shell 比较两个字符串
比较两个字符串是否相等的办法是： if [ “$test”x = “test”x ]; then 这里的关键有几点： 1 使用单个等号 2 注意到等号两边各有一个空格：这是unix shell的要求 3 注意到”$test”x最后的x，这是特意安排的，因为当$test为空的时候，上面的表达式就变成了x = testx，显然是不相等的。而如果没有这个x，表达式就会报错：[: =: unary operator expected
How to write a shell script
How to write a shell scriptIntroductionA shell is a command line interpretor. It takes commands and executes them. As such, it implements a programming language. The Bourne shell is used to create shell scripts — ie. programs that are interpreted/executed by the shell. You can write shell scripts with the C-shell; however, this is not […]