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#!/bin/bash

# ---- if / elif / else ----
FILE="/etc/hosts"

if [[ -f "$FILE" ]]; then
    echo "$FILE exists and is a regular file"
elif [[ -d "$FILE" ]]; then
    echo "$FILE is a directory"
else
    echo "$FILE does not exist"
fi

# String comparison
USER_INPUT="yes"
if [[ "$USER_INPUT" == "yes" ]]; then
    echo "User agreed"
fi

# Numeric comparison (-eq -ne -lt -le -gt -ge)
COUNT=5
if (( COUNT > 3 )); then
    echo "Count is greater than 3"
fi

# ---- for loop ----
# Over a list
for fruit in apple banana cherry; do
    echo "Fruit: $fruit"
done

# Over a range
for i in {1..5}; do
    echo "Iteration $i"
done

# Over files
for f in /etc/*.conf; do
    echo "Config file: $f"
done

# C-style
for (( i=0; i<3; i++ )); do
    echo "Index $i"
done

# ---- while loop ----
counter=1
while (( counter <= 3 )); do
    echo "Counter: $counter"
    (( counter++ ))
done

# Read file line by line
while IFS= read -r line; do
    echo "Line: $line"
done < /etc/hosts