alias_unix.go

package utils

import (
	"bufio"
	"bytes"
	"errors"
	"fmt"
	"io"
	"os"
	"os/exec"
	"strings"
)

//AddAlias will add the alias for the package name specified
func (u *Utility) AddAliasUnix(name string, ed string) error {

	//get the home directory file path
	home, err := os.UserHomeDir()

	if err != nil {
		return err
	}

	//Get the shell PID
	ppid := fmt.Sprint(os.Getppid())

	//Create a list of commands to run and pipe together
	var cmds []exec.Cmd
	cmds = append(cmds, *exec.Command("ps", "-ef"))
	cmds = append(cmds, *exec.Command("awk", "{print $2 \" \" $8}"))
	cmds = append(cmds, *exec.Command("grep", ppid))
	cmds = append(cmds, *exec.Command("awk", "{print $2}"))

	var output []byte

	//Loop through the commands and run them
	for i, _ := range cmds {
		cmds[i].Stdin = bytes.NewReader(output)

		output, err = cmds[i].Output()

		if err != nil {
			return err
		}
	}

	var path string

	//Trim the output to get rid of any whitespace
	shell := strings.TrimSpace(string(output[:]))

	//Get the filepath for the correct shell rc file
	if shell == "bash" || shell == "-bash" {
		path = home + "/.bashrc"
	} else if shell == "zsh" || shell == "-zsh" {
		path = home + "/.zshrc"
	} else {
		return errors.New("Shell: " + shell + " is currently unsupported.")
	}

	//If run on linux lets modify the shell rc file to include the new aliases
	file, err := os.OpenFile(path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0755)

	if err != nil {
		return err
	}

	//Create the alias and write it to the file
	alias := "alias " + name + "=" + "\"" + ed + "/packageless run " + name + "\"" + "\n"

	_, err = file.WriteString(alias)

	if err != nil {
		return err
	}

	file.Close()

	return nil
}

//Remove Alias will remove the alias for the specified package name from the corresponding files
func (u *Utility) RemoveAliasUnix(name string, ed string) error {

	//get the home directory file path
	home, err := os.UserHomeDir()

	if err != nil {
		return err
	}

	//Get the shell PID
	ppid := fmt.Sprint(os.Getppid())

	//Create a list of commands to run and pipe them together
	var cmds []exec.Cmd
	cmds = append(cmds, *exec.Command("ps", "-ef"))
	cmds = append(cmds, *exec.Command("awk", "{print $2 \" \" $8}"))
	cmds = append(cmds, *exec.Command("grep", ppid))
	cmds = append(cmds, *exec.Command("awk", "{print $2}"))

	var output []byte

	//Loop through the commands and run them
	for i, _ := range cmds {
		cmds[i].Stdin = bytes.NewReader(output)

		output, err = cmds[i].Output()

		if err != nil {
			return err
		}
	}

	var path string

	//Trim the output whitespace
	shell := strings.TrimSpace(string(output[:]))

	//Get the filepath for the correct shell rc file
	if shell == "bash" || shell == "-bash" {
		path = home + "/.bashrc"
	} else if shell == "zsh" || shell == "-zsh" {
		path = home + "/.zshrc"
	} else {
		return errors.New("Shell: " + shell + " is currently unsupported.")
	}

	//Open the shell rc file
	file, err := os.OpenFile(path, os.O_RDWR, 0755)

	var newOut []string

	if err != nil {
		return err
	}

	reader := bufio.NewReader(file)

	//Read the file line by line
	for {
		line, err := reader.ReadString('\n')

		//Check for EOF
		if err != nil && err == io.EOF {
			break
		}

		if err != nil {
			return err
		}

		alias := "alias " + name + "=" + "\"" + ed + "/packageless run " + name + "\"" + "\n"

		//if the line is the alias for this package dont include it in the new file
		if line != alias {
			newOut = append(newOut, line)
		}
	}

	//Close the file
	file.Close()

	//Recreate the shell rc file
	newFile, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0755)

	if err != nil {
		return err
	}

	//Write the contents back to the shell rc file
	for _, line := range newOut {
		_, err = newFile.WriteString(line)

		if err != nil {
			return err
		}
	}

	//Close the file
	newFile.Close()

	return nil
}