Unknown escape sequences cause short write

[johnSchnake]

Problem was discovered when using golangs ssh package. If an application tries to output escape sequences not recognized by ansicolor (e.g. if $TERM=xterm and you run top) then a short write error occurs and the stdout pipe would break (though the connection and stdin pipe still function).

Preferably, the unrecognized sequences would just be placed into the buffer untouched.

[shiena]

@johnSchnake I made the PR #8 Is the problem still remains?

[fatih]

@shiena is there anything I should be aware for the color (https://github.com/fatih/color) package?

[shiena]

@fatih Maybe, there is no problem. The following is a simple difference. Please note the divided escape sequence and the non-color escape sequence.

package main

import (
    "fmt"
    "io"
    "os"

    "github.com/shiena/ansicolor"
)

func main() {
    outputEscseq(ansicolor.NewAnsiColorWriter(os.Stdout))
    outputEscseq(ansicolor.NewModeAnsiColorWriter(os.Stdout, ansicolor.OutputNonColorEscSeq))
}

func outputEscseq(w io.Writer) {
    fmt.Fprint(w, "\x1b[31m")
    fmt.Fprint(w, "fg red,")

    fmt.Fprint(w, "\x1b")
    fmt.Fprint(w, "[")
    fmt.Fprint(w, "3")
    fmt.Fprint(w, "2")
    fmt.Fprint(w, "m") // divided escape sequence
    fmt.Fprint(w, "fg green,")

    fmt.Fprint(w, "\x1b[0m") // reset color

    fmt.Fprint(w, "\x1b[3C") // non-color escape sequence
    fmt.Fprint(w, "3step forward")
    fmt.Fprintln(w)
}

in the case of cmd

in the case of mintty(no windows console)

[johnSchnake]

Sorry for the delay but it looks like this works; I'll let you know if I stumble onto another problem.

[shiena]

OK. This issue was interesting.