How to Check MD5 Sums of Installed Packages in Debian/Ubuntu Linux

Have you ever wondered why a given binary or package installed on your system does not work according to you expectations, meaning it does not function correctly as it is supposed to do, perhaps it can not event start at all.

While downloading packages, you may face challenges of unsteady network connections or unexpected power blackouts, this can result into installation of corrupted package.

Considering this as an important factor in maintaining uncorrupted packages on your system, it is therefore a vital step to verify the files on the file system against the information stored in the package by using following article.

Learn How to Generate and Verify Files with MD5 Checksum in Linux

A checksum is a digit which serves as a sum of correct digits in data, which can be used later to detect errors in the data during storage or transmission. MD5 (Message Digest 5) sums can be used as a checksum to verify files or strings in a Linux file system.

MD5 Sums are 128-bit character strings (numerals and letters) resulting from running the MD5 algorithm against a specific file. The MD5 algorithm is a popular hash function that generates 128-bit message digest referred to as a hash value, and when you generate one for a particular file, it is precisely unchanged on any machine no matter the number of times it is generated.

fswatch – Monitors Files and Directory Changes or Modifications in Linux

fswatch is a cross-platform, file change monitor that gets notification alerts when the contents of the specified files or directories are altered or modified.

It executes four types of monitors on different operating systems such as:

1. A monitor build on the File System Events API of Apple OS X.
2. A monitor based on kqueue, a notification interface present in FreeBSD 4.1 also supported on many *BSD systems, OS X inclusive.
3. A monitor based on File Events Notification API of the Solaris kernel plus its spin-offs.
4. A monitor based on inotify, a kernel subsystem that shows file system modifications to apps.
5. A monitor based on ReadDirectoryChangesW, a Windows API that records alters to a directory.
6. A monitor that regularly check that status of file system, keeps file modification times in memory, and manually determine file system changes (which works anywhere, where stat can be used).

Progress – A Tiny Tool to Monitor Progress for (cp, mv, dd, tar, etc.) Commands in Linux

Progress, formerly known as Coreutils Viewer, is a light C command that searches for coreutils basic commands such as cp, mv, tar, dd, gzip/gunzip, cat, grep etc currently being executed on the system and shows the percentage of data copied, it only runs on Linux and Mac OS X operating systems.

Additionally, it also displays important aspects such as estimated time and throughput, and offers users a “top-like” mode.

11 Advanced Linux ‘Grep’ Commands on Character Classes and Bracket Expressions

Have you ever been into a situation where you need to search for a string, word or pattern inside a file? if yes, then the grep utility comes handy in such situation.

grep is a command line utility for searching plain-text data for lines which matching a regular expression. If you will divide the word grep like g/re/p then the meaning of grep is (globally search a regular expression and print) which search pattern from the file and print the line on the screen i.e. standard output.

15 Examples of How to Use New Advanced Package Tool (APT) in Ubuntu/Debian

One important thing to master under Linux System/Server Administration is package management using different package management tools.

Different Linux distributions install applications in a pre-compiled package that contain binary files, configuration files and also information about the application’s dependencies.

Read Also: Learn 25 ‘apt-get’ and ‘apt-cache’ Command Examples in Debian based Systems

Package management tools help System/Server Administrators in many ways such as:

ifconfig vs ip: What’s Difference and Comparing Network Configuration

Linux based distributions have featured set of commands which provide way to configure networking in easy and powerful way through command-line. These set of commands are available from net-tools package which has been there for a long time on almost all distributions, and includes commands like: ifconfig, route, nameif, iwconfig, iptunnel, netstat, arp.

Ifconfig Vs IP Command