pa8mm.net - linux
http://pa8mm.net/
2026-07-12T13:27:24+00:00pa8mm.net
http://pa8mm.net/
http://pa8mm.net/lib/exe/fetch.php?media=wiki:dokuwiki.svgtext/html2026-05-15T13:30:56+00:00Anonymous (anonymous@undisclosed.example.com)bash
http://pa8mm.net/doku.php?id=linux:bash&rev=1778851856&do=diff
BASH
WILDCARD METACHARACTERS & EXPANSION
The shell expands special characters (globs/wildcards) before passing arguments to commands. This is called pathname expansion (or globbing).
Core wildcards:
* * - zero or more characters. Example: ls *.jpgtext/html2026-03-27T20:32:12+00:00Anonymous (anonymous@undisclosed.example.com)bird
http://pa8mm.net/doku.php?id=linux:bird&rev=1774643532&do=diff
BIRD
CONFIGURATION
/etc/bird.conf
include "/etc/bird.d/*.conf";
protocol direct direct1 {
interface "lo";
debug all;
export none;
import where net ~ MY_NETWORKS; # from the protocol to the RIB
}
protocol bgp NORTH {
disabled no;
description "North peer";
neighbor fd00::1 as 65000;
source address fd00::2;
import all;
export none; # From the routing table to protocol
direct;
next hop self;
…text/html2026-02-13T18:52:55+00:00Anonymous (anonymous@undisclosed.example.com)git
http://pa8mm.net/doku.php?id=linux:git&rev=1771008775&do=diff
GIT
CHECK OUT REMOTE BRANCH
git switch --track origin/branch-name // 1. Creates a new local branch called branch-name
// 2. Set its upstream to origin/branch-name (the remote branch)
// 3. Move your working directory to that branchtext/html2026-03-27T20:34:27+00:00Anonymous (anonymous@undisclosed.example.com)networking
http://pa8mm.net/doku.php?id=linux:networking&rev=1774643667&do=diff
IP FORWARDING
sysctl net.ipv4.ip_forward # check if enabled
sysctl -w net.ipv4.ip_forward=1 # turning on
echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf
SCP
$ scp username@remotehost:file_name.txt /local/directory # from remote to local
$ scp file_name.txt username@remotehost:/remote/directory # from local to remote
$ scp -r dir_name username@remotehost:/remote/directory # copy the local directory "dir_name" to
# r…text/html2026-03-27T20:35:06+00:00Anonymous (anonymous@undisclosed.example.com)net_tshoot
http://pa8mm.net/doku.php?id=linux:net_tshoot&rev=1774643706&do=diff
NETWORKING TROUBLESHOOTING
Excellent article: Troubleshooting
One more article: Mellanox
GENERIC
Show NIC type:
$ lspci | grep net
03:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5719 Gigabit Ethernet PCIe (rev 01)
Show generic information about NIC (supported modes, current speed/duplextext/html2026-02-05T21:00:24+00:00Anonymous (anonymous@undisclosed.example.com)public_key
http://pa8mm.net/doku.php?id=linux:public_key&rev=1770325224&do=diff
PUBLIC KEY AUTHENTICATION FOR SSH
OVERVIEW
SSH keeys come in pairs:
* .ssh/id_rsa - private key
* .ssh/id_rsa.pub - public key
Public key should be copied to servers into ~/.ssh/authorized_keys (it let's the server authenticate the user).
During the client authentication, the client will use its private key, and it will be verified by the public key stored intext/html2026-03-20T12:35:54+00:00Anonymous (anonymous@undisclosed.example.com)ripgrep
http://pa8mm.net/doku.php?id=linux:ripgrep&rev=1774010154&do=diff
RipGrep
Glob
--glob parameter controls which files and directories are included or excluded from the search.
rg "pattern" --glob '!**/*.yaml' # ! - exclude
# **/ - matches any directory depth
# *.yaml - any files ending with .yamltext/html2026-05-18T15:07:52+00:00Anonymous (anonymous@undisclosed.example.com)ssh
http://pa8mm.net/doku.php?id=linux:ssh&rev=1779116872&do=diff
SSH
PUBLIC KEY AUTHENTICATION
SSH AGENT
ssh-agent is a background process that holds your decrypted private keys in memory so you don't have to type the passphrase every time you SSH somewhere. Private SSH keys should be encrypted on disk with a passphrase. Without an agent, every ssh, git pull, scp etc. would prompt you to type that passphrase to decrypt the key.text/html2026-05-20T08:01:44+00:00Anonymous (anonymous@undisclosed.example.com)text
http://pa8mm.net/doku.php?id=linux:text&rev=1779264104&do=diff
WORKING WITH TEXT IN LINUX
TR
tr (translate) is a stream filter that operates on single characters, not patterns or words. It reads stdin and writes stdout, transforming one character at a time.
SQUEEZE
Squeeze (-s) collapse repeats:
tr -s ' ' # multiple spaces → single space
tr -s '\n' # collapse blank lines
tr -s ' ' ',' # squeeze spaces AND translate to comma (combined)text/html2026-03-06T13:18:13+00:00Anonymous (anonymous@undisclosed.example.com)tls
http://pa8mm.net/doku.php?id=linux:tls&rev=1772803093&do=diff
TLS
ВВЕДЕНИЕ
В TLS используются два типа ключей - public и private.
private ключ всегда остается у владельца и не разглашается.
KEYS
* Certificate (Public Key): *.crt, *.pemtext/html2026-03-27T20:36:15+00:00Anonymous (anonymous@undisclosed.example.com)users
http://pa8mm.net/doku.php?id=linux:users&rev=1774643775&do=diff
MANAGING USERS
CHANGING IDENTITIES
There are two option to take on the identity of another user:
* su - start the shell as another user or issue a single command as that user
* sudo - allows a user to execute commands as a different user (usually the root). Config file