Fallible for username(), realname() and _os varaints

src/fake.rs

@@ -13,13 +13,13 @@ pub(crate) fn lang() -> impl Iterator<Item = String> {
 }
 
 #[inline(always)]
-pub(crate) fn username_os() -> OsString {
-    username().into()
+pub(crate) fn username_os() -> Result<OsString> {
+    Ok(username()?.into())
 }
 
 #[inline(always)]
-pub(crate) fn realname_os() -> OsString {
-    realname().into()
+pub(crate) fn realname_os() -> Result<OsString> {
+    Ok(realname()?.into())
 }
 
 #[inline(always)]
@@ -33,12 +33,12 @@ pub(crate) fn distro_os() -> Option<OsString> {
 }
 
 #[inline(always)]
-pub(crate) fn username() -> String {
-    "anonymous".to_string()
+pub(crate) fn username() -> Result<String> {
+    Ok("anonymous".to_string())
 }
 
 #[inline(always)]
-pub(crate) fn realname() -> String {
+pub(crate) fn realname() -> Result<String> {
     "Anonymous".to_string()
 }
 

src/fallible.rs

@@ -0,0 +1,39 @@
+//! Fallible versions of the whoami APIs.
+//!
+//! Some of the functions in the root module will return "Unknown" on error.
+//! This might not be desirable in some situations.  The functions in this
+//! module all return a [`Result`].
+
+use std::ffi::OsString;
+
+use crate::{platform, Result};
+
+/// Get the user's username.
+///
+/// On unix-systems this differs from [`realname()`] most notably in that spaces
+/// are not allowed.
+#[inline(always)]
+pub fn username() -> Result<String> {
+    platform::username()
+}
+
+/// Get the user's username.
+///
+/// On unix-systems this differs from [`realname()`] most notably in that spaces
+/// are not allowed.
+#[inline(always)]
+pub fn username_os() -> Result<OsString> {
+    platform::username_os()
+}
+
+/// Get the user's real (full) name.
+#[inline(always)]
+pub fn realname() -> Result<String> {
+    platform::realname()
+}
+
+/// Get the user's real (full) name.
+#[inline(always)]
+pub fn realname_os() -> Result<OsString> {
+    platform::realname_os()
+}

src/lib.rs

@@ -70,6 +70,10 @@
     html_favicon_url = "https://raw.githubusercontent.com/ardaku/whoami/stable/res/icon.svg"
 )]
 
+const DEFAULT_USERNAME: &str = "Unknown";
+
+pub mod fallible;
+
 #[allow(unsafe_code)]
 // Unix
 #[cfg_attr(
@@ -395,7 +399,7 @@ pub fn arch() -> Arch {
 /// are not allowed.
 #[inline(always)]
 pub fn username() -> String {
-    platform::username()
+    fallible::username().unwrap_or_else(|_| DEFAULT_USERNAME.to_owned())
 }
 
 /// Get the user's username.
@@ -404,19 +408,21 @@ pub fn username() -> String {
 /// are not allowed.
 #[inline(always)]
 pub fn username_os() -> OsString {
-    platform::username_os()
+    fallible::username_os()
+        .unwrap_or_else(|_| DEFAULT_USERNAME.to_owned().into())
 }
 
 /// Get the user's real (full) name.
 #[inline(always)]
 pub fn realname() -> String {
-    platform::realname()
+    fallible::realname().unwrap_or_else(|_| DEFAULT_USERNAME.to_owned())
 }
 
 /// Get the user's real (full) name.
 #[inline(always)]
 pub fn realname_os() -> OsString {
-    platform::realname_os()
+    fallible::realname_os()
+        .unwrap_or_else(|_| DEFAULT_USERNAME.to_owned().into())
 }
 
 /// Get the device name (also known as "Pretty Name").

src/unix.rs

@@ -1,6 +1,7 @@
 use std::{
     borrow::Cow,
     ffi::{c_void, CStr, OsString},
+    io::{Error, ErrorKind},
     mem,
     os::{
         raw::{c_char, c_int},
@@ -16,7 +17,7 @@ use std::{
     ptr::null_mut,
 };
 
-use crate::{Arch, DesktopEnv, Platform};
+use crate::{Arch, DesktopEnv, Platform, Result};
 
 #[repr(C)]
 struct PassWd {
@@ -192,7 +193,7 @@ fn os_from_cfstring(string: *mut c_void) -> OsString {
 // This function must allocate, because a slice or Cow<OsStr> would still
 // reference `passwd` which is dropped when this function returns.
 #[inline(always)]
-fn getpwuid(real: bool) -> OsString {
+fn getpwuid(real: bool) -> Result<OsString> {
     const BUF_SIZE: usize = 16_384; // size from the man page
     let mut buffer = mem::MaybeUninit::<[u8; BUF_SIZE]>::uninit();
     let mut passwd = mem::MaybeUninit::<PassWd>::uninit();
@@ -209,20 +210,20 @@ fn getpwuid(real: bool) -> OsString {
         );
 
         if ret != 0 {
-            return "Unknown".to_string().into();
+            return Err(Error::last_os_error());
         }
 
         let _passwd = _passwd.assume_init();
 
         if _passwd.is_null() {
-            return "Unknown".to_string().into();
+            return Err(Error::new(ErrorKind::NotFound, "Missing record"));
         }
 
         passwd.assume_init()
     };
 
     // Extract names.
-    if real {
+    Ok(if real {
         let string = os_from_cstring_gecos(passwd.pw_gecos);
         let result = if let Some(string) = string {
             Ok(string)
@@ -232,14 +233,14 @@ fn getpwuid(real: bool) -> OsString {
         fancy_fallback_os(result)
     } else {
         os_from_cstring(passwd.pw_name)
-    }
+    })
 }
 
-pub(crate) fn username() -> String {
-    string_from_os(username_os())
+pub(crate) fn username() -> Result<String> {
+    Ok(string_from_os(username_os()?))
 }
 
-pub(crate) fn username_os() -> OsString {
+pub(crate) fn username_os() -> Result<OsString> {
     getpwuid(false)
 }
 
@@ -285,11 +286,11 @@ fn fancy_fallback_os(result: Result<OsString, OsString>) -> OsString {
     }
 }
 
-pub(crate) fn realname() -> String {
-    string_from_os(realname_os())
+pub(crate) fn realname() -> Result<String> {
+    Ok(string_from_os(realname_os()?))
 }
 
-pub(crate) fn realname_os() -> OsString {
+pub(crate) fn realname_os() -> Result<OsString> {
     getpwuid(true)
 }
 

src/web.rs

@@ -53,13 +53,13 @@ pub(crate) fn lang() -> impl Iterator<Item = String> {
 }
 
 #[inline(always)]
-pub(crate) fn username_os() -> OsString {
-    username().into()
+pub(crate) fn username_os() -> Result<OsString> {
+    Ok(username()?.into())
 }
 
 #[inline(always)]
-pub(crate) fn realname_os() -> OsString {
-    realname().into()
+pub(crate) fn realname_os() -> Result<OsString> {
+    Ok(realname()?.into())
 }
 
 #[inline(always)]
@@ -73,13 +73,13 @@ pub(crate) fn distro_os() -> Option<OsString> {
 }
 
 #[inline(always)]
-pub(crate) fn username() -> String {
-    "anonymous".to_string()
+pub(crate) fn username() -> Result<String> {
+    Ok("anonymous".to_string())
 }
 
 #[inline(always)]
-pub(crate) fn realname() -> String {
-    "Anonymous".to_string()
+pub(crate) fn realname() -> Result<String> {
+    Ok("Anonymous".to_string())
 }
 
 pub(crate) fn devicename() -> String {

src/windows.rs

@@ -1,6 +1,7 @@
 use std::{
     convert::TryInto,
     ffi::OsString,
+    io::Error,
     mem::MaybeUninit,
     os::{
         raw::{c_char, c_int, c_uchar, c_ulong, c_ushort, c_void},
@@ -9,7 +10,7 @@ use std::{
     ptr,
 };
 
-use crate::{Arch, DesktopEnv, Platform};
+use crate::{Arch, DesktopEnv, Platform, Result};
 
 #[repr(C)]
 struct OsVersionInfoEx {
@@ -109,11 +110,11 @@ fn string_from_os(string: OsString) -> String {
     }
 }
 
-pub(crate) fn username() -> String {
-    string_from_os(username_os())
+pub(crate) fn username() -> Result<String> {
+    Ok(string_from_os(username_os()?))
 }
 
-pub(crate) fn username_os() -> OsString {
+pub(crate) fn username_os() -> Result<OsString> {
     // Step 1. Retreive the entire length of the username
     let mut size = 0;
     let success = unsafe {
@@ -130,7 +131,7 @@ pub(crate) fn username_os() -> OsString {
     let fail =
         unsafe { GetUserNameW(name.as_mut_ptr().cast(), &mut size) == 0 };
     if fail {
-        return "unknown".to_string().into();
+        return Err(Error::last_os_error());
     }
     debug_assert_eq!(orig_size, size);
     unsafe {
@@ -140,16 +141,16 @@ pub(crate) fn username_os() -> OsString {
     debug_assert_eq!(terminator, Some(0u16));
 
     // Step 3. Convert to Rust String
-    OsString::from_wide(&name)
+    Ok(OsString::from_wide(&name))
 }
 
 #[inline(always)]
-pub(crate) fn realname() -> String {
-    string_from_os(realname_os())
+pub(crate) fn realname() -> Result<String> {
+    Ok(string_from_os(realname_os()?))
 }
 
 #[inline(always)]
-pub(crate) fn realname_os() -> OsString {
+pub(crate) fn realname_os() -> Result<OsString> {
     // Step 1. Retrieve the entire length of the username
     let mut buf_size = 0;
     let success = unsafe {
@@ -180,15 +181,15 @@ pub(crate) fn realname_os() -> OsString {
         ) == 0
     };
     if fail {
-        return "Unknown".to_string().into();
+        return Err(Error::last_os_error());
     }
     debug_assert_eq!(buf_size, name_len + 1);
     unsafe {
         name.set_len(name_len.try_into().unwrap_or(std::usize::MAX));
     }
 
     // Step 3. Convert to Rust String
-    OsString::from_wide(&name)
+    Ok(OsString::from_wide(&name))
 }
 
 #[inline(always)]