1use crate::ffi::{OsStr, OsString};
2use crate::os::windows::prelude::*;
3use crate::sys::pal::{c, cvt, fill_utf16_buf, to_u16s};
4use crate::{fmt, io, ptr, slice};
5
6pub struct Env {
7 base: *mut c::WCHAR,
8 iter: EnvIterator,
9}
10
11pub struct EnvStrDebug<'a> {
13 iter: &'a EnvIterator,
14}
15
16impl fmt::Debug for EnvStrDebug<'_> {
17 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
18 let Self { iter } = self;
19 let iter: EnvIterator = (*iter).clone();
20 let mut list = f.debug_list();
21 for (a, b) in iter {
22 list.entry(&(a.to_str().unwrap(), b.to_str().unwrap()));
23 }
24 list.finish()
25 }
26}
27
28impl Env {
29 pub fn str_debug(&self) -> impl fmt::Debug + '_ {
30 let Self { base: _, iter } = self;
31 EnvStrDebug { iter }
32 }
33}
34
35impl fmt::Debug for Env {
36 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
37 let Self { base: _, iter } = self;
38 f.debug_list().entries(iter.clone()).finish()
39 }
40}
41
42impl Iterator for Env {
43 type Item = (OsString, OsString);
44
45 fn next(&mut self) -> Option<(OsString, OsString)> {
46 let Self { base: _, iter } = self;
47 iter.next()
48 }
49}
50
51#[derive(Clone)]
52struct EnvIterator(*mut c::WCHAR);
53
54impl Iterator for EnvIterator {
55 type Item = (OsString, OsString);
56
57 fn next(&mut self) -> Option<(OsString, OsString)> {
58 let Self(cur) = self;
59 loop {
60 unsafe {
61 if **cur == 0 {
62 return None;
63 }
64 let p = *cur as *const u16;
65 let mut len = 0;
66 while *p.add(len) != 0 {
67 len += 1;
68 }
69 let s = slice::from_raw_parts(p, len);
70 *cur = cur.add(len + 1);
71
72 let pos = match s[1..].iter().position(|&u| u == b'=' as u16).map(|p| p + 1) {
78 Some(p) => p,
79 None => continue,
80 };
81 return Some((
82 OsStringExt::from_wide(&s[..pos]),
83 OsStringExt::from_wide(&s[pos + 1..]),
84 ));
85 }
86 }
87 }
88}
89
90impl Drop for Env {
91 fn drop(&mut self) {
92 unsafe {
93 c::FreeEnvironmentStringsW(self.base);
94 }
95 }
96}
97
98pub fn env() -> Env {
99 unsafe {
100 let ch = c::GetEnvironmentStringsW();
101 if ch.is_null() {
102 panic!("failure getting env string from OS: {}", io::Error::last_os_error());
103 }
104 Env { base: ch, iter: EnvIterator(ch) }
105 }
106}
107
108pub fn getenv(k: &OsStr) -> Option<OsString> {
109 let k = to_u16s(k).ok()?;
110 fill_utf16_buf(
111 |buf, sz| unsafe { c::GetEnvironmentVariableW(k.as_ptr(), buf, sz) },
112 OsStringExt::from_wide,
113 )
114 .ok()
115}
116
117pub unsafe fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
118 unsafe {
120 let k = to_u16s(k)?;
121 let v = to_u16s(v)?;
122
123 cvt(c::SetEnvironmentVariableW(k.as_ptr(), v.as_ptr())).map(drop)
124 }
125}
126
127pub unsafe fn unsetenv(n: &OsStr) -> io::Result<()> {
128 unsafe {
130 let v = to_u16s(n)?;
131 cvt(c::SetEnvironmentVariableW(v.as_ptr(), ptr::null())).map(drop)
132 }
133}