Function getEnvMap [src]

Returns a snapshot of the environment variables of the current process. Any modifications to the resulting EnvMap will not be reflected in the environment, and likewise, any future modifications to the environment will not be reflected in the EnvMap. Caller owns resulting EnvMap and should call its deinit fn when done.

Prototype

pub fn getEnvMap(allocator: Allocator) GetEnvMapError!EnvMap

Parameters

allocator: Allocator

Possible Errors

OutOfMemory

Unexpected

WASI-only. environ_sizes_get or environ_get failed for an unexpected reason.

Example

 test getEnvMap {
    var env = try getEnvMap(testing.allocator);
    defer env.deinit();
}

Source

  pub fn getEnvMap(allocator: Allocator) GetEnvMapError!EnvMap {
    var result = EnvMap.init(allocator);
    errdefer result.deinit();

    if (native_os == .windows) {
        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 key_w = ptr[key_start..i];
            const key = try unicode.wtf16LeToWtf8Alloc(allocator, key_w);
            errdefer allocator.free(key);

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

            const value_start = i;
            while (ptr[i] != 0) : (i += 1) {}
            const value_w = ptr[value_start..i];
            const value = try unicode.wtf16LeToWtf8Alloc(allocator, value_w);
            errdefer allocator.free(value);

            i += 1; // skip over null byte

            try result.putMove(key, value);
        }
        return result;
    } else if (native_os == .wasi and !builtin.link_libc) {
        var environ_count: usize = undefined;
        var environ_buf_size: usize = undefined;

        const environ_sizes_get_ret = std.os.wasi.environ_sizes_get(&environ_count, &environ_buf_size);
        if (environ_sizes_get_ret != .SUCCESS) {
            return posix.unexpectedErrno(environ_sizes_get_ret);
        }

        if (environ_count == 0) {
            return result;
        }

        const environ = try allocator.alloc([*:0]u8, environ_count);
        defer allocator.free(environ);
        const environ_buf = try allocator.alloc(u8, environ_buf_size);
        defer allocator.free(environ_buf);

        const environ_get_ret = std.os.wasi.environ_get(environ.ptr, environ_buf.ptr);
        if (environ_get_ret != .SUCCESS) {
            return posix.unexpectedErrno(environ_get_ret);
        }

        for (environ) |env| {
            const pair = mem.sliceTo(env, 0);
            var parts = mem.splitScalar(u8, pair, '=');
            const key = parts.first();
            const value = parts.rest();
            try result.put(key, value);
        }
        return result;
    } else if (builtin.link_libc) {
        var ptr = std.c.environ;
        while (ptr[0]) |line| : (ptr += 1) {
            var line_i: usize = 0;
            while (line[line_i] != 0 and line[line_i] != '=') : (line_i += 1) {}
            const key = line[0..line_i];

            var end_i: usize = line_i;
            while (line[end_i] != 0) : (end_i += 1) {}
            const value = line[line_i + 1 .. end_i];

            try result.put(key, value);
        }
        return result;
    } else {
        for (std.os.environ) |line| {
            var line_i: usize = 0;
            while (line[line_i] != 0 and line[line_i] != '=') : (line_i += 1) {}
            const key = line[0..line_i];

            var end_i: usize = line_i;
            while (line[end_i] != 0) : (end_i += 1) {}
            const value = line[line_i + 1 .. end_i];

            try result.put(key, value);
        }
        return result;
    }
}  