In the world of computer programming, it is often necessary to interact with external devices through various ports. One such port that is commonly used is the USB-Serial port. This port allows for communication between a computer and devices such as printers, scanners, and external hard drives. However, when working with these devices in Linux using C, it can be a bit tricky to find the specific attached device to the USB-Serial port. In this article, we will explore the steps and code needed to successfully find the attached device to a USB-Serial port in Linux using C.
First and foremost, we need to understand how the USB-Serial port works in Linux. When a device is connected to the port, it is assigned a device name, also known as a device node. This device node is located in the /dev directory and has the format of "ttyUSBx" where x represents a number. This device node is crucial in identifying the attached device.
Next, we need to write the code that will help us identify the device node of the attached device. This can be done using the opendir() and readdir() functions. These functions allow us to open and read the contents of a directory, in this case, the /dev directory. Once the directory is opened, we can use the readdir() function to loop through all the files in the directory and check for the device node that matches the USB-Serial format.
Once we have identified the device node, we can use the open() function to open the device for reading and writing. This function takes in the device node path and a few flags as parameters. These flags specify the mode in which the device will be opened. In our case, we will use the O_RDWR flag, which allows for both reading and writing to the device.
After successfully opening the device, we can use the read() and write() functions to send and receive data to and from the attached device. These functions take in the file descriptor returned by the open() function as a parameter. It is essential to note that the data being sent and received must be in the correct format for the attached device to understand and respond accordingly.
It is also crucial to handle any errors that may occur during the process of finding and interacting with the attached device. This can be done using the perror() function, which prints out a descriptive error message based on the value of the errno variable.
In conclusion, finding the attached device to a USB-Serial port in Linux using C requires understanding the device node format, writing code to identify the device node, and using the appropriate functions to open, read, and write to the device. With this knowledge and the right approach, interacting with external devices through the USB-Serial port in Linux using C can be a smooth and successful process.
