[PATCH v3 0/1] MR7252: cmd: add support for right-to-left handle redirection (2<&1)

[Damjan Jovanovic (＠dj)]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=57795

Closes #57795

--
  v3: cmd: add support for right-to-left handle redirection (2<&1)

https://gitlab.winehq.org/wine/wine/-/merge_requests/7252

[PATCH v3 1/1] cmd: add support for right-to-left handle redirection (2<&1)

[Damjan Jovanovic]

From: Damjan Jovanovic

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=57795
---
 programs/cmd/tests/test_builtins.cmd     |  5 +++++
 programs/cmd/tests/test_builtins.cmd.exp |  3 +++
 programs/cmd/wcmdmain.c                  | 18 +++++++++++++++---
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/programs/cmd/tests/test_builtins.cmd b/programs/cmd/tests/test_builtins.cmd
index 8552d51930a..a38456d95c5 100644
--- a/programs/cmd/tests/test_builtins.cmd
+++ b/programs/cmd/tests/test_builtins.cmd
@@ -176,6 +176,11 @@ del foo
 echo foo> foo
 echo foo7 7>> foo || (echo not supported & del foo)
 if exist foo (type foo) else echo not supported
+echo --- right-to-left redirection
+echo foo 1>foo-out 2>foo-err 1<&2
+findstr foo foo-out >nul 2>nul & if errorlevel 1 (echo not in foo-out) else echo in foo-out
+findstr foo foo-err >nul 2>nul & if errorlevel 1 (echo not in foo-err) else echo in foo-err
+erase /q foo-out foo-err
 echo --- redirect at beginning of line
> foo (echo foo)

type foo
diff --git a/programs/cmd/tests/test_builtins.cmd.exp b/programs/cmd/tests/test_builtins.cmd.exp
index 292c24985e8..42cd415e147 100644
--- a/programs/cmd/tests/test_builtins.cmd.exp
+++ b/programs/cmd/tests/test_builtins.cmd.exp
@@ -204,6 +204,9 @@ food2
 food21
 foo7@space@@space@@or_broken@not supported@space@
 foo@or_broken@not supported
+--- right-to-left redirection
+not in foo-out
+in foo-err
 --- redirect at beginning of line
 foo
 foo1
diff --git a/programs/cmd/wcmdmain.c b/programs/cmd/wcmdmain.c
index b19f8453438..3e248a6d36a 100644
--- a/programs/cmd/wcmdmain.c
+++ b/programs/cmd/wcmdmain.c
@@ -2627,8 +2627,20 @@ static void lexer_push_command(struct node_builder *builder,

if (*p == L'<')
             {
-                filename = WCMD_parameter(p + 1, 0, NULL, FALSE, FALSE);
-                tkn_pmt.redirection = redirection_create_file(REDIR_READ_FROM, 0, filename);
+                unsigned fd = 0;
+
+                if (p > redirs && p[-1] >= L'0' && p[-1] <= L'9') fd = p[-1] - L'0';
+                p++;
+                if (*p == L'&' && (p[1] >= L'0' && p[1] <= L'9'))
+                {
+                    tkn_pmt.redirection = redirection_create_clone(fd, p[1] - L'0');
+                    p++;
+                }
+                else
+                {
+                    filename = WCMD_parameter(p + 1, 0, NULL, FALSE, FALSE);
+                    tkn_pmt.redirection = redirection_create_file(REDIR_READ_FROM, 0, filename);
+                }
             }
             else
             {
@@ -2984,7 +2996,7 @@ enum read_parse_line WCMD_ReadAndParseLine(const WCHAR *optionalcmd, CMD_NODE **

/* If a redirect is immediately followed by '&' (ie. 2>&1) then
                     do not process that ampersand as an AND operator */
-                if (thisChar == '>' && *(curPos+1) == '&') {
+                if ((thisChar == '>' || thisChar == '<') && *(curPos+1) == '&') {
                     curCopyTo[(*curLen)++] = *(curPos+1);
                     curPos++;
                 }

[Damjan Jovanovic (＠dj)]

On Tue Feb  4 17:02:04 2025 +0000, eric pouech wrote:
> we could perhaps test that the cloning of the handle actually took place
> your test just shows that the parsing succeeds but nothing is actually
> written to 2
> something like would do
> `dir /Z > foo 2<&1`
> `findstr . foo > NUL & if errorlevel 1 (echo not redirected) else echo redirected`

Thank you, I've updated the test to check whether redirection to stderr happens.

[eric pouech (＠epo)]

thanks for the update, your new first test is way cleaner...

(just trying to simplify at most the tests and avoid calling external findstr, you could do

`type foo-out 2> NUL || echo good`

`type foo-err 2> NUL || echo bad`

should output

`good`

`foo`

(does work on native, should work on wine but didn't test it though)