0340bashshell-scripts.htm

来自「鸟哥LINUX 学习课本」· HTM 代码 · 共 1,372 行 · 第 1/5 页

<tr>
<td>
<center>-x</center>
</td>

<td>
<center>侦测是否为<font color="#3333ff">可执行</font>的属性</center>
</td>
</tr>

<tr>
<td>
<center>-s</center>
</td>

<td>
<center>侦测是否为『<font color="#3333ff">非空白档案</font>』</center>
</td>
</tr>

<tr>
<td>
<center>-u</center>
</td>

<td>
<center>侦测是否具有『 <font color="#3333ff">SUID</font> 』的属性</center>
</td>
</tr>

<tr>
<td>
<center>-g</center>
</td>

<td>
<center>侦测是否具有『 <font color="#3333ff">SGID</font> 』的属性</center>
</td>
</tr>

<tr>
<td>
<center>-k</center>
</td>

<td>
<center>侦测是否具有『 <font color="#3333ff">sticky bit</font> 』的属性</center>
</td>
</tr>

<tr>
<td>4.</td>

<td><font color="#000099">两个档案之间的判断与比较 ；例如<font face="SimSun">『
test file1 -nt file2 </font>』</font></td>
</tr>

<tr>
<td>
<center>-nt</center>
</td>

<td>
<center>第一个档案比第二个档案新</center>
</td>
</tr>

<tr>
<td>
<center>-ot</center>
</td>

<td>
<center>第一个档案比第二个档案旧</center>
</td>
</tr>

<tr>
<td>
<center>-ef</center>
</td>

<td>
<center>第一个档案与第二个档案为同一个档案（ link 之类的档案）</center>
</td>
</tr>

<tr>
<td>5.</td>

<td><font color="#000099">逻辑的『和(and)』『或(or)』</font></td>
</tr>

<tr>
<td>
<center><b><font color="#3333ff" face="SimSun">&amp;&amp;</font></b></center>
</td>

<td>
<center><b><font color="#3333ff">逻辑的 AND 的意思</font></b></center>
</td>
</tr>

<tr>
<td>
<center><b><font color="#3333ff" face="SimSun">||</font></b></center>
</td>

<td>
<center><b><font color="#3333ff">逻辑的 OR 的意思</font></b></center>
</td>
</tr>
</tbody></table>

<p>比较有趣的应该算是 1, 3 这两种种类的判断，尤其是在建立一些 permission
相关的档案时，这个就更重要了！然后那个『<font color="#3333ff">两个档案之间的判断</font>』也是挺有意思的！有空的话不妨去试一试去！还有，那个
<b><font color="#3333ff">&amp;&amp;</font></b>
及 <b><font color="#3333ff">||</font></b> 这两个东西也是很重要的！接着下来，我们要来谈一谈运算符号啰！</p></ul>

<ul>
<li>
<font color="#000099">运算符号简介：</font></li>

<br>在 bash shell scripts 的运算符号的加减乘除是怎样的一回事呀！？谈一谈吧！
<br>&#160;
<table border="1" cols="2" width="600">
<tbody><tr>
<td bgcolor="#ffcccc" width="100">
<center>运算符号</center>
</td>

<td bgcolor="#cccccc" width="500">
<center>代表意义</center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">=</font></center>
</td>

<td>
<center><font face="SimSun">等于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">!=</font></center>
</td>

<td>
<center><font face="SimSun">不等于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">&lt;</font></center>
</td>

<td>
<center><font face="SimSun">小于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">&gt;</font></center>
</td>

<td>
<center><font face="SimSun">大于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-eq</font></center>
</td>

<td>
<center><font face="SimSun">等于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-ne</font></center>
</td>

<td>
<center><font face="SimSun">不等于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-lt</font></center>
</td>

<td>
<center><font face="SimSun">小于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-gt</font></center>
</td>

<td>
<center><font face="SimSun">大于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-le</font></center>
</td>

<td>
<center><font face="SimSun">小于或等于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-ge</font></center>
</td>

<td>
<center><font face="SimSun">大于或等于</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-a</font></center>
</td>

<td>
<center><font face="SimSun">双方都成立（and）</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-o</font></center>
</td>

<td>
<center><font face="SimSun">单方成立（or）</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-z</font></center>
</td>

<td>
<center><font face="SimSun">空字符串</font></center>
</td>
</tr>

<tr>
<td>
<center><font face="SimSun">-n</font></center>
</td>

<td>
<center><font face="SimSun">非空字符串</font></center>
</td>
</tr>