Checking Syntax in Bash
This article discusses methods for checking Bash scripts for syntax problems without running the script.
Syntax errors are caused by some grammatical or spelling mistakes in the code. In modern compilers of other programming languages, the compiler highlights such errors even before running the program.
This is not the case in Bash scripts, since Bash is a command line interpreter. Hence, we need to check for syntax errors separately.
There are different techniques to check for syntax issues as shown below.
Using the Online ShellCheck Editor
There is an online tool Shell Check that can check the syntax errors of the script.
In the above picture, there are two separate windows. One is the code editor, and the lower part shows a list of errors and warnings in the code by specifying line numbers.
ShellCheck Editor is a very useful tool for both beginner and expert programmers as it detects minor to advanced issues in the code before executing it.
Use bash -n (noexec mode) command
You can also use the -n flag (noexec) with the bash command to check for errors in your scripts.
bash -n [script-name]
This will just read all the commands in the script and check for errors without running them. If there are errors in the commands, it will show them; otherwise, no output will be shown.
For example, consider the following script.
请注意, we have missed the end of the if statement (i.e., used fi instead of if). So, it will give an error.
Using sh command
Another command to check for syntax errors is:
sh -n [script-name]
We will run the command for the same script discussed in the previous section and check for errors.
For reprinting, please send an email to 1244347461@qq.com for approval. After obtaining the author's consent, kindly include the source as a link.
Related Articles
Check if input parameter exists in Bash
Publish Date：2025/03/21 Views：191 Category：OPERATING SYSTEM
-
When we create a Bash script, we may want to use parameters in our script to run successfully. Therefore, we need to create a script to check the number of input parameters used by the user in the script. All of this prevents unexpected beh
Run batch (.bat) files in CMD
Publish Date：2025/03/20 Views：155 Category：OPERATING SYSTEM
-
This article will show you how to use CMD to run a batch file.bat. There are three ways to run a batch file. Let us discuss them in the following sections. Run batch (.bat) files in CMD by directly clicking on them This way you can just go
Changing CMD text color using batch script
Publish Date：2025/03/20 Views：172 Category：OPERATING SYSTEM
-
This article will first discuss the basic concepts of batch scripts or batch files. After introducing the Batch script, let's discuss how to use the Batch script to change the text color of CMD every second. Batch script or file A batch scr
Batch set command timeout
Publish Date：2025/03/20 Views：50 Category：OPERATING SYSTEM
-
This article will first discuss the concept of timeout command in batch scripting. After that, we will discuss setting timeout command for any other command. Timeout command in batch script A timeout is a utility that pauses or delays for a
Batch merge XML files
Publish Date：2025/03/20 Views：101 Category：OPERATING SYSTEM
-
This article will first discuss and understand the XML file format. After that, we will discuss merging two or more XML files into one file using batch commands and scripts. XML File XML, also known as Extensible Markup Language, is a marku
Run .exe file from command prompt using batch script
Publish Date：2025/03/20 Views：77 Category：OPERATING SYSTEM
-
This article will show you how to use a batch (.bat) script to run a .exe type file. You can use two different commands to achieve this. Let’s discuss each method in the following sections. Run .exe file from command prompt using title an
Deleting files older than N days using batch script
Publish Date：2025/03/20 Views：57 Category：OPERATING SYSTEM
-
In this article, we will use a batch script to delete files older than N days. Deleting files older than N days using batch script The general format of the code to perform this task is shown below. FORFILES /p "D:\DIRECTORY" /S /M *.* /D -
Deleting files using batch script
Publish Date：2025/03/20 Views：178 Category：OPERATING SYSTEM
-
This article will demonstrate how to delete files using a batch script. Deleting files using batch script Generally, we can easily delete files by clicking on delete or pressing the delete button on the keyboard. But in Batch, we have to fo
Concatenate multiple files using batch script
Publish Date：2025/03/20 Views：195 Category：OPERATING SYSTEM
-
In this article, we will see how to concatenate multiple files into one file. Concatenate multiple files using batch script The general format of the commands we will use is shown below. type FileONE.txt FileTWO.txt ConcatFile.txt There are
