At the last stop of our bash learning journey, we will see some sporadic knowledge points. Of course, we have covered many aspects in the previous chapters, but there are many bash features we have not covered. Most of these features are quite obscure, and are mainly useful for programs that integrate bash into Linux distributions. However, there are some features read the whole passage

In the previous chapter, we looked at how the shell handles strings and numbers. At present, the data types we see are called scalar variables in the circle of computer science; That is, a variable can only contain one value. In this chapter, we will look at another data structure called array, which can store multiple values. Arrays are a feature of almost all programming languages. shell … read the whole passage

All computer programs are used to deal with data. In previous chapters, we focused on processing file level data. However, many programming problems need to be solved with smaller data units, such as strings and numbers. In this chapter, we will look at several shell functions for manipulating strings and numbers. The shell provides various string operations read the whole passage

In this final chapter on process control, we will look at another kind of shell loop construction. The for loop is different from the while and until loops because it provides a way to process sequences. This is very useful when programming. So in the bash script, The for loop is a very popular construct. Implement a fo read the whole passage

At present, our program lacks the ability to receive and process command line options and parameters. In this chapter, we will explore some shell capabilities that allow programs to access command line content. Accessing the command line shell provides a set of variables called positional parameters, which contains all the independent words in the command line. These variables are given from 0 to 9 to read the whole passage

In this chapter, we will continue to look at the process control of the program. In Chapter 28, we built some simple menus and created program logic to deal with various user choices. To this end, we used a series of if commands to identify which possible option has been selected. This type of structure often appears in the program, so much so that many programs read the whole passage

As our scripts become more and more complex, when the script runs incorrectly and the execution results are unexpected, we should check the reasons. In this chapter, we will look at some common error types in scripts, and introduce some useful techniques to track and eliminate problems. Syntax Error A common type of error is syntax. The syntax error involves some sh read the whole passage