下面是一个例子，它使用的所有文件测试操作：
假设一个变量的文件保存现有文件名"/var/www/yiibai/unix/test.sh"，其大小为100字节，读，写和执行权限：
#!/bin/sh file="/var/www/yiibai/unix/test.sh" if [ -r $file ] then echo "File has read access" else echo "File does not have read access" fi if [ -w $file ] then echo "File has write permission" else echo "File does not have write permission" fi if [ -x $file ] then echo "File has execute permission" else echo "File does not have execute permission" fi if [ -f $file ] then echo "File is an ordinary file" else echo "This is sepcial file" fi if [ -d $file ] then echo "File is a directory" else echo "This is not a directory" fi if [ -s $file ] then echo "File size is zero" else echo "File size is not zero" fi if [ -e $file ] then echo "File exists" else echo "File does not exist" fi
这将产生以下输出结果：
File has read access File has write permission File has execute permission File is an ordinary file This is not a directory File size is zero File exists
记下以下几点：
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运算符和表达式之间必须有空格，例如2+2是不正确的，它应该写成2 + 2。
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if...then...else...fi 语句在下一章节中已经解释的决策声明。
