Linux command-line tools I usually install

Some additional command-line tools that I use to install and use on my text client Systems. Initially here were not listed commands that are shipped with every Linux, but the additional tools I install in every Workstation or Server.

Apache benchmarks

To stress a Web Server

bzip2

Cool compressor better than gzip and that also accepts streams.

ctop

Command line / text based Linux Containers monitoring tool

dmidecode

Is the dmi Table decoder.

For example: dmidecode -t memory

edac-util

Error reporting utility

edac-util --verbose
mc0: 0 Uncorrected Errors with no DIMM info
mc0: 0 Corrected Errors with no DIMM info
mc0: csrow0: 0 Uncorrected Errors
mc0: csrow0: CPU_SrcID#0_MC#0_Chan#0_DIMM#0: 0 Corrected Errors
mc0: csrow0: CPU_SrcID#0_MC#0_Chan#1_DIMM#0: 0 Corrected Errors
mc0: csrow0: CPU_SrcID#0_MC#0_Chan#2_DIMM#0: 0 Corrected Errors
mc1: 0 Uncorrected Errors with no DIMM info
mc1: 0 Corrected Errors with no DIMM info
mc1: csrow0: 0 Uncorrected Errors
mc1: csrow0: CPU_SrcID#0_MC#1_Chan#0_DIMM#0: 0 Corrected Errors
mc1: csrow0: CPU_SrcID#0_MC#1_Chan#1_DIMM#0: 0 Corrected Errors
mc1: csrow0: CPU_SrcID#0_MC#1_Chan#2_DIMM#0: 0 Corrected Errors
mc2: 0 Uncorrected Errors with no DIMM info
mc2: 0 Corrected Errors with no DIMM info
mc2: csrow0: 0 Uncorrected Errors
mc2: csrow0: CPU_SrcID#1_MC#0_Chan#0_DIMM#0: 0 Corrected Errors
mc2: csrow0: CPU_SrcID#1_MC#0_Chan#1_DIMM#0: 0 Corrected Errors
mc2: csrow0: CPU_SrcID#1_MC#0_Chan#2_DIMM#0: 0 Corrected Errors
mc3: 0 Uncorrected Errors with no DIMM info
mc3: 0 Corrected Errors with no DIMM info
mc3: csrow0: 0 Uncorrected Errors
mc3: csrow0: CPU_SrcID#1_MC#1_Chan#0_DIMM#0: 0 Corrected Errors
mc3: csrow0: CPU_SrcID#1_MC#1_Chan#1_DIMM#0: 0 Corrected Errors
mc3: csrow0: CPU_SrcID#1_MC#1_Chan#2_DIMM#0: 0 Corrected Errors

ethtool

ethtool

fatrace
Reports file access events from all running processes in real time.

flock
With flock several processes can have a shared lock at the same time, or be waiting to acquire a write lock. With lslocks from util-linux package you can get a list of these processes.

fstrim

discard unused blocks on a mounted filesystem (local or remote). Is useful for freeing blocks no longer used in ZFS zvols. That can also be achieved by mount -o discard

fuser
Show which processes use the named files, sockets, or filesystems.

git

hdparm
Get/set SATA/IDE device parameters

htop

An improved top

id (configure to query OpenLDAP)

ifmetrics

To set the metrics of all IPV4 routes attached to a given network interface

iftop

To watch metrics for a network interface (or wireless)

iftop-wlan0

iostat

CPU and IO devices stats. I modified some collectors for telegraf and influxdb consumed by grafana for fetching the Write KB/s, Read KB/s, Bandwidth of the Magnetic Spinning drives and SSD during declustered rebuild.

iotop

iperf

Perform network throughput tests

ipmitool

iptables

iscsiadm

java (jre Oracle and OpenJDK)

journalctl

ldap-utils

ldapsearch and the other tools to work with LDAP.

less
According to manpages, the opposite of more. :)
What it does is display a file, and you can scroll up/down, you can search for patterns…
Examples:
cat /etc/passwd | less
less /etc/passwd
# -n doesn’t count the lines, to save time
# For a specific Offset
less -n +500000000P /var/log/apache2/giant.log
# For 50% point
less -n +50p /var/log/apache2/giant.log

lrzip /lrztar

Compressor that compresses very efficiently big files, specially GB of of source code.

lrzsz (Zmodem)

An utility to send files to the Server through a terminal.

Very useful when you don’t want to scp or rsftp, for example because that requires MFA  (Multi Factor Authentication) to be performed again and you already have a session open.

Moba xTerm for Windows is one of the Terminal clients that accepts Upload/Download of Z-modem

Moba xTerm for Windows is one of the Terminal clients that accepts Upload/Download of Z-modem

apt install lrzsz

lynx

Text browser. really handy.

ltrace
To trace library calls.

mc

Midnight Commander

mc

 

md5sum

mtr

Network tool mix between ping and traceroute.

mytop

To see in real time queries and slow queries to mysql

ncdu

Show the space used by any directory and subdirectory

ncdu

ncdu-2

nginx (fpm-php) and apache

The webservers

nfs client

nmon

Offers monitoring of different aspects: Network, Disk, Processes…

open-vpn

openssh-server

parted

Partition manipulation

perf

Performance profiler.

Ie:
perf top
perf stat ls

PHP + curl + mysql (hhvm)

pixz

A parallel, multiprocessor, variant of gzip/bzip2 that can leverage several processors to speed up the compression over files.

If the input looks like a tar archive, it also creates an index of all the files in the archive. This allows the extraction of only a small segment of the tarball, without needing to decompress the entire archive.

postcat

postcat -q ID shows the details of a message in the queue

python-pip and pypy

pv
Pipe Viewer – is a terminal-based tool for monitoring the progress of data through a pipeline. It can be inserted into any normal pipeline between two processes to give a visual indication of how quickly data is passing through, how long it has taken, how near to completion it is, and an estimate of how long it will be until completion.

dd if=/dev/urandom | pv | dd of=/dev/null

Output:

1,74MB 0:00:09 [ 198kB/s] [      <=>                               ]

Probably you’ll prefer to use dd with status=progress option, it’s just a sample.

qshape

It shows the composition of the mail queue.

screen

sdparm
Access SCSI modes pages; read VPD pages; send simple SCSI commands

sfdisk

Utility to work with partitions that can export and import configs through STDIN and STDOUT to automate partitions operations.

slabtop
Displays Kernel slab cache information in real time.

smartctl

Utility for dealing with the S.M.A.R.T. features of the disks, knowing errors…

split
Split a file into several, based by text lines, or binary: number of bytes per file.

sshfs

Mount a mountpoint on a remote Server by using SSH.

sshpass
SSH without typing the password. -f for reading it from a file.
sshpass -p “mypassword” ssh -o StrictHostKeyChecking=no root@10.251.35.251

In this sample passing the command ls, so this will be executed, and logout.
sshpass -p “mypassword” ssh -o StrictHostKeyChecking=no root@10.251.35.251 ls

sshuttle

A poor’s man VPN through SSH that is available for Linux and Mac OS X.

E.g.: sudo sshuttle -r carles@8.8.1.234:8275 172.30.0.0/16

Sshuttle forwards TCP and DNS but does not forward UDP or ICMP. So ping or ipmi protocol won’t work. But it does work for http, https, ssh…

Nice article on tunneling only certain things here.

strace

To trace the system calls and signals.
To redirect the output to another process use:
strace zpool status 2>&1 | less

strings

Shows only strings from a file (normally a Binary)

From package binutils.

subversion svn

systemd-cgtop and systemd-analyze

tcpdump

To see the traffic to your NIC

tee

Reads from sdtin and sends to a file and outputs to stdout as well.
For example:

find . -mtime -1 -print | grep -v "/logs/" 2>&1 | tee /var/log/results.log

timeout
Kills the process after the indicated timeout.

timeout 1000 dd if=/dev/urandom of=/dev/zvol/carles-N51-C5-D8-P2-S1/gb1000

tracepath

traceroute

tree

Tree simply shows the directory hierarchy in a graphical (text mode) way. Useful to see where files and subfolders are.

xxd
Make a hexdump or do the reverse

sudo xxd /dev/nvme0n1p1 | less

zcat
Just like cat, but for compressed filed.

zcat logs.tar.gz | grep "Error"
zcat logs.tar.gz | less

zless

zram-config

Sergey Davidoff stumbled upon a project called compcache that creates a RAM based block device which acts as a swap disk, but is compressed and stored in memory instead of swap disk (which is slow), allowing very fast I/O and increasing the amount of memory available before the system starts swapping to disk. compcache was later re-written under the name zRam and is now integrated into the Linux kernel.

http://www.webupd8.org/2011/10/increased-performance-in-linux-with.html

watch

Whatch allow you to execuate a command and what it (refresh it) at a given intervals, for example every two seconds.
For example, if normally I would do:

 while [ true ]; do zpool status | head -n10 ; sleep 10; done 
 while [ true ]; do df -h; sleep 60; done 
while [ true ]; do ls -al /tmp | head -n5 ; sleep 2; done 

Then I can do:

watch -n10 zpool status

Or:

watch -n60 df -h

Or

watch "ls -al /tmp | head -n5"

For my Dockers, and cloudinit with Ubuntu, my defaults are:

apt update; apt install htop mc ncdu strace git binutils
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2 thoughts on “Linux command-line tools I usually install

  1. Michael

    Very useful, thanks Carles. For me, several of these are new, including fatrace (I never saw ncdu before either, but I do, e.g., du -sk *|sort -n)

    Reply
    1. Carles Mateo Post author

      Thanks Michael :)
      Actually the way you use du -sk * | sort -n is clever.
      Another idea, if you run as non privileged user on / and you want the errors reporting no permissions not to annoy you, you can do as well:
      du -sk * 2>/dev/null | sort -n

      Reply

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