array-new.txt

#!/usr/local/bin/bash
SCRIPT_NAME="${0##*/}"
warn() {
  info "[WARNING]: ${1}" >&2
}

warn_pause() {
  warn "${1}"
  sleep 2
}

error() {
  info "[ERROR]: ${1}" >&2
}

infom() {
  local VERBOSE; VERBOSE="$(context_get-option "VERBOSE")"
  if hash ts 2>/dev/null && [[ "${VERBOSE}" -eq 1 ]]; then
    echo "${SCRIPT_NAME}: ${1}" | TZ=utc ts '%Y-%m-%dT%.T' >&2
  else
    echo "${SCRIPT_NAME}: ${1}" >&2
  fi
}

info() {
        echo "${SCRIPT_NAME}: ${1}"
}

info "本身命令的输出是换行的的 可以直接读取每一行,然后打印或者执行执行对应命令"
kubectl get ns --no-headers | while read -r ns _ _; do
    echo "will delete the namespace: $ns"
done

awk 'BEGIN{while (a++<50) s=s "-"; print s,"readarry method",s}'
info "下面就是每行一个namespace,我使用readarray的方法"
readarray -t ns_list < <(kubectl get ns --no-headers | awk '{print$1}')
for ns in "${ns_list[@]}";  do
    echo "will delete the namespace: $ns"
done

awk 'BEGIN{while (a++<50) s=s "-"; print s,"one line",s}'
info "the next command one line get ns"
echo "kubectl get namespace -o jsonpath='{.items[*].metadata.name}'"
#kubectl get namespace -o jsonpath='{.items[*].metadata.name}'
awk 'BEGIN{while (a++<50) s=s "-"; print s,"看看对一行输出循环",s}'
echo "the next command one line get ns .Then for loop it testing"
echo "赋值为数据的时候,读取的文件内容是否换行也很重要 ,如果没有换行,是一行输入可以直接用 for i in $(command);do echo $i;done"
for ns in $(kubectl get namespace -o jsonpath='{.items[*].metadata.name}'); do
    echo "will delete XXX the namespace: $ns"
done


awk 'BEGIN{while (a++<50) s=s "-"; print s,"compare下赋值的()",s}'
namespace_list=$(kubectl get namespace -o jsonpath='{.items[*].metadata.name}')
echo "the namespace_list: $namespace_list"
echo "The number of array ${#namespace_list[@]}"
echo "use ()直接赋值 有告警"
namespace_list=($(kubectl get namespace -o jsonpath='{.items[*].metadata.name}'))
echo "the namespace_list: $namespace_list"
echo "The number of array ${#namespace_list[@]}"
#${#array[@]}数组元素的个数： 利用这可以去做循环

for((i=0;i<${#namespace_list[@]};i++));do
    echo "the namespace_list: ${namespace_list[i]}"
done



 echo "#列出所有键值对 key是数字下标"
 for key in "${!namespace_list[@]}"
 do
     echo "${key} -> ${namespace_list[$key]}"
 done