Category Archives: Linux

Watch disk usage updating every 3 seconds:watch -d -n 3 ‘df -h’

Sed strings make VIM very powerful. You can use them to do many things. The changes will not be written to the file until you save the file, so you are safe to experiment a bit. To delete lines 4-12: … Continue reading →

Tar and encrypt: tar cz <dir>/ | openssl enc -aes-256-cbc -pbkdf2 -iter 10000 -e > out.tar.gz.enc Decrypt:openssl enc -aes-256-cbc -d -in out.tar.gz.enc | tar xz

Since RedHat/Ubuntu/Debian’s /proc/cpuinfo has a separate entry for each CPU core, you can use this command to count them:cat /proc/cpuinfo | grep processor | wc -l Or do it with the following Python script:—-!/usr/bin/env python3 import osimport psutil l1, l2, l3 = … Continue reading →

To convert a UTF-8 encoded file to UTF-16, you can use iconv on the command line: iconv -f utf-8 -t utf-16 oldfile > newfile

To connect to MySQL through a tunnel Open a tunnel on your local machine listening on localhost:3307 and forwarding everything to the mysqlserver server on port 3306, and doing it all via the ssh service on the gateway machine. ssh … Continue reading →

If you are using an updated openssh package and suddenly can’t connect to sites that you could before the update, you can add an option to your .ssh/config file (create it if you don’t have one). If you see this … Continue reading →

telnet can be used to connect you to servername on a specified port. You can gather information from the data returned from that connection: telnet servername.com port Then type: HEAD / HTTP/1.0 bash-3.2# telnet 310.210.7.222 80 Trying 310.210.7.222… Connected to … Continue reading →

ping – probes hosts on the attached network link by sending icmp packets sent over IP tcping – reports the reachability and round-trip time of an IP address hosted on the local network arping – probes hosts on the attached … Continue reading →