If you’re working with shell scripts, you may have encountered the error “Syntax Error Near Unexpected Token ‘(‘” when trying to run a script with the
rm command. This error is usually caused by the shell not recognizing the
extglob syntax, a feature that allows for advanced pattern matching. In this article, we will discuss how to fix this error and successfully run your shell script.
To fix the "Syntax Error Near Unexpected Token ‘(‘" when running a shell script with the
rm command, you can either enable the
extglob option in your script by adding
shopt -s extglob at the beginning, or use the
GLOBIGNORE variable to exclude files with a specific extension from being removed.
Understanding the Error
Before we delve into the solution, it’s important to understand the cause of the error. The
!(*.sh) syntax is part of the
extglob feature in Bash. This syntax allows you to match all files except those with a specific extension, in this case,
extglob is not enabled by default in shell scripts, causing the shell to throw a syntax error when it encounters the
One solution to this error is to enable the
extglob option in your shell script. You can do this by adding the following line at the beginning of your script:
shopt -s extglob
shopt command is used to toggle the values of shell options. The
-s option stands for “set”, meaning that it enables the option that follows. In this case, it enables
Here’s an updated version of your
shopt -s extglob
rm !(*.sh) -rf
rm command is used to remove files or directories. The
-R option tells
rm to remove directories and their contents recursively, and the
-f option forces deletion of files without prompting for confirmation.
If you don’t want to enable
extglob, you can use the
GLOBIGNORE variable to achieve the same result.
GLOBIGNORE is a bash variable that defines the patterns that should be ignored during pathname expansion.
Here’s an example:
rm -rf *
In this case, the
GLOBIGNORE variable is set to exclude files with the
.sh extension from glob expansion, and then the
rm command is used to remove all remaining files.
Both of these solutions should allow you to remove all files except those with the
.sh extension when running your shell script. Remember to always be careful when using the
rm command, especially with the
-f options, as it can permanently delete files.
A shell script is a computer program written in a scripting language that is interpreted by a shell, such as Bash. It contains a series of commands that are executed in sequence.
To run a shell script, you need to make it executable using the
chmod command. For example, you can use
chmod +x script.sh to make the script named "script.sh" executable. Then, you can run it by typing
./script.sh in the terminal.
There are several ways to debug a shell script. One common approach is to use the
set -x command at the beginning of your script to enable debugging mode. This will print each command and its arguments before executing them. You can also use the
echo command to print variable values or intermediate results to the terminal for debugging purposes.
You can pass arguments to a shell script by providing them after the script name when running it. For example, if your script is named "script.sh" and you want to pass two arguments, you can run it like this:
./script.sh arg1 arg2. Inside the script, you can access these arguments using positional parameters like
You can redirect the output of a shell script to a file using the
> operator. For example, if you want to redirect the output to a file named "output.txt", you can run the script like this:
./script.sh > output.txt. This will overwrite the contents of the file. If you want to append the output to an existing file, you can use the
>> operator instead:
./script.sh >> output.txt.