process.rs.html -- source
Description: Source to the Rust file `libstd/sys_common/process.rs`.
Keywords: rust, rustlang, rust-lang

      1
      2
      3
      4
      5
      6
      7
      8
      9
     10
     11
     12
     13
     14
     15
     16
     17
     18
     19
     20
     21
     22
     23
     24
     25
     26
     27
     28
     29
     30
     31
     32
     33
     34
     35
     36
     37
     38
     39
     40
     41
     42
     43
     44
     45
     46
     47
     48
     49
     50
     51
     52
     53
     54
     55
     56
     57
     58
     59
     60
     61
     62
     63
     64
     65
     66
     67
     68
     69
     70
     71
     72
     73
     74
     75
     76
     77
     78
     79
     80
     81
     82
     83
     84
     85
     86
     87
     88
     89
     90
     91
     92
     93
     94
     95
     96
     97
     98
     99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136

    // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
    // file at the top-level directory of this distribution and at
    // http://rust-lang.org/COPYRIGHT.
    //
    // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
    // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
    // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
    // option. This file may not be copied, modified, or distributed
    // except according to those terms.

    #![allow(dead_code)]
    #![unstable(feature = "process_internals", issue = "0")]

    use ffi::{OsStr, OsString};
    use env;
    use collections::BTreeMap;
    use borrow::Borrow;

    pub trait EnvKey:
        From<OsString> + Into<OsString> +
        Borrow<OsStr> + Borrow<Self> + AsRef<OsStr> +
        Ord + Clone {}

    // Implement a case-sensitive environment variable key
    #[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd)]
    pub struct DefaultEnvKey(OsString);

    impl From<OsString> for DefaultEnvKey {
        fn from(k: OsString) -> Self { DefaultEnvKey(k) }
    }

    impl From<DefaultEnvKey> for OsString {
        fn from(k: DefaultEnvKey) -> Self { k.0 }
    }

    impl Borrow<OsStr> for DefaultEnvKey {
        fn borrow(&self) -> &OsStr { &self.0 }
    }

    impl AsRef<OsStr> for DefaultEnvKey {
        fn as_ref(&self) -> &OsStr { &self.0 }
    }

    impl EnvKey for DefaultEnvKey {}

    // Stores a set of changes to an environment
    #[derive(Clone, Debug)]
    pub struct CommandEnv<K> {
        clear: bool,
        saw_path: bool,
        vars: BTreeMap<K, Option<OsString>>
    }

    impl<K: EnvKey> Default for CommandEnv<K> {
        fn default() -> Self {
            CommandEnv {
                clear: false,
                saw_path: false,
                vars: Default::default()
            }
        }
    }

    impl<K: EnvKey> CommandEnv<K> {
        // Capture the current environment with these changes applied
        pub fn capture(&self) -> BTreeMap<K, OsString> {
            let mut result = BTreeMap::<K, OsString>::new();
            if !self.clear {
                for (k, v) in env::vars_os() {
                    result.insert(k.into(), v);
                }
            }
            for (k, maybe_v) in &self.vars {
                if let &Some(ref v) = maybe_v {
                    result.insert(k.clone(), v.clone());
                } else {
                    result.remove(k);
                }
            }
            result
        }

        // Apply these changes directly to the current environment
        pub fn apply(&self) {
            if self.clear {
                for (k, _) in env::vars_os() {
                    env::remove_var(k);
                }
            }
            for (key, maybe_val) in self.vars.iter() {
                if let &Some(ref val) = maybe_val {
                    env::set_var(key, val);
                } else {
                    env::remove_var(key);
                }
            }
        }

        pub fn is_unchanged(&self) -> bool {
            !self.clear && self.vars.is_empty()
        }

        pub fn capture_if_changed(&self) -> Option<BTreeMap<K, OsString>> {
            if self.is_unchanged() {
                None
            } else {
                Some(self.capture())
            }
        }

        // The following functions build up changes
        pub fn set(&mut self, key: &OsStr, value: &OsStr) {
            self.maybe_saw_path(&key);
            self.vars.insert(key.to_owned().into(), Some(value.to_owned()));
        }
        pub fn remove(&mut self, key: &OsStr) {
            self.maybe_saw_path(&key);
            if self.clear {
                self.vars.remove(key);
            } else {
                self.vars.insert(key.to_owned().into(), None);
            }
        }
        pub fn clear(&mut self) {
            self.clear = true;
            self.vars.clear();
        }
        pub fn have_changed_path(&self) -> bool {
            self.saw_path || self.clear
        }
        fn maybe_saw_path(&mut self, key: &OsStr) {
            if !self.saw_path && key == "PATH" {
                self.saw_path = true;
            }
        }
    }

# Help

## Keyboard Shortcuts

`?`
  Show this help dialog
`S`
  Focus the search field
`↑`
  Move up in search results
`↓`
  Move down in search results
`↹`
  Switch tab
`⏎`
  Go to active search result
`+`
  Expand all sections
`-`
  Collapse all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)

Search multiple things at once by splitting your query with comma (e.g. `str,u8` or `String,struct:Vec,test`)