2 #![unstable(feature = "process_internals", issue = "none")]
4 use crate::collections::BTreeMap;
6 use crate::ffi::{OsStr, OsString};
7 use crate::sys::process::EnvKey;
9 // Stores a set of changes to an environment
10 #[derive(Clone, Debug)]
11 pub struct CommandEnv {
14 vars: BTreeMap<EnvKey, Option<OsString>>,
17 impl Default for CommandEnv {
18 fn default() -> Self {
19 CommandEnv { clear: false, saw_path: false, vars: Default::default() }
24 // Capture the current environment with these changes applied
25 pub fn capture(&self) -> BTreeMap<EnvKey, OsString> {
26 let mut result = BTreeMap::<EnvKey, OsString>::new();
28 for (k, v) in env::vars_os() {
29 result.insert(k.into(), v);
32 for (k, maybe_v) in &self.vars {
33 if let &Some(ref v) = maybe_v {
34 result.insert(k.clone(), v.clone());
42 pub fn is_unchanged(&self) -> bool {
43 !self.clear && self.vars.is_empty()
46 pub fn capture_if_changed(&self) -> Option<BTreeMap<EnvKey, OsString>> {
47 if self.is_unchanged() { None } else { Some(self.capture()) }
50 // The following functions build up changes
51 pub fn set(&mut self, key: &OsStr, value: &OsStr) {
52 let key = EnvKey::from(key);
53 self.maybe_saw_path(&key);
54 self.vars.insert(key, Some(value.to_owned()));
57 pub fn remove(&mut self, key: &OsStr) {
58 let key = EnvKey::from(key);
59 self.maybe_saw_path(&key);
61 self.vars.remove(&key);
63 self.vars.insert(key, None);
67 pub fn clear(&mut self) {
72 pub fn have_changed_path(&self) -> bool {
73 self.saw_path || self.clear
76 fn maybe_saw_path(&mut self, key: &EnvKey) {
77 if !self.saw_path && key == "PATH" {
82 pub fn iter(&self) -> CommandEnvs<'_> {
83 let iter = self.vars.iter();
88 /// An iterator over the command environment variables.
90 /// This struct is created by
91 /// [`Command::get_envs`][crate::process::Command::get_envs]. See its
92 /// documentation for more.
93 #[must_use = "iterators are lazy and do nothing unless consumed"]
94 #[stable(feature = "command_access", since = "1.57.0")]
96 pub struct CommandEnvs<'a> {
97 iter: crate::collections::btree_map::Iter<'a, EnvKey, Option<OsString>>,
100 #[stable(feature = "command_access", since = "1.57.0")]
101 impl<'a> Iterator for CommandEnvs<'a> {
102 type Item = (&'a OsStr, Option<&'a OsStr>);
103 fn next(&mut self) -> Option<Self::Item> {
104 self.iter.next().map(|(key, value)| (key.as_ref(), value.as_deref()))
106 fn size_hint(&self) -> (usize, Option<usize>) {
107 self.iter.size_hint()
111 #[stable(feature = "command_access", since = "1.57.0")]
112 impl<'a> ExactSizeIterator for CommandEnvs<'a> {
113 fn len(&self) -> usize {
116 fn is_empty(&self) -> bool {