os: implement os.environ() (part 2/2) (#3971)

vlib/os/environment.v

@@ -0,0 +1,80 @@
+// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module os
+
+fn C.getenv(byteptr) &char
+// C.GetEnvironmentStringsW & C.FreeEnvironmentStringsW are defined only on windows
+fn C.GetEnvironmentStringsW() &u16
+
+
+fn C.FreeEnvironmentStringsW(&u16) int
+// `getenv` returns the value of the environment variable named by the key.
+pub fn getenv(key string) string {
+	$if windows {
+		s := C._wgetenv(key.to_wide())
+		if s == 0 {
+			return ''
+		}
+		return string_from_wide(s)
+	} $else {
+		s := C.getenv(key.str)
+		if s == 0 {
+			return ''
+		}
+		// NB: C.getenv *requires* that the result be copied.
+		return cstring_to_vstring(byteptr(s))
+	}
+}
+
+// os.setenv sets the value of an environment variable with `name` to `value`.
+pub fn setenv(name string, value string, overwrite bool) int {
+	$if windows {
+		format := '$name=$value'
+		if overwrite {
+			return C._putenv(format.str)
+		}
+		return -1
+	} $else {
+		return C.setenv(name.str, value.str, overwrite)
+	}
+}
+
+// os.unsetenv clears an environment variable with `name`.
+pub fn unsetenv(name string) int {
+	$if windows {
+		format := '${name}='
+		return C._putenv(format.str)
+	} $else {
+		return C.unsetenv(name.str)
+	}
+}
+
+// See: https://linux.die.net/man/5/environ for unix platforms.
+// See: https://docs.microsoft.com/bg-bg/windows/win32/api/processenv/nf-processenv-getenvironmentstrings
+// os.environ returns a map of all the current environment variables
+pub fn environ() map[string]string {
+	mut res := map[string]string
+	$if windows {
+		mut estrings := C.GetEnvironmentStringsW()
+		mut eline := ''
+		for c := estrings; *c != 0; c = c + eline.len + 1 {
+			eline = string_from_wide(c)
+			eq_index := eline.index_byte(`=`)
+			if eq_index > 0 {
+				res[eline[0..eq_index]] = eline[eq_index + 1..]
+			}
+		}
+		C.FreeEnvironmentStringsW(estrings)
+	} $else {
+		e := &byteptr(&C.environ)
+		for i := 0; !isnil(e[i]); i++ {
+			eline := cstring_to_vstring(e[i])
+			eq_index := eline.index_byte(`=`)
+			if eq_index > 0 {
+				res[eline[0..eq_index]] = eline[eq_index + 1..]
+			}
+		}
+	}
+	return res
+}

vlib/os/environment_test.v

@@ -0,0 +1,36 @@
+import os
+
+fn test_getenv() {
+	// VEXE is set by the V builtin test runner
+	assert os.getenv('VEXE').len > 0
+	assert os.getenv('PATH').len > 0
+}
+
+fn test_setenv() {
+	os.setenv('foo', 'bar', true)
+	assert os.getenv('foo') == 'bar'
+	// `setenv` should not set if `overwrite` is false
+	os.setenv('foo', 'bar2', false)
+	assert os.getenv('foo') == 'bar'
+	// `setenv` should overwrite if `overwrite` is true
+	os.setenv('foo', 'bar2', true)
+	assert os.getenv('foo') == 'bar2'
+}
+
+fn test_unsetenv() {
+	os.setenv('foo', 'bar', true)
+	os.unsetenv('foo')
+	assert os.getenv('foo') == ''
+}
+
+fn test_environ() {
+	os.setenv('myvar1', 'bar1', true)
+	os.setenv('myvar2', 'bar2', true)
+	assert os.getenv('myvar1') == 'bar1'
+	assert os.getenv('myvar2') == 'bar2'
+	assert os.getenv('myvar_not_defined') == ''
+	all := os.environ()
+	assert all['myvar1'] == 'bar1'
+	assert all['myvar2'] == 'bar2'
+	assert all['myvar_not_defined'] == ''
+}

vlib/os/os.v

@@ -65,9 +65,6 @@ fn C.getline(voidptr, voidptr, voidptr) int
 fn C.ftell(fp voidptr) int
 
 
-fn C.getenv(byteptr) &char
-
-
 fn C.sigaction(int, voidptr, int)
 
 
@@ -507,45 +504,6 @@ pub fn sigint_to_signal_name(si int) string {
 	return 'unknown'
 }
 
-// `getenv` returns the value of the environment variable named by the key.
-pub fn getenv(key string) string {
-	$if windows {
-		s := C._wgetenv(key.to_wide())
-		if s == 0 {
-			return ''
-		}
-		return string_from_wide(s)
-	} $else {
-		s := C.getenv(key.str)
-		if s == 0 {
-			return ''
-		}
-		// NB: C.getenv *requires* that the result be copied.
-		return cstring_to_vstring(byteptr(s))
-	}
-}
-
-pub fn setenv(name string, value string, overwrite bool) int {
-	$if windows {
-		format := '$name=$value'
-		if overwrite {
-			return C._putenv(format.str)
-		}
-		return -1
-	} $else {
-		return C.setenv(name.str, value.str, overwrite)
-	}
-}
-
-pub fn unsetenv(name string) int {
-	$if windows {
-		format := '${name}='
-		return C._putenv(format.str)
-	} $else {
-		return C.unsetenv(name.str)
-	}
-}
-
 const (
 	F_OK = 0
 	X_OK = 1

vlib/os/os_test.v

@@ -8,25 +8,6 @@ fn testsuite_end() {
 	cleanup_leftovers()
 }
 
-fn test_setenv() {
-  os.setenv('foo', 'bar', true)
-  assert os.getenv('foo') == 'bar'
-
-  // `setenv` should not set if `overwrite` is false
-  os.setenv('foo', 'bar2', false)
-  assert os.getenv('foo') == 'bar'
-
-  // `setenv` should overwrite if `overwrite` is true
-  os.setenv('foo', 'bar2', true)
-  assert os.getenv('foo') == 'bar2'
-}
-
-fn test_unsetenv() {
-  os.setenv('foo', 'bar', true)
-  os.unsetenv('foo')
-  assert os.getenv('foo') == ''
-}
-
 fn test_open_file() {
   filename := './test1.txt'
   hello := 'hello world!'