linux/unix cheatsheet

linux_cheatsheet.txt

disk usage (https://superuser.com/a/1573074/619805):

sudo du -hsx /* | sort -rh | head -n 40
du -schx .[!.]* * | sort -h 

get proc envs:
sudo cat /proc/803/environ | xargs -0 env -i

get public IP from CLI:
dig +short myip.opendns.com @resolver1.opendns.com

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ssh tunnels (with -L but with key auth):

`~/.ssh/config`:
Host computeinstance
HostName 20.22.222.222
User azureuser
Port 50001
IdentityFile ~/.ssh/id_rsa
ForwardAgent yes
LocalForward 6006 127.0.0.1:6006

check active tunnels:
`lsof -i -n | egrep '\<ssh\>'`


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bash check port:
$ timeout 2 bash -c "</dev/tcp/HOST.com/80"; echo $?
0 -> means good
127 -> bad, port closed/firewall/vNet
124 -> port reachable but closed/disabled


macOS time shift:
sudo sntp -sS pool.ntp.org


Get amout of lines in the codebase:
find . -name '*.py' -o -name '*.tf' -o -name '*.yaml' -o -name '*.yml' | xargs wc -l


if you need an indicator of consumed space in your compute instance while dockering:
watch -n5.5 --no-title "df -h | head -2 | grep -o '.\{5\}$'"