Bash Get Started

Open a terminal

• Linux: open "Terminal"; Bash is usually the default shell.
• macOS: open Terminal; the default shell is zsh, and bash starts Bash (macOS ships an old 3.2; install a current one with Homebrew: brew install bash).
• Windows: install WSL (wsl --install) and open Ubuntu.

Check the version with bash --version.

Your first script

Create hello.sh:

#!/usr/bin/env bash
echo "Hello from a script"

The first line, the shebang, tells the system which interpreter runs the file. Make it executable and run it:

chmod +x hello.sh
./hello.sh

The example below creates a script, makes it executable and runs it, all from Bash:

cat > hello.sh <<'EOF'
#!/usr/bin/env bash
echo "Hello from a script"
echo "This script is called $0"
EOF
chmod +x hello.sh
./hello.sh
ls -l hello.sh | cut -c1-10

Hello from a script
This script is called ./hello.sh
-rwxrwxr-x

./ is needed because the current directory isn't on your PATH (a safety feature).