      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
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    206
    207
    208
    209
    210
    211
    212
    213
    214
    215
    216
    217
    218
    219
    220
    221
    222
    223
    224
    225
    226
    227
    228
    229
    230
    231
    232
    233
    234
    235
    236
    237
    238
    239
    240
    241
    242
    243
    244
    245
    246
    247
    248
    249
    250
    251
    252
    253
    254
    255
    256
    257
    258
    259
    260
    261
    262
    263
    264
    265
    266
    267
    268
    269
    270
    271
    272
    273
    274
    275
    276
    277
    278
    279
    280
    281
    282
    283

    //! Rust friendly bindings to the various *nix system functions.
    //!
    //! Modules are structured according to the C header file that they would be
    //! defined in.
    #![crate_name = "nix"]
    #![cfg(unix)]
    #![allow(non_camel_case_types)]
    // latest bitflags triggers a rustc bug with cross-crate macro expansions causing dead_code
    // warnings even though the macro expands into something with allow(dead_code)
    #![allow(dead_code)]
    #![cfg_attr(test, deny(warnings))]
    #![recursion_limit = "500"]
    #![deny(unused)]
    #![deny(unstable_features)]
    #![deny(missing_copy_implementations)]
    #![deny(missing_debug_implementations)]

    // External crates
    #[macro_use]
    extern crate bitflags;
    #[macro_use]
    extern crate cfg_if;
    extern crate void;

    // Re-exported external crates
    pub extern crate libc;

    // Private internal modules
    #[macro_use] mod macros;

    // Public crates
    pub mod dir;
    pub mod errno;
    #[deny(missing_docs)]
    pub mod features;
    pub mod fcntl;
    #[deny(missing_docs)]
    #[cfg(any(target_os = "dragonfly",
              target_os = "freebsd",
              target_os = "ios",
              target_os = "linux",
              target_os = "macos",
              target_os = "netbsd",
              target_os = "openbsd"))]
    pub mod ifaddrs;
    #[cfg(any(target_os = "android",
              target_os = "linux"))]
    pub mod kmod;
    #[cfg(any(target_os = "android",
              target_os = "linux"))]
    pub mod mount;
    #[cfg(any(target_os = "dragonfly",
              target_os = "freebsd",
              target_os = "fushsia",
              target_os = "linux",
              target_os = "netbsd"))]
    pub mod mqueue;
    #[deny(missing_docs)]
    pub mod net;
    #[deny(missing_docs)]
    pub mod poll;
    #[deny(missing_docs)]
    pub mod pty;
    #[cfg(any(target_os = "android",
              target_os = "linux"))]
    pub mod sched;
    pub mod sys;
    // This can be implemented for other platforms as soon as libc
    // provides bindings for them.
    #[cfg(all(target_os = "linux",
              any(target_arch = "x86", target_arch = "x86_64")))]
    pub mod ucontext;
    pub mod unistd;

    /*
     *
     * ===== Result / Error =====
     *
     */

    use libc::{c_char, PATH_MAX};

    use std::{error, fmt, ptr, result};
    use std::ffi::{CStr, OsStr};
    use std::os::unix::ffi::OsStrExt;
    use std::path::{Path, PathBuf};

    use errno::Errno;

    /// Nix Result Type
    pub type Result<T> = result::Result<T, Error>;

    /// Nix Error Type
    ///
    /// The nix error type provides a common way of dealing with
    /// various system system/libc calls that might fail.  Each
    /// error has a corresponding errno (usually the one from the
    /// underlying OS) to which it can be mapped in addition to
    /// implementing other common traits.
    #[derive(Clone, Copy, Debug, PartialEq)]
    pub enum Error {
        Sys(Errno),
        InvalidPath,
        /// The operation involved a conversion to Rust's native String type, which failed because the
        /// string did not contain all valid UTF-8.
        InvalidUtf8,
        /// The operation is not supported by Nix, in this instance either use the libc bindings or
        /// consult the module documentation to see if there is a more appropriate interface available.
        UnsupportedOperation,
    }

    impl Error {
        /// Convert this `Error` to an [`Errno`](enum.Errno.html).
        ///
        /// # Example
        ///
        /// ```
        /// # use nix::Error;
        /// # use nix::errno::Errno;
        /// let e = Error::from(Errno::EPERM);
        /// assert_eq!(Some(Errno::EPERM), e.as_errno());
        /// ```
        pub fn as_errno(&self) -> Option<Errno> {
            if let &Error::Sys(ref e) = self {
                Some(*e)
            } else {
                None
            }
        }

        /// Create a nix Error from a given errno
        pub fn from_errno(errno: Errno) -> Error {
            Error::Sys(errno)
        }

        /// Get the current errno and convert it to a nix Error
        pub fn last() -> Error {
            Error::Sys(Errno::last())
        }

        /// Create a new invalid argument error (`EINVAL`)
        pub fn invalid_argument() -> Error {
            Error::Sys(Errno::EINVAL)
        }

    }

    impl From<Errno> for Error {
        fn from(errno: Errno) -> Error { Error::from_errno(errno) }
    }

    impl From<std::string::FromUtf8Error> for Error {
        fn from(_: std::string::FromUtf8Error) -> Error { Error::InvalidUtf8 }
    }

    impl error::Error for Error {
        fn description(&self) -> &str {
            match *self {
                Error::InvalidPath => "Invalid path",
                Error::InvalidUtf8 => "Invalid UTF-8 string",
                Error::UnsupportedOperation => "Unsupported Operation",
                Error::Sys(ref errno) => errno.desc(),
            }
        }
    }

    impl fmt::Display for Error {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            match *self {
                Error::InvalidPath => write!(f, "Invalid path"),
                Error::InvalidUtf8 => write!(f, "Invalid UTF-8 string"),
                Error::UnsupportedOperation => write!(f, "Unsupported Operation"),
                Error::Sys(errno) => write!(f, "{:?}: {}", errno, errno.desc()),
            }
        }
    }

    pub trait NixPath {
        fn len(&self) -> usize;

        fn with_nix_path<T, F>(&self, f: F) -> Result<T>
            where F: FnOnce(&CStr) -> T;
    }

    impl NixPath for str {
        fn len(&self) -> usize {
            NixPath::len(OsStr::new(self))
        }

        fn with_nix_path<T, F>(&self, f: F) -> Result<T>
            where F: FnOnce(&CStr) -> T {
                OsStr::new(self).with_nix_path(f)
            }
    }

    impl NixPath for OsStr {
        fn len(&self) -> usize {
            self.as_bytes().len()
        }

        fn with_nix_path<T, F>(&self, f: F) -> Result<T>
            where F: FnOnce(&CStr) -> T {
                self.as_bytes().with_nix_path(f)
            }
    }

    impl NixPath for CStr {
        fn len(&self) -> usize {
            self.to_bytes().len()
        }

        fn with_nix_path<T, F>(&self, f: F) -> Result<T>
                where F: FnOnce(&CStr) -> T {
            // Equivalence with the [u8] impl.
            if self.len() >= PATH_MAX as usize {
                return Err(Error::InvalidPath);
            }

            Ok(f(self))
        }
    }

    impl NixPath for [u8] {
        fn len(&self) -> usize {
            self.len()
        }

        fn with_nix_path<T, F>(&self, f: F) -> Result<T>
                where F: FnOnce(&CStr) -> T {
            let mut buf = [0u8; PATH_MAX as usize];

            if self.len() >= PATH_MAX as usize {
                return Err(Error::InvalidPath);
            }

            match self.iter().position(|b| *b == 0) {
                Some(_) => Err(Error::InvalidPath),
                None => {
                    unsafe {
                        // TODO: Replace with bytes::copy_memory. rust-lang/rust#24028
                        ptr::copy_nonoverlapping(self.as_ptr(), buf.as_mut_ptr(), self.len());
                        Ok(f(CStr::from_ptr(buf.as_ptr() as *const c_char)))
                    }

                }
            }
        }
    }

    impl NixPath for Path {
        fn len(&self) -> usize {
            NixPath::len(self.as_os_str())
        }

        fn with_nix_path<T, F>(&self, f: F) -> Result<T> where F: FnOnce(&CStr) -> T {
            self.as_os_str().with_nix_path(f)
        }
    }

    impl NixPath for PathBuf {
        fn len(&self) -> usize {
            NixPath::len(self.as_os_str())
        }

        fn with_nix_path<T, F>(&self, f: F) -> Result<T> where F: FnOnce(&CStr) -> T {
            self.as_os_str().with_nix_path(f)
        }
    }

    /// Treats `None` as an empty string.
    impl<'a, NP: ?Sized + NixPath>  NixPath for Option<&'a NP> {
        fn len(&self) -> usize {
            self.map_or(0, NixPath::len)
        }

        fn with_nix_path<T, F>(&self, f: F) -> Result<T> where F: FnOnce(&CStr) -> T {
            if let Some(nix_path) = *self {
                nix_path.with_nix_path(f)
            } else {
                unsafe { CStr::from_ptr("\0".as_ptr() as *const _).with_nix_path(f) }
            }
        }
    }

# 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`)