Function getenvW [src]

Windows-only. Get an environment variable with a null-terminated, WTF-16 encoded name. This function performs a Unicode-aware case-insensitive lookup using RtlEqualUnicodeString. See also: std.posix.getenv getEnvMap getEnvVarOwned hasEnvVarConstant hasEnvVar

Prototype

pub fn getenvW(key: [*:0]const u16) ?[:0]const u16

Parameters

key: [*:0]const u16

Source

  pub fn getenvW(key: [*:0]const u16) ?[:0]const u16 {
    if (native_os != .windows) {
        @compileError("Windows-only");
    }
    const key_slice = mem.sliceTo(key, 0);
    const ptr = windows.peb().ProcessParameters.Environment;
    var i: usize = 0;
    while (ptr[i] != 0) {
        const key_start = i;

        // There are some special environment variables that start with =,
        // so we need a special case to not treat = as a key/value separator
        // if it's the first character.
        // https://devblogs.microsoft.com/oldnewthing/20100506-00/?p=14133
        if (ptr[key_start] == '=') i += 1;

        while (ptr[i] != 0 and ptr[i] != '=') : (i += 1) {}
        const this_key = ptr[key_start..i];

        if (ptr[i] == '=') i += 1;

        const value_start = i;
        while (ptr[i] != 0) : (i += 1) {}
        const this_value = ptr[value_start..i :0];

        if (windows.eqlIgnoreCaseWTF16(key_slice, this_key)) {
            return this_value;
        }

        i += 1; // skip over null byte
    }
    return null;
}  