This page lists some simple commands, code snippets and questions that attendees should understand before coming to class.
- How to list running processes?
- How to kill/terminate a process?
- Find all TCP and UDP listeners on Linux system.
- What is a difference between process and thread?
- How to redirect output of one program into input of another in Unix-like system?
- What is the purpose of
/var,/home,/bin,/mntand/srvdirectories in Linux filesystem?- What is the fundamental difference between
/srv,/mntand/opt?
- What is the fundamental difference between
- How to set an IP address to network interface from command line without editing any files or restarting any services?
- What is a regular expression?
- What is syslog?
- Where are log files usually located on a Linux system?
- Linux file system hierarchy
- Vim or Nano. First one is preferred and used by teachers.
- "Predictable" network interface naming
- tcpdump
FILE=/etc/apt/apt.conf.d/99force-ipv4
[[ -f $FILE ]] || echo 'Acquire::ForceIPv4 "true";' | sudo tee $FILE
for src in et/open ptresearch/attackdetection oisf/trafficid; do suricata-update list-enabled-sources | grep $src || suricata-update enable-source $src >> /vagrant/provision.log 2>&1 ; done
#!/bin/bash
if [[ ! -f /var/run/generator-2 ]]; then
while : ; do curl -s https://www.facebook.com/ > /dev/null 2>&1 ; sleep 10 ; done & sleep 1; echo $! > /var/run/generator-1
while : ; do curl -s http://testmyids.com > /dev/null 2>&1 ; sleep 10 ; done & sleep 1; echo $! > /var/run/generator-2
while : ; do curl -s http://tumblr.com > /dev/null 2>&1 ; sleep 10 ; done & sleep 1; echo $! > /var/run/generator-3
fi
What is the difference between these two echo statements?
export myname="CDMCS"
echo "$myname"
echo '$myname'
import json
def task(data={"foo":"bar"}):
return json.dumps(data).encode(encoding="utf-8") "\n".encode(encoding="utf8")
echo foo | python -c "import sys; print(sys.stdin.read())"