Learn shell scripting and command‑line fundamentals. From variables and quoting to pipelines and robust scripting practices.
Your first shell script and running commands.
Setting, exporting, and scoping; positional params.
Single vs double quotes, command/parameter/brace expansion.
String ops, arrays, and slicing.
if/elif/else, case, and test/[ ]/[[ ]] syntax.
for/while/until, loop control, and reading files safely.
Defining functions, return codes, and local variables.
stdin/stdout/stderr, >, >>, <, here-docs, and process substitution.
Pipelines with grep/sed/awk/sort/uniq/xargs.
Wildcards, extglob, nullglob, and find predicates.
$?, set -euo pipefail, traps, and robust scripts.
.bashrc/.profile, PATH, and exporting vars.
Shebang, permissions, shellcheck, and style.
bg/fg, jobs, nohup, disown, and signals.
cron, at, systemd timers overview.
Parameter expansion patterns and defaults.