for 循环

遍历列表

for fruit in apple banana orange
do
  echo "I like $fruit"
done

遍历文件

for file in *.txt
do
  echo "Processing $file"
  cp "$file" backup/
done

 数字范围（使用 seq 或 {start..end}）

# 1到5
for i in {1..5}
do
  echo "Number: $i"
done

# 步长2（需要 Bash 4+）
for i in {1..10..2}
do
  echo "Odd: $i"
done

# 使用 seq
for i in $(seq 1 5)
do
  echo "Seq: $i"
done

C 语言风格 

for ((i=0; i<5; i++))
do
  echo "Index: $i"
done