Articles

Wed, 10 Jun 2026 10:59:53 +0800

Linux 系统误将 chmod 权限改成了 000，如何恢复?

#include <sys/stat.h>

int main() {
 chmod("/usr/bin/chmod", 0755);
 return 0;
}

ubuntu@ubuntu:~$ which chmod
/usr/bin/chmod
ubuntu@ubuntu:~$ ls -lh /usr/bin/chmod
lrwxrwxrwx 1 root root 8 Sep 27 2025 /usr/bin/chmod -> gnuchmod
ubuntu@ubuntu:~$ ls -lh /usr/bin/gnuchmod
-rwxr-xr-x 1 root root 67K Jan 23 21:34 /usr/bin/gnuchmod
ubuntu@ubuntu:~$ sudo chmod 000 /usr/bin/chmod
ubuntu@ubuntu:~$ ls -lh /usr/bin/chmod
lrwxrwxrwx 1 root root 8 Sep 27 2025 /usr/bin/chmod -> gnuchmod
ubuntu@ubuntu:~$ ls -lh /usr/bin/gnuchmod
---------- 1 root root 67K Jan 23 21:34 /usr/bin/gnuchmod
ubuntu@ubuntu:~$ cat main.c
#include <sys/stat.h>

int main() {
 chmod("/usr/bin/chmod", 0755);
 return 0;
}

ubuntu@ubuntu:~$ gcc ./main.c
ubuntu@ubuntu:~$ sudo ./a.out
ubuntu@ubuntu:~$ ls -lh /usr/bin/chmod
lrwxrwxrwx 1 root root 8 Sep 27 2025 /usr/bin/chmod -> gnuchmod
ubuntu@ubuntu:~$ ls -lh /usr/bin/gnuchmod
-rwxr-xr-x 1 root root 67K Jan 23 21:34 /usr/bin/gnuchmod

Laptops all have built-in security tokens these days

macOS

https://github.com/yubico/libfido2

Why is this running?

Tue, 30 Dec 2025 11:33:23 +0800

Why is this running?

Expose your local web server to the internet with a public URL.

Sat, 27 Dec 2025 15:24:41 +0800

Expose your local web server to the internet with a public URL.

A fast and powerful log viewer and processor that converts JSON logs or logfmt logs into a clear human-readable format.

Sun, 14 Dec 2025 21:06:20 +0800

A fast and powerful log viewer and processor that converts JSON logs or logfmt logs into a clear human-readable format.

Convert your codebase into a single LLM prompt.

Thu, 11 Dec 2025 13:16:46 +0800

Convert your codebase into a single LLM prompt.

Configuring SSH Keys for Multiple GitHub Accounts

Tue, 11 Feb 2025 15:06:00 +0800

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

Running GitHub Actions for Certain Commit Messages

Sun, 11 Oct 2020 23:13:22 +0800

Running GitHub Actions for Certain Commit Messages

Now, whenever I push a wip commit or any commit that contains the word wip, it will be marked as skipped inside of GitHub actions.

jobs:
 format:
 runs-on: ubuntu-latest
 if: "! contains(github.event.head_commit.message, 'wip')"

Any commit that contains [build] will now trigger these jobs, everything else will be skipped.

jobs:
 format:
 runs-on: ubuntu-latest
 if: "contains(github.event.head_commit.message, '[build]')"

Getting Started with GitHub Actions

Mon, 23 Dec 2019 10:16:01 +0800

Getting Started with GitHub Actions

Github on Ricky