linux的test在脚本中怎么用

在Linux脚本中，test 命令通常用于进行条件测试

1. 数值比较：

#!/bin/bash
num1=10
num2=20

if test $num1 -lt $num2; then
  echo "Number 1 is less than Number 2"
else
  echo "Number 1 is not less than Number 2"
fi

2. 字符串比较：

#!/bin/bash
str1="hello"
str2="world"

if test "$str1" != "$str2"; then
  echo "String 1 is not equal to String 2"
else
  echo "String 1 is equal to String 2"
fi

3. 文件测试：

#!/bin/bash
file="/path/to/your/file"

if test -e "$file"; then
  echo "File exists"
else
  echo "File does not exist"
fi

4. 逻辑操作：

#!/bin/bash
num1=10
num2=20

if test $num1 -lt $num2; then
  if test $num1 -eq $num2; then
    echo "Number 1 is less than and equal to Number 2"
  else
    echo "Number 1 is less than Number 2"
  fi
else
  if test $num1 -eq $num2; then
    echo "Number 1 is greater than and equal to Number 2"
  else
    echo "Number 1 is greater than Number 2"
  fi
fi

注意：在脚本中使用 test 命令时，建议使用双方括号 [[ ]] 进行条件测试，因为它提供了更强大的功能和更好的可读性。例如：

#!/bin/bash
num1=10
num2=20

if [[ $num1 -lt $num2 ]]; then
  echo "Number 1 is less than Number 2"
else
  echo "Number 1 is not less than Number 2"
fi