Linux Shell

Find which port the billing service is configured to use. The config lives somewhere under ~/services. Enter the port number as your answer.

Create ~/work/clients/acme/{contracts,invoices,notes} (three folders) and copy ~/templates/invoice.md into the invoices folder.

From ~/logs/app.log, write the number of ERROR lines per day into ~/errors-by-day.txt as lines like “2026-10-17 2”, sorted by date.

Every *.sh file under ~/bin (including subfolders) must be executable by you. Do not change other files.

Add an environment variable API_URL=https://api.acme.example to ~/.zshrc so new shells get it, and export it in the current shell too.

Create an alias gs for “git status” that works now and in future shells (~/.zshrc).

Using ~/data/sales.csv, write total amount per region to ~/report.txt as “REGION TOTAL” lines, highest total first.

~/users.json lists accounts. Write the emails of active users on the pro plan, one per line, into ~/active-pro.txt.

~/cleanup.txt lists files (one per line, relative to ~/media) that must be deleted. Delete exactly those files.

Create an executable script ~/bin/logcount.sh that prints, for every *.log file in the directory given as its first argument, a line “NAME COUNT” where COUNT is the number of lines containing ERROR.

Schedule ~/bin/backup.sh to run every day at 02:30 for your user.

Start a detached tmux session named work with two side-by-side panes titled editor and server. In the server pane, run: ls ~/app

Re-run the long deploy command from your history (it is already there) without retyping it, then save its output to ~/deploy.out. Use Ctrl-R or history expansion.

Something is already listening on port 8080, so the new API cannot start. Find the process, stop it, and enter its name as your answer.

From ~/auth.log write every distinct IPv4 address with a failed password attempt to ~/blocklist.txt, one per line, sorted.

From ~/access.log write the top 3 client IPs by number of 5xx responses to ~/top-5xx.txt as “COUNT IP” lines, highest first (ties: lower IP first).

Write ~/bin/safe-archive.sh: it takes a directory argument, exits with status 2 and prints a usage message to stderr if the argument is missing or not a directory, and otherwise creates DIR.tar.gz next to the directory. Use set -euo pipefail.