starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-09-25 00:15:10 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

Output from WSL command pipeline is randomly truncated #1441

New Issue
Closed
opened 2026-01-30 22:27:10 +00:00 by claunia · 6 comments
claunia commented 2026-01-30 22:27:10 +00:00
Owner
Copy Link

Originally created by @petsuter on GitHub (May 31, 2019).

Environment

Windows build number: 10.0.17134.765

Steps to reproduce

  • Open cmd.exe and enter the following commands:
mkdir test && cd test
FOR /L %i IN (100,1,999) DO echo %i >> data.txt
FOR /L %i IN (1,1,100) DO copy data.txt data%i.txt
wsl cat * | wsl sort | wsl uniq

Repeat the last line multiple times to repeat the problem with randomly different behavior.

Expected behavior

After the last command the terminal should display all integers from 100 to 999.

Actual behavior

After the last command the terminal only displays all integers from 100 to some random integer smaller than 999 (e.g. 978). Sometimes the last integer is not shown completely (e.g. only "97" instead of "978").

The output is truncated? One of the programs in the pipeline is aborted early? It might be a timing issue? Repeating the last command often results in the same "random" number, but sometimes it gets stops later / earlier.

Using different counts (e.g. 100 to 400 instead of 100 to 999) the problem also occurs.

Using slightly different commands the problem does not occur, e.g. this works correctly:

wsl
cat * | sort | uniq
Originally created by @petsuter on GitHub (May 31, 2019). # Environment ```none Windows build number: 10.0.17134.765 ``` # Steps to reproduce * Open `cmd.exe` and enter the following commands: ``` mkdir test && cd test FOR /L %i IN (100,1,999) DO echo %i >> data.txt FOR /L %i IN (1,1,100) DO copy data.txt data%i.txt wsl cat * | wsl sort | wsl uniq ``` Repeat the last line multiple times to repeat the problem with randomly different behavior. # Expected behavior After the last command the terminal should display all integers from 100 to 999. # Actual behavior After the last command the terminal only displays all integers from 100 to some random integer smaller than 999 (e.g. 978). Sometimes the last integer is not shown completely (e.g. only "97" instead of "978"). ---- The output is truncated? One of the programs in the pipeline is aborted early? It might be a timing issue? Repeating the last command often results in the same "random" number, but sometimes it gets stops later / earlier. Using different counts (e.g. 100 to 400 instead of 100 to 999) the problem also occurs. Using slightly different commands the problem does not occur, e.g. this works correctly: ``` wsl cat * | sort | uniq ```
claunia added the Product-WSLArea-OutputIssue-BugResolution-External labels 2026-01-30 22:27:10 +00:00
claunia commented 2026-01-30 22:27:11 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (May 31, 2019):

@benhillis Is this some sort of WSL bug?

It seems to occur regardless of conhost vs terminal. The fact that running cat * | sort | uniq without starting wsl each time makes me think it might be just an issue in WSL

@zadjii-msft commented on GitHub (May 31, 2019): @benhillis Is this some sort of WSL bug? It seems to occur regardless of conhost vs terminal. The fact that running `cat * | sort | uniq` without starting wsl each time makes me think it might be just an issue in WSL
claunia commented 2026-01-30 22:27:12 +00:00
Author
Owner
Copy Link

@benhillis commented on GitHub (May 31, 2019):

I have seen instances of this in the past, let me see if I can still repro...

@benhillis commented on GitHub (May 31, 2019): I have seen instances of this in the past, let me see if I can still repro...
claunia commented 2026-01-30 22:27:12 +00:00
Author
Owner
Copy Link

@DHowett-MSFT commented on GitHub (Jun 2, 2019):

This report is on 17134, and it seems to be related to piping from WSL to WSL. I'm going to say with 100% certainty that it's not a Console bug. 😄

@DHowett-MSFT commented on GitHub (Jun 2, 2019): This report is on _17134_, and it seems to be related to piping from WSL to WSL. I'm going to say with 100% certainty that it's not a Console bug. :smile:
claunia commented 2026-01-30 22:27:12 +00:00
Author
Owner
Copy Link

@petsuter commented on GitHub (Jun 2, 2019):

Thanks all for checking. 👍 Should I reopen this issue somewhere else?

(I originally intended to open it at https://github.com/microsoft/WSL/issues/new but there it says:

If this is a console issue (a problem with layout, rendering, colors, etc.), please post to the console issue tracker.

So I did that here instead. From outside it's difficult to know if this is a rendering issue or not. For all I know it could be a bug in cat, sort, uniq, wsl, cmd or whatever else is internally involved with piping. 🤔)

Please let me know or just reopen the issue wherever the appropriate place is, thanks!

@petsuter commented on GitHub (Jun 2, 2019): Thanks all for checking. 👍 Should I reopen this issue somewhere else? (I originally intended to open it at https://github.com/microsoft/WSL/issues/new but there it says: > If this is a console issue (a problem with layout, rendering, colors, etc.), please post to the [console issue tracker](https://github.com/microsoft/console/issues). So I did that here instead. From outside it's difficult to know if this is a rendering issue or not. For all I know it could be a bug in `cat`, `sort`, `uniq`, `wsl`, `cmd` or whatever else is internally involved with piping. 🤔) Please let me know or just reopen the issue wherever the appropriate place is, thanks!
claunia commented 2026-01-30 22:27:12 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (Jun 3, 2019):

Yea, sometimes it's really hard to tell externally if something like this is better suited for the WSL repo or the console repo. In this case, this is probably a bug with WSL itself, so it probably belongs in Microsoft/WSL

@zadjii-msft commented on GitHub (Jun 3, 2019): Yea, sometimes it's really hard to tell externally if something like this is better suited for the WSL repo or the console repo. In this case, this is probably a bug with WSL itself, so it probably belongs in [Microsoft/WSL](https://www.github.com/Microsoft/WSL)
claunia commented 2026-01-30 22:27:13 +00:00
Author
Owner
Copy Link

@petsuter commented on GitHub (Jun 3, 2019):

OK thanks, I opened a new issue there.

@petsuter commented on GitHub (Jun 3, 2019): OK thanks, I opened a [new issue there](https://github.com/microsoft/WSL/issues/4082).
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 Area-Output Issue-Bug Product-WSL Resolution-External
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#1441
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?