do it better

paths/TODO

@@ -1,8 +0,0 @@
-https://golangcode.com/check-if-a-file-exists/
-
-E.G.
-func fileExists(filename string) bool {
-    info, err := os.Stat(filename)
-    if os.IsNotExist(err) {
-        return false
-    }

paths/func.go

@@ -19,8 +19,10 @@
 package paths
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/user"
 	"path/filepath"
@@ -31,37 +33,75 @@ import (
 
 var err error
 
-func ExpandHome(path *string) error {
+func ExpandHome(path *string) (err error) {
 	// Props to this guy.
 	// https://stackoverflow.com/a/43578461/733214
 	if len(*path) == 0 {
 		return errors.New("empty path")
 	} else if (*path)[0] != '~' {
-		return nil
+		return
 	}
 	// E(ffective)UID (e.g. chown'd user for SUID)
 	/*
-	uid := strconv.Itoa(syscall.Geteuid())
-	usr, err := user.LookupId(euid)
+		uid := strconv.Itoa(syscall.Geteuid())
+		usr, err := user.LookupId(euid)
 	*/
 	// R(real)UID (invoking user)
 	usr, err := user.Current()
 	if err != nil {
-		return err
+		return
 	}
 	*path = filepath.Join(usr.HomeDir, (*path)[1:])
-	return nil
+	return
 }
 
-func GetPathEnv() ([]string, error) {
-	paths := []string{}
+func GetPathEnv() (s []string, err error) {
+	s = make([]string, 0)
 	for _, p := range strings.Split(os.Getenv("PATH"), ":") {
 		if err = RealPath(&p); err != nil {
-			return nil, err
+			return
 		}
-		paths = append(paths, p)
+		s = append(s, p)
 	}
-	return paths, nil
+
+	return
+}
+
+func GetEnvPid(pid uint32) (env map[string]string, err error) {
+
+	var envBytes []byte
+	var envArr [][]byte
+	var procPath string
+	var exists bool
+
+	env = make(map[string]string)
+
+	procPath = fmt.Sprintf("/proc/%v/environ", pid)
+
+	if exists, err = RealPathExists(&procPath); err != nil {
+		return
+	}
+	if !exists {
+		err = errors.New(fmt.Sprintf("information for pid %v does not exist", pid))
+	}
+	if envBytes, err = ioutil.ReadFile(procPath); err != nil {
+		return
+	}
+
+	envArr = bytes.Split(envBytes, []byte{0x0})
+	for _, b := range envArr {
+		// s := strings.TrimSpace(string(b))
+		s := string(b)
+		e := strings.SplitN(s, "=", 2)
+		for _, i := range e {
+			if len(i) != 2 {
+				continue
+			}
+			env[string(i[0])] = string(i[1])
+		}
+	}
+
+	return
 }
 
 func MakeDirIfNotExist(path *string) error {
@@ -97,31 +137,38 @@ func RealPath(path *string) error {
 	return nil
 }
 
-func RealPathExists(path *string) (bool, error) {
-	// I know it's hacky, but we use the bool as a sort of proto-state-machine thing.
-	// If err != nil and bool is true, the error occurred during path absolution.
-	// If err != nil and bool is false, the path does not exist.
-	err := RealPath(path)
-	if err != nil {
-		return true, err
+func RealPathExists(path *string) (exists bool, err error) {
+	if err = RealPath(path); err != nil {
+		return
 	}
 	if _, err := os.Stat(*path); err != nil {
-		return false, err
+		if os.IsNotExist(err) {
+			exists = false
+			err = nil
+		} else {
+			return
+		}
+	} else {
+		exists = true
 	}
-	return true, nil
+
+	return
 }
 
-func RealPathExistsStat(path *string) (bool, os.FileInfo, error) {
-	// Same deal as RealPathExists.
-	// If err != nil and bool is true, the error occurred during path absolution.
-	// If err != nil and bool is false, the path does not exist.
-	err := RealPath(path)
-	if err != nil {
-		return true, nil, err
+func RealPathExistsStat(path *string) (exists bool, stat os.FileInfo, err error) {
+	if err = RealPath(path); err != nil {
+		return
 	}
-	stat, err := os.Stat(*path)
-	if err != nil {
-		return false, nil, err
+	if stat, err = os.Stat(*path); err != nil {
+		if os.IsNotExist(err) {
+			exists = false
+			err = nil
+		} else {
+			return
+		}
+	} else {
+		exists = true
 	}
-	return true, stat, nil
+
+	return
 }