运行一个 bash for 循环零次

Question

对于 c 风格的语言 for 循环以下执行零次：

for (int myvar = 0; myvar <= -3; myvar++) {
   printf("hi")
}

bash 将通过 -1

执行四次循环

for j in {0..-3}; do echo 'hi'; done

hi
hi
hi
hi

下面会执行一次

for j in {1..4..0}; do echo 'hi'; done

hi

那么如何避免在不注释掉整个循环的情况下执行循环呢？我想通过循环索引中的变量来控制它：

first=0
last=-3
step=1
for j in {$first..$last..$step}; do echo 'hi'; done

hi

Answer 1

for ((j=0; j<=-3; j++)); do
    echo hi
done

for ((j=first; j<=last; j+=step)); do
    echo hi
done

Run a bash for loop zero times