hexdump - is a Linux utility to dump the file content into ascii, decimal, hexadecimal, octal formats. 

It accepts the input from a file or from standard input and creates a dump in ASCII, octal. hexadecimal or decimal formats.

FORMAT
      [-bcCdovx] [-e format_string] [-f format_file] [-n length] [-s skip] file ...

DESCRIPTION

SETFACL - set file access control lists or set special permissions to a file or directory.

FORMAT
       setfacl [-bkndRLPvh] [{-m|-x} acl_spec] [{-M|-X} acl_file] file ...

       setfacl --restore=file

DESCRIPTION
       This  utility  sets  Access  Control Lists (ACLs) of files and directories.  On the command line, a sequence of commands is followed by a sequence of files (which in turn can be followed by another sequence of commands, ...).

       The options -m, and -x expect an ACL on the command line. Multiple ACL entries are separated by comma characters (`,'). The options -M, and  -X ... Read more »

getent - get entries from Name Service Switch libraries or administrative databases like passwd, shadow, group etc.

FORMAT
getent [Options..] database [key ...]

DESCRIPTION
 

• The getent command displays entries from databases supported by the Name Service Switch libraries, which are configured in /etc/nsswitch.

TIME a simple command to give resource usage in Linux system

FORMAT
       time [options] command [arguments...]

DESCRIPTION
       The  time command runs the specified program/command with the given arguments.  When command finishes, time writes a message to standard error giving timing statistics about the program run.  

... Read more »

The command is used to configure kernel parameters at runtime

Most frequent usage:

1. Enable/disable IP forwarding
2. Change/Edit network configuration for ipv4/ipv6
3. Change/Edit kernel parameters like hostaname, domainname, max_lock_depth. ostype, pid_max etc
4. Change/edit file system

The command is used to get all the hops through which the packet is passing.

DESCRIPTION
       traceroute  tracks  the  route  packets take across a TCP/IP network on their way to a given host.

See the same command TRACERT in windows command line

How it works

SHOPT : Toggle the values of variables controlling optional shell behavior.

FORMAT:

 shopt [-pqsu] [-o] [optname ...]

   With no options, or with  the  -p option, a list of all settable options is displayed, with an indication of whether or not each is set.

... Read more »

Here in this article, we will learn how to change your command prompt strings in Linux environment or keep a prompt string of your own choice.

Before we change the command prompt strings, we need to learn the global variables $PS1, $PS2, $PS3, $PS4. Because these are the variable which defines the prompt strings. So lets have a look at short description on them.

• PS1: This is the global variable used to define the main prompt string in linux environmen

EXPORT is one of the most useful command in linux. It is used to set global variables in linux environment

FORMAT

export [-fn] [name[=word]] ...
export -p

              Names supplied to export are marked for automatic export to the environment of 

subsequen

       md5sum - compute and check MD5 message digest

FORMAT
       md5sum [OPTION] [FILE]...

DESCRIPTION
       Print  or  check  MD5 (128-bit) checksums.  With no FILE, or when FILE is -, read standard input.

       -b, --binary
              read in binary mode

       -c, --check
              read MD5 sums from the FILEs and check them

   &n ... Read more »