Functions

KSH basic function with parameter

#!/bin/ksh
function greet {
    typeset name=$1
    print "Hello, $name!"
}

greet "World"

KSH function that returns a value

#!/bin/ksh
function add {
    typeset a=$1 b=$2
    typeset result=$((a + b))
    print $result
}

sum=$(add 5 3)
print "Sum is: $sum"

KSH function with local variables and cleanup

#!/bin/ksh
function process_file {
    typeset filename=$1
    typeset temp_dir="/tmp/processing"
    typeset backup_file="${filename}.backup"
    
    mkdir -p "$temp_dir"
    cp "$filename" "$backup_file"
    print "Processing $filename in $temp_dir"
    rm -rf "$temp_dir"
}

process_file "data.txt"

KSH function with error handling and return codes

#!/bin/ksh
function safe_divide {
    typeset a=$1 b=$2
    if (( b == 0 )); then
        print "Error: Division by zero" >&2
        return 1
    fi
    print $((a / b))
}

result=$(safe_divide 10 2)
print "Result: $result"

safe_divide 10 0

KSH function with default parameter values

#!/bin/ksh
function greet {
    typeset name=${1:-"World"}
    typeset greeting=${2:-"Hello"}
    print "$greeting, $name!"
}

greet
greet "Alice"
greet "Bob" "Hi"

KSH function that accepts variable number of arguments

#!/bin/ksh
function sum {
    typeset total=0
    for num in "$@"; do
        total=$((total + num))
    done
    print $total
}

result=$(sum 1 2 3 4 5)
print "Sum: $result"