Pacman update_all() works and gives errors properly.

src/main.rs

@@ -13,7 +13,6 @@
 
 use colored::{ColoredString, Colorize};
 
-mod install_check;
 mod pacman_api;
 mod shell_commands;
 
@@ -30,6 +29,7 @@ fn main() {
     notice_println("Running pacman update");
     if let Err(e) = pacman_api::update_all() {
         error_println(e.to_string());
+        return;
     }
 
     notice_println("Move onto something else");

src/pacman_api.rs

@@ -13,6 +13,7 @@
 
 use std::{error, fmt};
 use std::fmt::Formatter;
+use std::io::Read;
 use std::path::Path;
 
 use crate::shell_commands;
@@ -66,9 +67,26 @@ pub fn check() -> Result<(), PacmanError> {
 }
 
 pub fn update_all() -> Result<(), PacmanError> {
-    if let Err(e) = shell_commands::execute_in_sh("sudo pacman -Syu") {
+    let out = match shell_commands::execute_in_sh("pacman -Syu") {
+        Ok(out) => out,
+        Err(e) => return Err(PacmanError::Other(e.to_string())),
+    };
+
+    let mut child_stderr = match out.stderr {
+        Some(stderr) => stderr,
+        None => return Ok(()),
+    };
+
+    let mut stderr_out = String::new();
+    if let Err(e) = child_stderr.read_to_string(&mut stderr_out) {
         return Err(PacmanError::Other(e.to_string()));
     }
 
+    if stderr_out.is_empty() {
         Ok(())
+    } else if stderr_out == "error: you cannot perform this operation unless you are root.\n" {
+        Err(PacmanError::InsufficientPrivilege)
+    } else {
+        Err(PacmanError::Other(stderr_out))
+    }
 }

src/shell_commands.rs

@@ -13,21 +13,24 @@
 
 use std::ffi::OsStr;
 use std::io;
-use std::process::{Command, Output};
+use std::process::{Child, Command, Output, Stdio};
 
-pub fn execute_and_display<S: AsRef<OsStr>, I>(cmd: S, args: I) -> io::Result<()>
+pub fn execute_and_display<S: AsRef<OsStr>, I>(cmd: S, args: I) -> io::Result<Child>
 where
     I: IntoIterator,
     I::Item: AsRef<OsStr>,
 {
-    let mut child = Command::new(cmd).args(args).spawn()?;
+    let mut child = Command::new(cmd)
+        .args(args)
+        .stderr(Stdio::piped())
+        .spawn()?;
 
     child.wait()?;
 
-    Ok(())
+    Ok(child)
 }
 
-pub fn execute_in_sh(cmd: &'static str) -> io::Result<()> {
+pub fn execute_in_sh(cmd: &'static str) -> io::Result<Child> {
     execute_and_display("sh", ["-c", cmd])
 }