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* "cat" breaks ANSI codes on Windows Terminal when piping stdout to python or golang
@ 2022-06-14  8:01 5990
  2022-06-14 10:47 ` Takashi Yano
  0 siblings, 1 reply; 6+ messages in thread
From: 5990 @ 2022-06-14  8:01 UTC (permalink / raw)
  To: cygwin

## Bug:
Piping the standard output of cat into the standard input of golang or python, makes the Windows Terminal render ANSI codes as arrows.

For example:
`\033[36m` turns into `←[36m` (or in base64'd UNICODE: `4oaQWzM2bQ==`)

## Environment:
- cat v8.26
- Windows Terminal v1.12.10982.0
- golang version go1.17.2 windows/amd64
- python v3.7.7

colors.go
```
package main

import "fmt"

const colorReset = "\033[0m"
const colorCyan = "\033[36m"

func main(){
  fmt.Print(string(colorCyan) + "golang-test" + string(colorReset) + "\n")
}
```


color.py
```
from lolpython import lol_py

lol_py("python-test")
```


domains.txt is an empty file (from my testing, the contents of domains.txt do not affect this bug)

## What works:
The following commands will successfuly output in cyan color
`go run color.go`
`go build color.go && color.exe`
`go build color.go && cat domains.txt | color.exe`
`go build color.go && echo a | color.exe`
`go build color.go && type domains.txt | color.exe`
`py -3.7 color.py`

## What triggers the bug:
`cat domains.txt | go run color.go`
OUTPUT: `←[36mgolang-test←[0m`

`cat domains.txt | py -3.7 color.py`
OUTPUT: `←[38;2;128;237;18mp←[0m←[38;2;139;231;12my←[0m←[38;2;150;225;8mt←[0m←[38;2;161;217;5mh←[0m←[38;2;172;209;2mo←[0m←[38;2;182;200;1mn←[0m←[38;2;192;190;1m-←[0m←[38;2;201;180;1mt←[0m←[38;2;210;170;3me←[0m←[38;2;218;159;5ms←[0m←[38;2;226;148;9mt←[0m`

Strangely enough, golang compiled executables work perfectly, but piping `cat domains.txt | go run color.go` does not work.
The workaround I had to go with is to use Windows's built-in `type` command instead of `cat`. This was a tricky bug to track-down so I hope this report helps hahah

- ItsIgnacioPortal

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-06-15  4:43 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-14  8:01 "cat" breaks ANSI codes on Windows Terminal when piping stdout to python or golang 5990
2022-06-14 10:47 ` Takashi Yano
2022-06-14 21:53   ` 5990
2022-06-14 21:56     ` 5990
2022-06-15  1:04       ` Takashi Yano
2022-06-15  4:42         ` Takashi Yano

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