Executing an Embedded Bash Script in Go With Interactive Input

This article will delve further into the code and explain how to enable interactive input when executing the embedded Bash script. We’ll walk through the code and understand how to connect the Go program’s standard input to the command’s standard input, allowing interaction with the Bash script.

1. Overview of the Code

The provided code is a Go program that executes an embedded Bash script. It imports necessary packages such as fmt, log, os, and os/exec to handle command execution, input/output, and error handling.

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package main

import (
 _ "bufio"
 _ "embed"
 "fmt"
 "log"
 "os"
 "os/exec"
 "strings"
)

//go:embed bash.sh
var scriptContent string

func main() {
 args := os.Args[1:] // Get the command-line arguments excluding the program name

 // Start a new shell session with the embedded script
 cmd := exec.Command("/bin/bash", "-c", scriptContent)

 cmd.Stdout = os.Stdout
 cmd.Stderr = os.Stderr

 // Connect os.Stdin to the command's stdin
 cmd.Stdin = os.Stdin

 // Pass the command-line arguments as environment variables to the command
 cmd.Env = append(os.Environ(), fmt.Sprintf("ARGS=%s", strings.Join(args, " ")))

 // Execute the command
 err := cmd.Run()
 if err != nil {
  log.Fatalf("Failed to execute bash script: %v", err)
 }

 fmt.Println("Bash script executed successfully.")
}

2. Embedding the Bash Script

The code leverages Go’s embed package to embed the content of the bash.sh file into a string variable named scriptContent. This ensures that the Bash script is included within the Go program during the build process.

3. Command Execution and Input/Output Handling

The program creates a new command using exec.Command, specifying /bin/bash as the shell and scriptContent as the script to execute. It configures the standard output and error of the command to use the corresponding streams of the Go program (cmd.Stdout = os.Stdout and cmd.Stderr = os.Stderr). Additionally, the program connects the Go program’s standard input to the command’s standard input (cmd.Stdin = os.Stdin).

4. Enabling Interactive Input

To enable interactive input on the embedded Bash script, the program establishes a connection between the Go program’s standard input and the command’s standard input. This allows users to provide input interactively during script execution. By setting cmd.Stdin = os.Stdin, any input entered in the Go program’s command line will be passed to the embedded Bash script.

5. Error Handling

If there is an error during command execution, the program logs a fatal error message using log.Fatalf and terminates. This ensures that any issues encountered during script execution are clearly reported.

6. Conclusion

In this article, we explored how to execute an embedded Bash script within a Go program and enable interactive input. By connecting the Go program’s standard input to the command’s standard input, we can interactively provide input during script execution. This capability enhances the flexibility and usefulness of executing embedded Bash scripts in Go applications.