How to use Go language for file operations?
With the development of the Internet, the generation and processing of large amounts of data have become routine matters in daily work. Under such circumstances, file operations are undoubtedly an essential skill for programmers.
As a simple and efficient programming language, Go language has excellent performance in file operations. With the powerful features of the Go language, you can easily perform operations such as reading, writing, and modifying files. Let's take a closer look at how to use the Go language for file operations.
- Reading files
Go language provides two ways to read files, one is based on cache bufio.Scanner, and the other is based on streaming os.File. Let’s look at the cache-based approach first.
First, we need to open a file, you can use the os.Open() function, the code is as follows:
file, err := os.Open("filename.txt") if err != nil { log.Fatal(err) }
When opening a file, you need to pay attention to exception handling. If the file does not exist or there is an error opening the file, the program will throw a panic and output an error message. At this time, we can use the log.Fatal() function to print the error message and exit the program.
Next, we can use the bufio.NewScanner() function to read the file. The code is as follows:
scanner := bufio.NewScanner(file) for scanner.Scan() { fmt.Println(scanner.Text()) // 输出每行文本内容 } if err := scanner.Err(); err != nil { // 判断是否读取到文件尾 log.Fatal(err) }
The scanner.Scan() function in the code can scan each line of text in the file and store it in scanner.Text(). After the loop completes, if the file has not reached the end of the file, an error will be thrown.
Another stream-based reading method is slightly different. The usage is as follows:
file, err := os.Open("filename.txt") if err != nil { panic(err) } defer file.Close() reader := bufio.NewReader(file) for { line, err := reader.ReadString(' ') if err == io.EOF { break } else if err != nil { panic(err) } fmt.Print(line) }
After the file is read, we need to ensure that the file is closed, which can be achieved through the defer keyword. I won’t go into details here.
- Writing of files
In the Go language, the writing operation of files is also very simple. We can use the os.Create() function and the io.WriteString() function to achieve this.
First, we need to open a file and prepare to write data:
file, err := os.Create("filename.txt") if err != nil { panic(err) } defer file.Close()
Next, we can write data through the io.WriteString() function:
_, err = io.WriteString(file, "Hello World! ") if err != nil { panic(err) }
- File copying
src, err := os.Open("src.txt") if err != nil { panic(err) } defer src.Close() dst, err := os.Create("dst.txt") if err != nil { panic(err) } defer dst.Close() _, err = io.Copy(dst, src) if err != nil { panic(err) }
- Renaming and deleting files
err := os.Rename("oldname.txt", "newname.txt") if err != nil { panic(err) }
err := os.Remove("filename.txt") if err != nil { panic(err) }
The above is the detailed content of How to use Go language for file operations?. For more information, please follow other related articles on the PHP Chinese website!

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