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 … Continue reading "How to write a shell script"