bash：遍历整数数组并避免使用值

Question

我想在shell脚本中执行此操作：

valueToAvoid = [1, 5, 30]
for i in alist
  if i not in valuesToAvoid then
    doSomething
  endif
endfor

有人可以帮忙吗？

Answer 1

如果你有bash4，你可以将你的禁用值放在一个关联数组中：

declare -A avoid
for val in 1 5 30; do avoid[$val]=1; done

for val in {0..99}; do
  if ! [[ ${avoid[$val]} ]]; then
    # Whatever
  fi
done

另一种方法是使用例如grep扫描要避免的值。这可能效率较低，但不需要bash 4功能：

avoid=(this that "the other")
# Avoided values, one per line. I could have done this with a here-doc,
# but sometimes it's useful to convert an array to a sequence of lines
avoid_lines=$(printf %s\\n "${avoid[@]}")

for val in one "the other" two; do
  if ! grep -qFx -e"$val" <<<"$avoid_lines"; then
    # Whatever
  fi
done