Linux & the Command Line
Own the terminal that every infrastructure job lives in.
Servers don't have a mouse. Before Terraform or the cloud make any sense, you need to move through a Linux box without thinking — find files, follow logs, fix permissions, and chain small tools into answers. This track drops you into a real shell and builds that fluency one hands-on lesson at a time, so the command line stops being scary and starts being your fastest tool.
By the end, you can
- Move around the filesystem and inspect anything — no GUI, no hesitation
- Chain tools with pipes to answer real questions about a running system
- Read an ls -l, fix permissions and ownership, and unstick the execute bit
- Cut, search, and reshape text and logs with grep, sed, awk, find, and xargs
- Find what's hogging a server, read its logs under pressure, and add a disk without breaking the boot
What's inside
Where this track goes
The first lessons are free — no card. Pro unlocks the production depth that turns this into a job-ready skill.
Free — you can do this
Free0 / 3 free lessons complete
Navigate the filesystem
ls, cd, cat, and the hidden-dotfile convention every box assumes you know.
Pipes & filters
Compose small tools with | — grep, wc, sort — the Unix mindset.
Read the manual
man, man | grep, apropos/whatis and sections — look anything up without a browser.
Pro — what you unlock next
ProRedirection & streams
stdout vs stderr, 2>&1 (and why order matters), /dev/null, tee, and process substitution.
Files, links & inodes
Safe mkdir/cp/rm, stat and inodes, hard links vs symlinks, and the release-symlink swap.
Find files & search trees
find by name/type, grep -r through contents — names vs contents.
Permissions & ownership
Read an ls -l mode, chmod (symbolic + octal), and fix the execute-bit gotcha.
Transform text
sed substitution, awk columns, and cut / sort | uniq -c / tr in a pipeline.
Bulk operations
xargs (-I {}, NUL-safe find -print0 | xargs -0) to act on whole file sets.
Archives & compression
tar create/list/extract, --exclude, gzip levels, and dated, checksummed backups.
fstab & mounts
findmnt, the six fstab fields, adding a disk by UUID with nofail, and fixing a line before it breaks the boot.
Disk & system health
df, du, find big files, free vs cgroup limits, load and top processes, a one-line report.
Processes & top
Read top's summary, catch CPU and memory hogs, stop a runaway with signals, and renice instead of kill.
Reading logs
/var/log, tail and grep by level and time window, SSH brute force in auth.log, zgrep, tail -f, journalctl.
Environment & PATH
export and inheritance, per-command variables, PATH lookup, ~/bin, aliases vs functions.
Log-triage capstone
Build one pipeline that finds the worst-offending endpoint in a real log.
Ready to start?
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