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 #2875)

runtime/doc/eval.txt

@@ -1369,6 +1369,13 @@ $VAR			environment variable
 
 The String value of any environment variable.  When it is not defined, the
 result is an empty string.
+
+The functions `getenv()` and `setenv()` can also be used and work for
+environment variables with non-alphanumeric names.
+The function `environ()` can be used to get a Dict with all environment
+variables.
+
+
 						*expr-env-expand*
 Note that there is a difference between using $VAR directly and using
 expand("$VAR").  Using it directly will only expand environment variables that
@@ -2303,6 +2310,7 @@ did_filetype()			Number	|TRUE| if FileType autocmd event used
 diff_filler({lnum})		Number	diff filler lines about {lnum}
 diff_hlID({lnum}, {col})	Number	diff highlighting at {lnum}/{col}
 empty({expr})			Number	|TRUE| if {expr} is empty
+environ()			Dict	return environment variables
 escape({string}, {chars})	String	escape {chars} in {string} with '\'
 eval({string})			any	evaluate {string} into its value
 eventhandler()			Number	|TRUE| if inside an event handler
@@ -2360,6 +2368,7 @@ getcompletion({pat}, {type} [, {filtered}])
 				List	list of cmdline completion matches
 getcurpos()			List	position of the cursor
 getcwd([{winnr} [, {tabnr}]])	String	get the current working directory
+getenv({name})			String	return environment variable
 getfontname([{name}])		String	name of font being used
 getfperm({fname})		String	file permissions of file {fname}
 getfsize({fname})		Number	size in bytes of file {fname}
@@ -2568,6 +2577,7 @@ setbufvar({expr}, {varname}, {val})
 				none	set {varname} in buffer {expr} to {val}
 setcharsearch({dict})		Dict	set character search from {dict}
 setcmdpos({pos})		Number	set cursor position in command-line
+setenv({name}, {val})		none	set environment variable
 setfperm({fname}, {mode})	Number	set {fname} file permissions to {mode}
 setline({lnum}, {line})		Number	set line {lnum} to {line}
 setloclist({nr}, {list} [, {action} [, {what}]])
@@ -3905,6 +3915,14 @@ diff_hlID({lnum}, {col})				*diff_hlID()*
 		The highlight ID can be used with |synIDattr()| to obtain
 		syntax information about the highlighting.
 
+environ()						*environ()*
+		Return all of environment variables as dictionary. You can
+		check if an environment variable exists like this: >
+			:echo has_key(environ(), 'HOME')
+<		Note that the variable name may be CamelCase; to ignore case
+		use this: >
+			:echo index(keys(environ()), 'HOME', 0, 1) != -1
+
 empty({expr})						*empty()*
 		Return the Number 1 if {expr} is empty, zero otherwise.
 		- A |List| or |Dictionary| is empty when it does not have any
@@ -4970,13 +4988,11 @@ getcwd([{winnr} [, {tabnr}]])
 			" Get the working directory of current tabpage
 			:echo getcwd(-1, 0)
 <
-getfsize({fname})					*getfsize()*
-		The result is a Number, which is the size in bytes of the
-		given file {fname}.
-		If {fname} is a directory, 0 is returned.
-		If the file {fname} can't be found, -1 is returned.
-		If the size of {fname} is too big to fit in a Number then -2
-		is returned.
+getenv({name})						*getenv()*
+		Return the value of environment variable {name}.
+		When the variable does not exist |v:null| is returned.  That
+		is different from a variable set to an empty string.
+		See also |expr-env|.
 
 getfontname([{name}])					*getfontname()*
 		Without an argument returns the name of the normal font being
@@ -5009,6 +5025,14 @@ getfperm({fname})					*getfperm()*
 
 		For setting permissions use |setfperm()|.
 
+getfsize({fname})					*getfsize()*
+		The result is a Number, which is the size in bytes of the
+		given file {fname}.
+		If {fname} is a directory, 0 is returned.
+		If the file {fname} can't be found, -1 is returned.
+		If the size of {fname} is too big to fit in a Number then -2
+		is returned.
+
 getftime({fname})					*getftime()*
 		The result is a Number, which is the last modification time of
 		the given file {fname}.  The value is measured as seconds
@@ -8012,6 +8036,11 @@ setcmdpos({pos})					*setcmdpos()*
 		Returns 0 when successful, 1 when not editing the command
 		line.
 
+setenv({name}, {val})						*setenv()*
+		Set environment variable {name} to {val}.
+		When {val} is |v:null| the environment variable is deleted.
+		See also |expr-env|.
+
 setfperm({fname}, {mode})				*setfperm()* *chmod*
 		Set the file permissions for {fname} to {mode}.
 		{mode} must be a string with 9 characters.  It is of the form

runtime/doc/usr_41.txt

@@ -774,6 +774,9 @@ System functions and manipulation of files:
 	rename()		rename a file
 	system()		get the result of a shell command as a string
 	systemlist()		get the result of a shell command as a list
+	environ()		get all environment variables
+	getenv()		get one environment variable
+	setenv()		set an environment variable
 	hostname()		name of the system
 	readfile()		read a file into a List of lines
 	readdir()		get a List of file names in a directory
@@ -903,6 +906,7 @@ GUI:						*gui-functions*
 	getwinposy()		Y position of the Vim window
 	balloon_show()		set the balloon content
 	balloon_split()		split a message for a balloon
+	balloon_gettext()	get the text in the balloon
 
 Vim server:					*server-functions*
 	serverlist()		return the list of server names

src/evalfunc.c

@@ -137,6 +137,7 @@ static void f_did_filetype(typval_T *argvars, typval_T *rettv);
 static void f_diff_filler(typval_T *argvars, typval_T *rettv);
 static void f_diff_hlID(typval_T *argvars, typval_T *rettv);
 static void f_empty(typval_T *argvars, typval_T *rettv);
+static void f_environ(typval_T *argvars, typval_T *rettv);
 static void f_escape(typval_T *argvars, typval_T *rettv);
 static void f_eval(typval_T *argvars, typval_T *rettv);
 static void f_eventhandler(typval_T *argvars, typval_T *rettv);
@@ -187,6 +188,7 @@ static void f_getcmdpos(typval_T *argvars, typval_T *rettv);
 static void f_getcmdtype(typval_T *argvars, typval_T *rettv);
 static void f_getcmdwintype(typval_T *argvars, typval_T *rettv);
 static void f_getcwd(typval_T *argvars, typval_T *rettv);
+static void f_getenv(typval_T *argvars, typval_T *rettv);
 static void f_getfontname(typval_T *argvars, typval_T *rettv);
 static void f_getfperm(typval_T *argvars, typval_T *rettv);
 static void f_getfsize(typval_T *argvars, typval_T *rettv);
@@ -365,6 +367,7 @@ static void f_setbufline(typval_T *argvars, typval_T *rettv);
 static void f_setbufvar(typval_T *argvars, typval_T *rettv);
 static void f_setcharsearch(typval_T *argvars, typval_T *rettv);
 static void f_setcmdpos(typval_T *argvars, typval_T *rettv);
+static void f_setenv(typval_T *argvars, typval_T *rettv);
 static void f_setfperm(typval_T *argvars, typval_T *rettv);
 static void f_setline(typval_T *argvars, typval_T *rettv);
 static void f_setloclist(typval_T *argvars, typval_T *rettv);
@@ -629,6 +632,7 @@ static struct fst
     {"diff_filler",	1, 1, f_diff_filler},
     {"diff_hlID",	2, 2, f_diff_hlID},
     {"empty",		1, 1, f_empty},
+    {"environ",		0, 0, f_environ},
     {"escape",		2, 2, f_escape},
     {"eval",		1, 1, f_eval},
     {"eventhandler",	0, 0, f_eventhandler},
@@ -681,6 +685,7 @@ static struct fst
 #endif
     {"getcurpos",	0, 0, f_getcurpos},
     {"getcwd",		0, 2, f_getcwd},
+    {"getenv",		1, 1, f_getenv},
     {"getfontname",	0, 1, f_getfontname},
     {"getfperm",	1, 1, f_getfperm},
     {"getfsize",	1, 1, f_getfsize},
@@ -873,6 +878,7 @@ static struct fst
     {"setbufvar",	3, 3, f_setbufvar},
     {"setcharsearch",	1, 1, f_setcharsearch},
     {"setcmdpos",	1, 1, f_setcmdpos},
+    {"setenv",		2, 2, f_setenv},
     {"setfperm",	2, 2, f_setfperm},
     {"setline",		2, 2, f_setline},
     {"setloclist",	2, 4, f_setloclist},
@@ -3339,6 +3345,59 @@ f_empty(typval_T *argvars, typval_T *rettv)
     rettv->vval.v_number = n;
 }
 
+/*
+ * "environ()" function
+ */
+    static void
+f_environ(typval_T *argvars UNUSED, typval_T *rettv)
+{
+#if !defined(AMIGA)
+    int			i = 0;
+    char_u		*entry, *value;
+# ifdef MSWIN
+    extern wchar_t	**_wenviron;
+# else
+    extern char		**environ;
+# endif
+
+    if (rettv_dict_alloc(rettv) != OK)
+	return;
+
+# ifdef MSWIN
+    if (*_wenviron == NULL)
+	return;
+# else
+    if (*environ == NULL)
+	return;
+# endif
+
+    for (i = 0; ; ++i)
+    {
+# ifdef MSWIN
+	short_u		*p;
+
+	if ((p = (short_u *)_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 (entry == NULL) // out of memory
+	    return;
+	if ((value = vim_strchr(entry, '=')) == NULL)
+	{
+	    vim_free(entry);
+	    continue;
+	}
+	*value++ = NUL;
+	dict_add_string(rettv->vval.v_dict, (char *)entry, value);
+	vim_free(entry);
+    }
+#endif
+}
+
 /*
  * "escape({string}, {chars})" function
  */
@@ -5260,6 +5319,27 @@ f_getcwd(typval_T *argvars, typval_T *rettv)
 #endif
 }
 
+/*
+ * "getenv()" function
+ */
+    static void
+f_getenv(typval_T *argvars, typval_T *rettv)
+{
+    int	    mustfree = FALSE;
+    char_u  *p = vim_getenv(tv_get_string(&argvars[0]), &mustfree);
+
+    if (p == NULL)
+    {
+	rettv->v_type = VAR_SPECIAL;
+	rettv->vval.v_number = VVAL_NULL;
+	return;
+    }
+    if (!mustfree)
+	p = vim_strsave(p);
+    rettv->vval.v_string = p;
+    rettv->v_type = VAR_STRING;
+}
+
 /*
  * "getfontname()" function
  */
@@ -11424,6 +11504,23 @@ f_setcmdpos(typval_T *argvars, typval_T *rettv)
 	rettv->vval.v_number = set_cmdline_pos(pos);
 }
 
+/*
+ * "setenv()" function
+ */
+    static void
+f_setenv(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    char_u   namebuf[NUMBUFLEN];
+    char_u   valbuf[NUMBUFLEN];
+    char_u  *name = tv_get_string_buf(&argvars[0], namebuf);
+
+    if (argvars[1].v_type == VAR_SPECIAL
+				      && argvars[1].vval.v_number == VVAL_NULL)
+	vim_unsetenv(name);
+    else
+	vim_setenv(name, tv_get_string_buf(&argvars[1], valbuf));
+}
+
 /*
  * "setfperm({fname}, {mode})" function
  */

src/testdir/Make_all.mak

@@ -104,6 +104,7 @@ NEW_TESTS = \
 	test_erasebackword \
 	test_escaped_glob \
 	test_eval_stuff \
+	test_environ \
 	test_ex_equal \
 	test_ex_undo \
 	test_ex_z \
@@ -320,6 +321,7 @@ NEW_TESTS_RES = \
 	test_digraph.res \
 	test_display.res \
 	test_edit.res \
+	test_environ.res \
 	test_erasebackword.res \
 	test_escaped_glob.res \
 	test_eval_stuff.res \

src/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

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1305,
 /**/
     1304,
 /**/