Shell's If statement

Today, to use the shell to do some auxiliary work, long time not to use, a little forgotten ...

Here's a summary of today:

1. If the brackets of the If judgment to leave enough space

such as if space [space content space];then

....

....

Fi

2. The condition of the number of judgment, with-eq/-lt/-gt ... And so on to judge

3.if If the judging condition multiple, need to carry on and or not combination judgment remember to use-a-o

For example,

If [condition 1-a condition 2-a Condition 3]

Shell's If statement