Linux terms
The operating system underneath almost everything in production
Linux runs the servers, containers, and cloud instances that power most production software. This category covers shell commands, file systems, process management, permissions, networking tools, cron jobs, and the system internals that every backend developer benefits from understanding. Knowing your way around Linux is not optional when something breaks at 2am.
Environment Variables PHP 5.0+
Key-value pairs inherited by child processes — the standard way to pass configuration, credentials, and runtime settings to PHP applications without hardcoding.
2mo ago
linux intermediate
File Descriptors & ulimit PHP 5.0+
File descriptors are integer handles for open files, sockets, and pipes — each process has a limit (ulimit -n), and exhausting them causes 'too many open files' errors.
2mo ago
linux intermediate
Linux Log Files
Log locations, rotation, and analysis tools on Linux — /var/log/ structure, journald, logrotate, and essential log analysis commands.
2mo ago
linux intermediate
Linux Memory Management
How Linux allocates RAM — virtual memory, the page cache, swap, and the OOM killer — and what PHP developers need to know when PHP processes run out of memory.
2mo ago
linux intermediate
Linux Networking Tools PHP 5.0+
Essential tools for diagnosing network issues on Linux servers — ss, netstat, curl, dig, tcpdump, and ping each reveal different layers of connectivity problems.
2mo ago
linux intermediate
Linux Performance Tools
Essential tools for diagnosing CPU, memory, IO, and network performance on Linux — top, htop, vmstat, iostat, perf, strace, and ltrace.
2mo ago
linux intermediate
Linux User & Group Management
Managing users and groups on Linux servers — useradd, usermod, passwd, groups — and best practices for PHP web server user isolation and privilege separation.
2mo ago
linux intermediate
Regex with grep, sed & awk
Three essential Linux text processing tools — grep for filtering lines, sed for stream editing, awk for field-based processing — all using regular expressions.
2mo ago
linux intermediate
Systemd Services & Unit Files
Systemd is the init system managing service lifecycle on modern Linux — unit files define how services start, stop, restart, and depend on each other.
2mo ago
linux intermediate
Bash Scripting bash4 Writing shell scripts in Bash to automate command-line tasks — from simple file operations to complex deployment pipelines.
2mo ago
linux intermediate
Linux Processes PHP 5.0+
Every running program is a process with a PID, memory space, and file descriptors — ps, top, kill, and signals are the essential tools for managing them.
2mo ago
linux intermediate
Shell Pipes & Redirects
Pipes (|) connect stdout of one command to stdin of another; redirects (<, >, >>) send stdin/stdout to files — the foundation of composable Unix command-line workflows.
2mo ago
linux intermediate