Linux commands easily overlooked

Unlike other operating systems, GNU/Linux comes with a enriched application tool-chain and thus, some of them are easily overlooked by the average Linux user.

While learning about "how to create a Linux system from scratch" I've found that, just if we are limiting to the base components we'll find few dozens of useful tools that either we haven't known that they exist or worst, we forgot them on the way.

I've created a list of those commands, grouped by their container, as a reference for the future use/practice:

• Util-linux

  • cfdisk (like fdsik but using nice ncurses menus)

  • column - Formats a given file into multiple columns

  • findmnt - Is a command line interface to the libmount library for work with mountinfo, fstab and mtab files

  • lsblk - Lists information about all or selected block devices in a tree-like format

  • lscpu - Prints CPU architecture information

  • pg - like more/less but displays a text file one screen full at a time

  • script - Makes a typescript of a terminal session

  • scriptreplay - Plays back typescripts using timing information

  • sfdisk - like parted, a disk partition table manipulator

  • whereis - Reports the location of the binary, source, and man page for the given command

• Psmisc

  • pstree - Displays running processes as a tree

• Procps

  • pmap - Reports the memory map of the given process

  • pwdx - Reports the current working directory of a process

  • w - Shows which users are currently logged on, where, and since when

• E2fsprogs

  • badblocks - Searches a device (usually a disk partition) for bad blocks

  • e2freefrag - Reports free space fragmentation information

  • e4defrag - Online defragmenter for ext4 filesystems

  • filefrag - Reports on how badly fragmented a particular file might be

• Shadow

  • lastlog - Reports the most recent login of all users or of a given user

  • pwck - Verifies the integrity of the password files /etc/passwd and /etc/shadow

  • pwconv - Creates or updates the shadow password file from the normal password file

  • pwunconv - Updates /etc/passwd from /etc/shadow and then deletes the latter

• Coreutils

  • nl - Numbers the lines from the given files

  • nohup - Runs a command immune to hangups, with its output redirected to a log file

  • od - Dumps files in octal and other formats

• Iana-etc

  • /etc/protocols - Describes the various DARPA Internet protocols that are available from the TCP/IP subsystem

  • /etc/services - Provides a mapping between friendly textual names for internet services, and their underlying assigned port numbers and protocol types

• Inetutils

  • rcp - Performs remote file copy

  • rexec - executes commands on a remote host

  • rlogin - Performs remote login

  • rsh - Runs a remote shell

  • talk - Is used to chat with another user

• Gawk

  • pwcat - Dumps the password database /etc/passwd

• IPRoute

  • lnstat - provides Linux network statistics. It is a generalized and more feature-complete replacement for the old rtstat program

  • nstat - Shows network statistics

  • routel - A component of ip route. This is for listing the routing tables

  • rtstat - Route status utility

  • ss - Similar to the netstat command; shows active connections

• Man-DB

  • apropos - Searches the whatis database and displays the short descriptions of system commands that contain a given string

  • whatis - Searches the whatis database and displays the short descriptions of system commands that contain the given keyword as a separate word

• Sysvinit

  • last - Shows which users last logged in (and out), searching back through the /var/log/wtmp file; it also shows system boots, shutdowns, and run-level changes

  • lastb - Shows the failed login attempts, as logged in /var/log/btmp