Linux & Bash for Developers

What is Linux and why developers use it

Linux kernel, distributions, GNU/Linux, why Linux for development, Windows vs Linux differences, open-source ecosystem

Linux file system hierarchy explained

FHS standard, root directory, /etc /var /usr /home /tmp /bin, absolute vs relative paths, mount points

How to navigate directories in Linux terminal

cd, pwd, ls flags, pushd popd, tab completion, directory shortcuts, hidden files

Creating, copying, moving, and deleting files in Linux

touch, mkdir -p, cp flags, mv, rm -rf, wildcards, rename patterns, file vs directory operations

Linux file permissions and chmod explained

read write execute bits, user group other, octal notation, chmod symbolic mode, chown, sudo, permission denied errors

How to read and view files in Linux terminal

cat, less, more, head, tail, tail -f, file sizes, wc, viewing binary files

grep command tutorial for searching files

grep syntax, -i -v -r -n -c flags, regex basics, egrep, fixed strings, grep with pipes, color output

How to use pipes and redirection in Bash

pipe operator, stdin stdout stderr, >, >>, 2>, 2>&1, /dev/null, tee command, command chaining

sed command for find and replace in Linux

sed syntax, s command, g flag, -i in-place editing, address ranges, delete lines, print specific lines, regex in sed

awk command tutorial for text processing

awk syntax, field separator, NR NF built-ins, print fields, conditionals in awk, BEGIN END blocks, sum and aggregate

How to write your first Bash script

shebang line, script permissions, script execution, bash vs sh, comments, exit codes, script structure

Bash variables and how to use them

variable assignment, quoting rules, environment variables, readonly, unset, command substitution, arithmetic, special variables $0 $1 $#

Bash if else and conditional statements

if elif else syntax, test command, [ ] vs [[ ]], string comparison, numeric comparison, file tests -f -d -e, && || operators

Bash loops: for while and until explained

for loop syntax, C-style for loop, while loop, until loop, loop control break continue, looping over files, seq command, loop over array

Bash functions: how to write reusable code

function syntax, local variables, return values, function arguments, sourcing scripts, libraries, recursive functions

How Linux processes work: PID, parent, and lifecycle

process definition, PID, PPID, fork-exec model, process states, init/systemd, zombie processes, orphan processes

Killing and signaling processes in Linux

kill command, SIGTERM SIGKILL SIGHUP SIGINT, kill -9 vs graceful shutdown, pkill killall, signals in scripts, trap command

How to monitor CPU and memory usage in Linux

top, htop, ps aux sorting, free command, vmstat, uptime, load average, memory types RSS VSZ, /proc filesystem

Background jobs and job control in Bash

background with &, jobs command, fg bg, nohup, disown, screen tmux overview, Ctrl+Z, process groups

How to check disk usage in Linux with df and du

df -h output, du -sh, find by size, disk inode limits, lsof for open files, ncdu, checking what fills disk

Linux networking commands every developer needs

ip addr, ifconfig, ping, traceroute, netstat, ss, hostname, /etc/hosts, DNS lookup with dig and nslookup

SSH tutorial: connect to remote servers securely

SSH client usage, key pair authentication, ssh-keygen, ssh-copy-id, ~/.ssh/config, port forwarding, ProxyJump, SSH agent

Transferring files with scp and rsync

scp syntax, rsync flags -avz, rsync --delete, dry run, bandwidth limit, partial transfers, rsync over SSH, exclude patterns

curl and wget for HTTP requests from terminal

curl GET POST, headers, authentication, follow redirects, output to file, wget recursive download, API testing with curl, JSON payloads

How to use firewall and iptables basics on Linux

iptables concepts, ufw for Ubuntu, allow deny rules, checking firewall status, opening ports, blocking IPs, persistent rules

Bash arrays and associative arrays explained

indexed arrays, array assignment, array access, array iteration, array length, associative arrays, declare -A, array slicing

Bash error handling with set -e, set -u, and traps

set -e exit on error, set -u undefined variables, set -o pipefail, set -x debug mode, trap ERR, || true pattern, defensive scripting

Cron jobs: how to schedule tasks in Linux

crontab syntax, minute hour dom month dow fields, crontab -e, system cron vs user cron, /etc/cron.d, CRON_TZ, common schedule examples, cron logging

Environment variables and .env files in Linux

export, env, printenv, .env file pattern, source command, dotenv in scripts, /etc/environment, profile vs bashrc vs bash_profile, secrets management basics

How to write production-ready Bash scripts

script header conventions, argument parsing with getopts, usage function, input validation, logging levels, locking with flock, idempotent scripts, shellcheck