starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-04 05:35:20 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

CMD inconsistent parsing behavior when the /C argument is present #13042

New Issue
Open
opened 2026-01-31 03:32:08 +00:00 by claunia · 0 comments
claunia commented 2026-01-31 03:32:08 +00:00
Owner
Copy Link

Originally created by @snake-4 on GitHub (Mar 15, 2021).

Environment

Windows build number: Microsoft Windows [Version 10.0.19042.867]
Windows Terminal version (if applicable): N/A

Any other software? A simple test app written in C.

Steps to reproduce

Compile the following C program with any compiler of your choice.

#include <stdio.h>
#include <Windows.h>

int main(int argc, char* argv[])
{
	HANDLE hComPort = CreateFileW(L"\\\\.\\COM9", GENERIC_READ | GENERIC_WRITE, 0, NULL,
		OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
	printf("Can open: %s\nGetLastError(): %x", (hComPort == INVALID_HANDLE_VALUE ? "NO" : "YES"), GetLastError());
}

Now run the program like this cmd /C "testprog COM9" and it won't be able to open the port and the last error will be 5.
But if you run the program without any arguments, it will be able to open the port just fine. I think what's happening here is that the cmd is somehow opening the port itself.

Expected behavior

Running the program mentioned above with a command like this cmd /C "testprog COM9" should be able to open the port.

Actual behavior

There are two possible outcomes for every test here, either it fails and the last error gets set to 5 or it works fine.
Note: I've performed the following test cases multiple times and tried to restart my computer and each time the outcome was the same.

cmd /C "testprog dummyarg1" works
cmd /C "testprog dummyarg1 COM9" works
cmd /C "testprog dummyarg1 "COM9"" fails
cmd /C "testprog -dummyarg1 COM9" fails

cmd /C "testprog COM9" fails
testprog COM9 works

cmd /e off /C "testprog COM9" fails (*)
cmd /e off /e off /C "testprog COM9" works (*)
cmd /v off /C "testprog COM9" fails (*)
cmd /v off /v off /C "testprog COM9" works (*)

(*) These starred test cases are the most interesting ones because I think they clearly indicate a problem with the cmd's parsing.

Originally created by @snake-4 on GitHub (Mar 15, 2021). <!-- 🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨 I ACKNOWLEDGE THE FOLLOWING BEFORE PROCEEDING: 1. If I delete this entire template and go my own path, the core team may close my issue without further explanation or engagement. 2. If I list multiple bugs/concerns in this one issue, the core team may close my issue without further explanation or engagement. 3. If I write an issue that has many duplicates, the core team may close my issue without further explanation or engagement (and without necessarily spending time to find the exact duplicate ID number). 4. If I leave the title incomplete when filing the issue, the core team may close my issue without further explanation or engagement. 5. If I file something completely blank in the body, the core team may close my issue without further explanation or engagement. All good? Then proceed! --> <!-- This bug tracker is monitored by Windows Terminal development team and other technical folks. **Important: When reporting BSODs or security issues, DO NOT attach memory dumps, logs, or traces to Github issues**. Instead, send dumps/traces to secure@microsoft.com, referencing this GitHub issue. If this is an application crash, please also provide a Feedback Hub submission link so we can find your diagnostic data on the backend. Use the category "Apps > Windows Terminal (Preview)" and choose "Share My Feedback" after submission to get the link. Please use this form and describe your issue, concisely but precisely, with as much detail as possible. --> # Environment ```none Windows build number: Microsoft Windows [Version 10.0.19042.867] Windows Terminal version (if applicable): N/A Any other software? A simple test app written in C. ``` # Steps to reproduce Compile the following C program with any compiler of your choice. ```C #include <stdio.h> #include <Windows.h> int main(int argc, char* argv[]) { HANDLE hComPort = CreateFileW(L"\\\\.\\COM9", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); printf("Can open: %s\nGetLastError(): %x", (hComPort == INVALID_HANDLE_VALUE ? "NO" : "YES"), GetLastError()); } ``` Now run the program like this `cmd /C "testprog COM9"` and it won't be able to open the port and the last error will be `5`. But if you run the program without any arguments, it will be able to open the port just fine. I think what's happening here is that the cmd is somehow opening the port itself. <!-- A description of how to trigger this bug. --> # Expected behavior Running the program mentioned above with a command like this `cmd /C "testprog COM9"` should be able to open the port. <!-- A description of what you're expecting, possibly containing screenshots or reference material. --> # Actual behavior There are two possible outcomes for every test here, either it fails and the last error gets set to `5` or it works fine. Note: I've performed the following test cases multiple times and tried to restart my computer and each time the outcome was the same. `cmd /C "testprog dummyarg1"` works `cmd /C "testprog dummyarg1 COM9"` works `cmd /C "testprog dummyarg1 "COM9""` fails `cmd /C "testprog -dummyarg1 COM9"` fails `cmd /C "testprog COM9"` fails `testprog COM9` works `cmd /e off /C "testprog COM9"` fails (\*) `cmd /e off /e off /C "testprog COM9"` works (\*) `cmd /v off /C "testprog COM9"` fails (\*) `cmd /v off /v off /C "testprog COM9"` works (\*) (*) These starred test cases are the most interesting ones because I think they clearly indicate a problem with the cmd's parsing. <!-- What's actually happening? -->
claunia added the Needs-TriageNeeds-Tag-FixNeeds-AttentionProduct-Cmd.exe labels 2026-01-31 03:32:09 +00:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
⛺ Reserved
A11yCO
A11yMAS
A11ySev1
A11ySev2
A11ySev3
A11yTTValidated
A11yUsable
A11yVoiceAccess
A11yWCAG
Area-Accessibility
Area-AtlasEngine
Area-AzureShell
Area-Build
Area-Build
Area-Chat
Area-CmdPal
Area-CodeHealth
Area-Commandline
Area-CookedRead
Area-DefApp
Area-Extensibility
Area-Fonts
Area-GroupPolicy
Area-i18n
Area-Input
Area-Interaction
Area-Interop
Area-Localization
Area-Output
Area-Performance
Area-Portable
Area-Quality
Area-Remoting
Area-Rendering
Area-Schema
Area-Server
Area-Settings
Area-SettingsUI
Area-ShellExtension
Area-ShellExtension
Area-ShellExtension
Area-Suggestions
Area-Suggestions
Area-TerminalConnection
Area-TerminalControl
Area-Theming
Area-UserInterface
Area-VT
Area-Windowing
Area-WPFControl
AutoMerge
Blocking-Ingestion
Culprit-Centennial
Culprit-WinUI
Disability-All
Disability-Blind
Disability-LowVision
Disability-Mobility
External-Blocked-WinUI3
Fixed
Gathering-Data
good first issue
HCL-E+D
HCL-WindowsTerminal
Help Wanted
Impact-Compatibility
Impact-Compliance
Impact-Correctness
Impact-Visual
In-PR
InclusionBacklog
InclusionBacklog-Windows TerminalWin32
InclusionCommitted-202206
Issue-Bug
Issue-Docs
Issue-Feature
Issue-Feature
Issue-Question
Issue-Samples
Issue-Scenario
Issue-Task
Needs-Attention
Needs-Author-Feedback
Needs-Bisect
Needs-Discussion
Needs-Repro
Needs-Tag-Fix
Needs-Tag-Fix
Needs-Triage
No-Recent-Activity
Priority-0
Priority-1
Priority-2
Priority-3
Product-Cmd.exe
Product-Colortool
Product-Colortool
Product-Colortool
Product-Conhost
Product-Conpty
Product-Meta
Product-Powershell
Product-Terminal
Product-WSL
pull-request
Mirrored from GitHub Pull Request
 Resolution-Answered
Resolution-By-Design
Resolution-Duplicate
Resolution-External
Resolution-Fix-Available
Resolution-Fix-Committed
Resolution-No-Repro
Resolution-Won't-Fix
Severity-Blocking
Severity-Crash
Severity-DataLoss
spam
this-will-be-a-breaking-change
Tracking-External
WindowsTerminal_Win32
Work-Item
zAskModeBug
zInbox-Bug
No Label Needs-Attention Needs-Tag-Fix Needs-Triage Product-Cmd.exe
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
claunia
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/terminal#13042
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?