S5 Recap: Make The Shell Work For You

Session: S5

What You Built

~/scripts/maker-report.sh accepts one title, collects live system facts, and writes ~/src/pages/maker-report.md. build-website turns that Markdown into maker-report.html.

Four Models

bash maker-report.sh -> start Bash explicitly; execute permission is not needed
./maker-report.sh    -> run the file here; requires execute permission and a shebang

"My Maker Report" -> $1 -> report_title="$1" -> "$report_title" -> one value

{
  many commands
} > file

many stdout streams -> one generated file

maker-report.sh -> maker-report.md -> build-website -> maker-report.html

Details Worth Remembering

• .sh is a filename convention, not executable permission.
• . means the current directory, so ./maker-report.sh names the file here.
• In chmod u+x, u is the user who owns the file and x is execute permission.
• #!/bin/bash tells Linux to use Bash when the file is run directly.
• Shell assignment has no spaces around =.
• Quotes are needed both when passing a multi-word argument and when expanding it.
• Triple backticks open and close the report’s plain-text code block.
• bash -x reveals commands as Bash runs them and keeps its trace on stderr.

Repeat The Safe Workflow

cd ~/scripts
bash -n maker-report.sh
./maker-report.sh "Fresh Report"
cat ~/src/pages/maker-report.md
build-website

Optional Reinforcement

Three sequential extensions follow the live objectives: add uptime, run the script from another directory, and preserve it in Git.

The self-study guide also contains an unscored shell-options appendix. It demonstrates set -u with an unset $1, then set -e with one standalone failed command. These options reveal failures; they do not replace input checks or explicit error handling.

Can You Explain This?

• Why can bash maker-report.sh run a non-executable text file?
• What does ./ mean?
• What does chmod u+x change?
• What does the #!/bin/bash first line tell Linux?
• Why is report_title = "$1" wrong?
• Why do both the caller and the script use quotes?
• How does one > capture output from every command inside { ... }?

Full Autonomy

Use S5 Self-Study Guide: Make The Shell Work For You for every exercise, the complete script, reset steps, and symptom-based recovery.