stefanlasiewski

# List all network interfaces on my Mac

```
$ networksetup -listallnetworkservices
An asterisk (*) denotes that a network service is disabled.
Display Ethernet
Thunderbolt Ethernet
Wi-Fi
Display FireWire
Bluetooth PAN

stefanlasiewski

$ docker run -it ubuntu
root@14d8108342b9:/# cat /etc/issue
Ubuntu 16.04.1 LTS \n \l
root@14d8108342b9:/# apt-get -qq update && apt-get -qq upgrade && apt-get -qq install build-essential
debconf: delaying package configuration, since apt-utils is not installed
(Reading database ... 7259 files and directories currently installed.)
Preparing to unpack .../libc6_2.23-0ubuntu5_amd64.deb ...
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 76.)
debconf: falling back to frontend: Readline

stefanlasiewski

#!/usr/bin/env bash

# A handy way to redirect script output to syslog
# Way more granular then adding a bunch of `/usr/bin/logger` stanzas

# Thanks to http://urbanautomaton.com/blog/2014/09/09/redirecting-bash-script-output-to-syslog/ &
# Eric at https://twitter.com/lindvall/status/509054237267853312

echo "writing to stdout, before the I/O redirection"

stefanlasiewski

# Tested from a Mac command-line
$ dig +noall +answer SFDPH.ORG
$ dig +noall +answer www.SFDPH.ORG
www.sfdph.org.		1638	IN	CNAME	evqf8.x.incapdns.net.
evqf8.x.incapdns.net.	29	IN	A	199.83.131.153
$ 

stefanlasiewski

#!/usr/bin/env bash

#set -xv

# Update MacPorts base to latest released version using 'selfupdate'
# Then upgrade all outdated ports (upgrade outdated), and uninstall old version of each port (-u),
# following these guides:
# http://guide.macports.org/#using.common-tasks.updating
# http://guide.macports.org/#using.port.upgrade

stefanlasiewski

[root@devdb ~]# yum remove mysql-commercial\*
Loaded plugins: fastestmirror, priorities, ps, security, versionlock
Setting up Remove Process
Resolving Dependencies
--> Running transaction check
---> Package mysql-commercial-client.x86_64 0:5.7.22-1.1.el6 will be erased
---> Package mysql-commercial-common.x86_64 0:5.7.22-1.1.el6 will be erased
---> Package mysql-commercial-libs.x86_64 0:5.7.22-1.1.el6 will be erased
--> Processing Dependency: mysql-libs for package: 2:postfix-2.6.6-6.el6_5.x86_64
---> Package mysql-commercial-libs-compat.x86_64 0:5.7.22-1.1.el6 will be erased

stefanlasiewski

[root@devdb ~]# yum list --quiet mysql-community-server mysql-community-client mysql-community-libs mysql-community-common mysql-community-libs-compat
Available Packages
mysql-community-client.x86_64                              5.7.22-1.el6                        mysql57-community 
mysql-community-common.x86_64                              5.7.22-1.el6                        mysql57-community 
mysql-community-libs.x86_64                                5.7.22-1.el6                        mysql57-community 
mysql-community-libs-compat.x86_64                         5.7.22-1.el6                        mysql57-community 
mysql-community-server.x86_64                              5.7.22-1.el6                        mysql57-community
[root@devdb ~]# yum --quiet downgrade mysql-community-libs-5.7.22-1.el6.x86_64 mysql-community-common-5.7.22-1.
el6.x86_64 mysql-community-client-5.7.22-1.el6.x86_64 mysql-community-libs-compat-5.7.22-1.el6.x86_64 mys
ql-community-server-5.7.22-1.el6.x86_64

stefanlasiewski

# Coreutils 8.24+ ships with dd with the status=progress option

root@host:~# dd if=/dev/sdb conv=sync,noerror status=progress | lz4 > disk.img.lz4
1430323712 bytes (1.4 GB, 1.3 GiB) copied, 41 s, 34.9 MB/s

# pv (Pipeview) can also show a nice progress bar

root@host:~# dd if=/dev/sdb conv=sync,noerror | pv -tpreb | lz4 > ~stefanl/touch.img.lz4
472MiB 0:00:14 [36.0MiB/s] [                           <=>                                                  ]

stefanlasiewski

By default, `git branch` by default uses a pager, which requires that you quit out of the pager, which erases the results fmor your screen

stefanl@stefanl:zfs git branch --all

* master
  remotes/origin/HEAD -> origin/master
  remotes/origin/master
  remotes/origin/top
  remotes/origin/zfs-0.6.3-stable
(END)^C

stefanlasiewski

By default, `journalctl` will print the logs through a pager which can hide results from you. This can be annoying when trying to capture a screenshot:

root@docker01:~# journalctl -xe -u docker
May 21 23:25:40 docker01 dockerd[123]: time="2020-05-21T23:25:40.376573968Z" level=info msg="ign
May 22 00:45:37 docker01 dockerd[123]: time="2020-05-22T00:45:37.971043364Z" level=info msg="ign
lines 1006-1046/1046 (END)

Instead, pipe `journalctl` through `less`, `cat` or `tail` to quickly get familiar features such as wrapped lines:

root@docker01:~# journalctl -xe -u docker