Scripting with Zsh on macOS Tahoe
While the Getting Started with macOS Tahoe guide introduces a basic script, Zsh offers a robust set of features for complex automation. This guide dives deeper into the syntax and capabilities of Zsh scripting.
The Shebang
Every Zsh script on macOS Tahoe should start with the "shebang" line. This tells the system which interpreter to use.
#!/bin/zshVariables
Variables in Zsh do not require data type declarations.
#!/bin/zsh
# String variable
OS_NAME="macOS Tahoe"
# Integer variable
VERSION=26
echo "Running on $OS_NAME version $VERSION"Conditionals
Zsh uses <a href='/%20...%20'> ... </a> for conditional tests, which is more powerful and safer than the older [ ... ] syntax found in generic sh.
#!/bin/zsh
FILE="config.txt"
if <a href='/%20-f%20%22%24FILE%22%20'> -f "$FILE" </a>; then
echo "$FILE exists."
else
echo "$FILE does not exist. Creating it..."
touch "$FILE"
fiCommon Test Operators
-f: File exists and is a regular file.-d: Directory exists.-z: String is empty.-n: String is not empty.
Loops
Automate repetitive tasks using loops.
For Loop
Iterate over a list of items or files.
#!/bin/zsh
# Rename all .txt files to .md
for file in *.txt; do
mv "$file" "${file%.txt}.md"
doneHandling Arguments
Scripts can accept input from the command line.
$1,$2, etc.: Positional arguments.$#: Number of arguments passed.$@: All arguments as a list.
#!/bin/zsh
if <a href='/%20%24%23%20-eq%200%20'> $# -eq 0 </a>; then
echo "Usage: $0 <name>"
exit 1
fi
echo "Hello, $1!"User Input
You can pause the script to ask for user input using read.
#!/bin/zsh
read "response?Do you want to continue? (y/n) "
if <a href='/%20%22%24response%22%20%3D~%20%5E%5BYy%5D%24%20'> "$response" =~ ^[Yy]$ </a>; then
echo "Continuing..."
else
echo "Aborting."
exit 0
fi