Make getenv return an Option instead of a Result

library/std/src/env.rs

@@ -244,7 +244,7 @@ pub fn var_os<K: AsRef<OsStr>>(key: K) -> Option<OsString> {
 }
 
 fn _var_os(key: &OsStr) -> Option<OsString> {
-    os_imp::getenv(key).ok()?
+    os_imp::getenv(key)
 }
 
 /// The error type for operations interacting with environment variables.

library/std/src/sys/hermit/os.rs

@@ -140,13 +140,8 @@ pub fn env() -> Env {
     }
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    unsafe {
-        match ENV.as_ref().unwrap().lock().unwrap().get_mut(k) {
-            Some(value) => Ok(Some(value.clone())),
-            None => Ok(None),
-        }
-    }
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    unsafe { ENV.as_ref().unwrap().lock().unwrap().get_mut(k).cloned() }
 }
 
 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {

library/std/src/sys/sgx/os.rs

@@ -106,8 +106,8 @@ pub fn env() -> Env {
     get_env_store().map(|env| clone_to_vec(&env.lock().unwrap())).unwrap_or_default().into_iter()
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    Ok(get_env_store().and_then(|s| s.lock().unwrap().get(k).cloned()))
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    get_env_store().and_then(|s| s.lock().unwrap().get(k).cloned())
 }
 
 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {

library/std/src/sys/unix/os.rs

@@ -532,19 +532,18 @@ pub fn env() -> Env {
     }
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
+pub fn getenv(k: &OsStr) -> Option<OsString> {
     // environment variables with a nul byte can't be set, so their value is
     // always None as well
-    let k = CString::new(k.as_bytes())?;
+    let k = CString::new(k.as_bytes()).ok()?;
     unsafe {
         let _guard = env_read_lock();
         let s = libc::getenv(k.as_ptr()) as *const libc::c_char;
-        let ret = if s.is_null() {
+        if s.is_null() {
             None
         } else {
             Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec()))
-        };
-        Ok(ret)
+        }
     }
 }
 

library/std/src/sys/unsupported/os.rs

@@ -76,8 +76,8 @@ pub fn env() -> Env {
     panic!("not supported on this platform")
 }
 
-pub fn getenv(_: &OsStr) -> io::Result<Option<OsString>> {
-    Ok(None)
+pub fn getenv(_: &OsStr) -> Option<OsString> {
+    None
 }
 
 pub fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {

library/std/src/sys/wasi/os.rs

@@ -175,17 +175,16 @@ pub fn env() -> Env {
     }
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    let k = CString::new(k.as_bytes())?;
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    let k = CString::new(k.as_bytes()).ok()?;
     unsafe {
         let _guard = env_lock();
         let s = libc::getenv(k.as_ptr()) as *const libc::c_char;
-        let ret = if s.is_null() {
+        if s.is_null() {
             None
         } else {
             Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec()))
-        };
-        Ok(ret)
+        }
     }
 }
 

library/std/src/sys/windows/os.rs

@@ -253,22 +253,13 @@ pub fn chdir(p: &path::Path) -> io::Result<()> {
     cvt(unsafe { c::SetCurrentDirectoryW(p.as_ptr()) }).map(drop)
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    let k = to_u16s(k)?;
-    let res = super::fill_utf16_buf(
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    let k = to_u16s(k).ok()?;
+    super::fill_utf16_buf(
         |buf, sz| unsafe { c::GetEnvironmentVariableW(k.as_ptr(), buf, sz) },
         |buf| OsStringExt::from_wide(buf),
-    );
-    match res {
-        Ok(value) => Ok(Some(value)),
-        Err(e) => {
-            if e.raw_os_error() == Some(c::ERROR_ENVVAR_NOT_FOUND as i32) {
-                Ok(None)
-            } else {
-                Err(e)
-            }
-        }
-    }
+    )
+    .ok()
 }
 
 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {