BASH 检查变量中是否存在
我正在编写一个用于映射网络驱动器的脚本。但是，我们只想在计算机具有特定 IP 地址时尝试映射驱动器。下面列出的是我们正在尝试运行的代码片段。
#!/bin/sh
IP="dig $HOSTNAME +short"
if [ $IP == *10.130.10.* ]; then
mount drive commands here
fi
if [ $IP == *10.130.11.* ]; then
mount drive commands here
fi
我无法让 IP 检查正常工作。有没有更好的方法来检查变量是否包含字符串（在本例中是 IP 地址的一部分）？
此帖子中列出的信息没有帮助，因为它不起作用。
I am working on a script that will be used to map network drives. However, we only want to attempt to map the drive if the machine has a particular IP address. Listed below is a code snippet that we are trying to get working.
#!/bin/sh
IP="dig $HOSTNAME +short"
if [ $IP == *10.130.10.* ]; then
mount drive commands here
fi
if [ $IP == *10.130.11.* ]; then
mount drive commands here
fi
I am not able to get the check for IP to work. Is there a better way to check to see if a variable contains a string, in this case part of an IP address?
The information listed in this posting was not helpful since it did not work.
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你的问题有一个“bash”标签，但 shebang 说的是 /bin/sh。您实际上想使用哪个？
事实上，首先要做的事情。您设置 IP 的方式不起作用，因为它从不运行 dig 命令；您需要反引号或
$( )来执行此操作：现在，进行测试；有很多种方法可以做到这一点。这应该适用于所有 shell：
请注意，如果两个子网的挂载命令相同，则可以使用
*10.130.10.*|*10.130.11.*)作为匹配模式。如果您实际上使用的是 bash，则可以使用其
[[ ]]条件表达式来进行匹配，就像您的方式一样：如上所述，如果挂载命令相同，您可以这样做带有
if [[ "$IP" == *10.130.10.* || 的单个条件"$IP" == *10.130.10.* ]];然后。另外，在这种特殊情况下，$IP周围的双引号实际上并不是必需的，但我总是养成双引号变量的习惯，除非有理由不这样做。You have a "bash" tag on the question, but the shebang says /bin/sh. Which do you actually want to use?
Actually, first things first. The way you're setting IP doesn't work, since it never runs the dig command; you need either backquotes or
$( )to do that:Now, for the test; there are a number of ways to do it. This should work in all shells:
Note that if the mount commands are the same for the two subnets, you can use
*10.130.10.*|*10.130.11.*)as the pattern to match.If you're actually using bash, you can use its
[[ ]]conditional expression to do the matching more like how you had it:As above, if the mount commands are the same, you can do a single conditional with
if [[ "$IP" == *10.130.10.* || "$IP" == *10.130.10.* ]]; then. Also, the double-quotes around$IParen't actually necessary in this particular case, but I always make a habit of double-quoting variables unless there's a reason not to.