shell/结构化命令/判断字符串长度是否为零.sh

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#!/bin/bash
# testing string length
#-n 判断长度是否非零
#-z 判断长度是否为零
val1=testing
val2=''
if [ -n "$val1" ]
then
echo "The string $val1 is not empty"
else
echo "The string $val1 is empty"
fi
if [ -z "$val2" ]
then
echo "The string $val2 is empty"
else
echo "The string $val2 is not empty"
fi
if [ -z "$val3" ]
then
echo "The string $val3 is empty"
else
echo "The string $val3 is not empty"
fi