gives the socket statistics. It gives information about the network connections. ss is a replacement for the netstat command.