In Go, the os/exec package provides functionality for executing external commands. This allows you to run shell commands and interact with the command’s standard input, output, and error streams.

Using os/exec

To use the os/exec package, you first need to import it in your Go code:

import "os/exec"

Running a Command

You can execute a command using the Command function from the os/exec package:

cmd := exec.Command("ls", "-l")

In this example, we’re running the ls -l command.

Handling Output

To capture the output of the command, you can use the Output function:

output, err := cmd.Output()
if err != nil {
    fmt.Println(err)
}
fmt.Println(string(output))

This code captures the output of the command and prints it to the console.

Handling Input

You can also provide input to the command’s standard input stream:

cmd := exec.Command("cat")
stdin, _ := cmd.StdinPipe()
io.WriteString(stdin, "Hello, World!")
stdin.Close()
output, _ := cmd.CombinedOutput()
fmt.Println(string(output))

In this example, we use the StdinPipe function to get a pipe to the standard input stream of the command and write to it using io.WriteString.

Conclusion

The os/exec package in Go provides a powerful and flexible way to execute external commands and interact with them. It is a useful tool for building command-line interfaces and interacting with other system processes.

For more detailed information, you can refer to the official documentation.

Now you have a good understanding of how to use os/exec in Go to execute external commands, handle their input and output, and work with the standard streams.