gethostname

https://docs.rs/gethostname/1.1.0
Admin
A cross-platform Rust crate that retrieves the system hostname with support for Unix and Windows...
Tokens:1,995
Snippets:30
Trust Score:9.1
Update:5 months ago
Show doc for...
Tokens:
Raw
### Get Hostname Example

Source: https://docs.rs/gethostname/1.1.0/src/gethostname/lib.rs.html

Demonstrates how to use the `gethostname` function to retrieve and print the system's hostname. This is the primary usage example for the crate.

```rust
use gethostname::gethostname;

println!("Hostname: {:?}", gethostname());

```

--------------------------------

### Test: Compare with System Hostname

Source: https://docs.rs/gethostname/1.1.0/src/gethostname/lib.rs.html

This test verifies that the `gethostname` function returns the same value as the system's `hostname` command (or `uname -n` on non-Windows systems). It executes an external command to get the system's hostname.

```rust
let mut command = if cfg!(windows) {
    Command::new("hostname")
} else {
    let mut uname = Command::new("uname");
    uname.arg("-n");
    uname
};
let output = command.output().expect("failed to get hostname");

```

--------------------------------

### gethostname()

Source: https://docs.rs/gethostname/1.1.0/gethostname/fn.gethostname.html

Retrieves the standard host name for the current machine. On Unix, it uses `rustix::system::uname` to get the node name. On Windows, it calls `GetComputerNameExW` with `ComputerNamePhysicalDnsHostname`. Be aware of a potential race condition on Windows.

```APIDOC
## Function gethostname

### Description
Get the standard host name for the current machine.

On Unix call `rustix::system::uname` to obtain the node name, see `rustix::system::Uname::nodename`.
On Windows return the DNS host name of the local computer, as returned by GetComputerNameExW with `ComputerNamePhysicalDnsHostname` as `NameType`. We call this function twice to obtain the appropriate buffer size; there is a race condition window between these two calls where a change to the node name would result in a wrong buffer size which could cause this function to panic.

Note that this host name does not have a well-defined meaning in terms of network name resolution. Specifically, it’s not guaranteed that the returned name can be resolved in any particular way, e.g. DNS.

### Signature
```rust
pub fn gethostname() -> OsString
```
```

--------------------------------

### Get Hostname in Rust

Source: https://docs.rs/gethostname/1.1.0/index.html

Use the `gethostname` function from the `gethostname` crate to retrieve the hostname. This function is available for all supported platforms.

```rust
use gethostname::gethostname;

println!("Hostname: {:?}", gethostname());
```

--------------------------------

### Test Hostname Retrieval and Comparison

Source: https://docs.rs/gethostname/1.1.0/src/gethostname/lib.rs.html

This test verifies that the gethostname function correctly retrieves the system's hostname and compares it against the output of an external command. It handles potential errors during command execution and ensures the retrieved hostname is not empty.

```rust
if output.status.success() {
            let hostname = String::from_utf8_lossy(&output.stdout);
            assert!(
                !hostname.is_empty(),
                "Failed to get hostname: hostname empty?"
            );
            // Convert both sides to lowercase; hostnames are case-insensitive
            // anyway.
            assert_eq!(
                super::gethostname().into_string().unwrap().to_lowercase(),
                hostname.trim_end().to_lowercase()
            );
        } else {
            panic!(
                "Failed to get hostname! {}",
                String::from_utf8_lossy(&output.stderr)
            );
        }
```

--------------------------------

### gethostname() function

Source: https://docs.rs/gethostname/1.1.0/index.html

Retrieves the standard host name for the current machine.

```APIDOC
## Function: gethostname

### Description
Get the standard host name for the current machine.

### Usage
```rust
use gethostname::gethostname;

println!("Hostname: {:?}", gethostname());
```

### Return Value
Returns the hostname as a `String`.
```

--------------------------------

### gethostname()

Source: https://docs.rs/gethostname/1.1.0/gethostname

Retrieves the standard host name for the current machine. This function is available for all platforms supported by the crate.

```APIDOC
## Function: gethostname

### Description
Get the standard host name for the current machine.

### Usage
```rust
use gethostname::gethostname;

println!("Hostname: {:?}", gethostname());
```

### Return Value
Returns the hostname as a `Cow<'_, str>`.
```

--------------------------------

### gethostname() Function

Source: https://docs.rs/gethostname/1.1.0/gethostname/index.html

Retrieves the standard host name for the current machine. This function is available for all supported platforms.

```APIDOC
## Function: gethostname

### Description
Get the standard host name for the current machine.

### Usage
```rust
use gethostname::gethostname;

println!("Hostname: {:?}", gethostname());
```

### Returns
The hostname of the current machine as a `Cow<'_, str>`.
```

--------------------------------

### Windows Hostname Retrieval

Source: https://docs.rs/gethostname/1.1.0/src/gethostname/lib.rs.html

On Windows, this function retrieves the DNS hostname using `GetComputerNameExW` with `ComputerNamePhysicalDnsHostname`. It handles buffer sizing and potential race conditions.

```rust
pub const COMPUTER_NAME_PHYSICAL_DNS_HOSTNAME: i32 = 5;
::windows_link::link!("kernel32.dll" "system" fn GetComputerNameExW(nametype: i32, lpbuffer: *mut u16, nsize: *mut u32) -> i32);

let mut buffer_size: u32 = 0;

unsafe {
    GetComputerNameExW(
        COMPUTER_NAME_PHYSICAL_DNS_HOSTNAME,
        std::ptr::null_mut(),
        &mut buffer_size,
    )
};
assert!(0 < buffer_size, "GetComputerNameExW did not provide buffer size");

let mut buffer = vec![0_u16; buffer_size as usize];
unsafe {
    if GetComputerNameExW(
        COMPUTER_NAME_PHYSICAL_DNS_HOSTNAME,
        buffer.as_mut_ptr(),
        &mut buffer_size,
    ) == 0 {
        panic!("GetComputerNameExW failed to read hostname.");
    }
}
assert!(buffer_size as usize == buffer.len() - 1, "GetComputerNameExW changed the buffer size unexpectedly");

let end = buffer.iter().position(|&b| b == 0).unwrap_or(buffer.len());
OsString::from_wide(&buffer[0..end])

```

--------------------------------

### Unix Hostname Retrieval

Source: https://docs.rs/gethostname/1.1.0/src/gethostname/lib.rs.html

On Unix-like systems, this function retrieves the hostname by calling `rustix::system::uname` and extracting the nodename. Ensure `rustix` is available for Unix targets.

```rust
use std::os::unix::ffi::OsStringExt;
OsString::from_vec(rustix::system::uname().nodename().to_bytes().to_vec())

```
Tokens:
Raw