vim-patch:8.1.1305: there is no easy way to manipulate environment variables

Problem:    There is no easy way to manipulate environment variables.
Solution:   Add environ(), getenv() and setenv(). (Yasuhiro Matsumoto,
            closes vim/vim#2875)
691ddeefb5

src/nvim/eval.c

@@ -8495,6 +8495,54 @@ static void f_empty(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   rettv->vval.v_number = n;
 }
 
+/// "environ()" function
+static void f_environ(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+  int i = 0;
+  char_u *entry, *value;
+# ifdef WIN32
+  extern wchar_t **_wenviron;
+# else
+  extern char **environ;
+# endif
+
+  tv_dict_alloc_ret(rettv);
+
+# ifdef WIN32
+  if (*_wenviron == NULL) {
+    return;
+  }
+# else
+  if (*environ == NULL) {
+    return;
+  }
+# endif
+
+  for (i = 0; ; i++) {
+# ifdef WIN32
+    uint16_t *p;
+
+    if ((p = (uint16_t *)_wenviron[i]) == NULL) {
+      return;
+    }
+    entry = utf16_to_enc(p, NULL);
+# else
+    if ((entry = (char_u *)environ[i]) == NULL) {
+      return;
+    }
+    entry = vim_strsave(entry);
+# endif
+    if ((value = vim_strchr(entry, '=')) == NULL) {
+      xfree(entry);
+      continue;
+    }
+    *value++ = NUL;
+    tv_dict_add_str(rettv->vval.v_dict, (char *)entry, STRLEN((char *)entry),
+                    (const char *)value);
+    xfree(entry);
+  }
+}
+
 /*
  * "escape({string}, {chars})" function
  */
@@ -8508,6 +8556,21 @@ static void f_escape(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   rettv->v_type = VAR_STRING;
 }
 
+/// "getenv()" function
+static void f_getenv(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+  char_u *p = (char_u *)vim_getenv(tv_get_string(&argvars[0]));
+
+  if (p == NULL || *p == NUL) {
+    rettv->v_type = VAR_SPECIAL;
+    rettv->vval.v_number = kSpecialVarNull;
+    return;
+  }
+  p = vim_strsave(p);
+  rettv->vval.v_string = p;
+  rettv->v_type = VAR_STRING;
+}
+
 /*
  * "eval()" function
  */
@@ -15319,6 +15382,20 @@ static void f_setcmdpos(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   }
 }
 
+/// "setenv()" function
+static void f_setenv(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+  char namebuf[NUMBUFLEN];
+  char valbuf[NUMBUFLEN];
+  const char *name = tv_get_string_buf(&argvars[0], namebuf);
+
+  if (argvars[1].v_type == VAR_SPECIAL
+      && argvars[1].vval.v_number == kSpecialVarNull) {
+    os_unsetenv(name);
+  } else {
+    vim_setenv(name, tv_get_string_buf(&argvars[1], valbuf));
+  }
+}
 
 /// "setfperm({fname}, {mode})" function
 static void f_setfperm(typval_T *argvars, typval_T *rettv, FunPtr fptr)

src/nvim/eval.lua

@@ -89,6 +89,7 @@ return {
     diff_filler={args=1},
     diff_hlID={args=2},
     empty={args=1},
+    environ={},
     escape={args=2},
     eval={args=1},
     eventhandler={},
@@ -135,6 +136,7 @@ return {
     getcompletion={args={2, 3}},
     getcurpos={},
     getcwd={args={0,2}},
+    getenv={args={1}},
     getfontname={args={0, 1}},
     getfperm={args=1},
     getfsize={args=1},
@@ -274,6 +276,7 @@ return {
     setbufvar={args=3},
     setcharsearch={args=1},
     setcmdpos={args=1},
+    setenv={args=2},
     setfperm={args=2},
     setline={args=2},
     setloclist={args={2, 4}},

src/nvim/testdir/test_environ.vim

@@ -0,0 +1,44 @@
+scriptencoding utf-8
+
+func Test_environ()
+  unlet! $TESTENV
+  call assert_equal(0, has_key(environ(), 'TESTENV'))
+  let $TESTENV = 'foo'
+  call assert_equal(1, has_key(environ(), 'TESTENV'))
+  let $TESTENV = 'こんにちわ'
+  call assert_equal('こんにちわ', environ()['TESTENV'])
+endfunc
+
+func Test_getenv()
+  unlet! $TESTENV
+  call assert_equal(v:null, getenv('TESTENV'))
+  let $TESTENV = 'foo'
+  call assert_equal('foo', getenv('TESTENV'))
+endfunc
+
+func Test_setenv()
+  unlet! $TESTENV
+  call setenv('TEST ENV', 'foo')
+  call assert_equal('foo', getenv('TEST ENV'))
+  call setenv('TEST ENV', v:null)
+  call assert_equal(v:null, getenv('TEST ENV'))
+endfunc
+
+func Test_external_env()
+  call setenv('FOO', 'HelloWorld')
+  if has('win32')
+    let result = system('echo %FOO%')
+  else
+    let result = system('echo $FOO')
+  endif
+  let result = substitute(result, '[ \r\n]', '', 'g')
+  call assert_equal('HelloWorld', result)
+
+  call setenv('FOO', v:null)
+  if has('win32')
+    let result = system('set | grep ^FOO=')
+  else
+    let result = system('env | grep ^FOO=')
+  endif
+  call assert_equal('', result)
+endfunc