Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Process ANSI escape sequences for Windows console programs.
C Batchfile
Latest commit 6d2a75e @adoxa Merge pull request #86 from amullins83/vs2015_crt_non
Failed to load latest commit information.
.gitignore VC support.
G1.bat Documentation improvements.
G1.txt Documentation improvements.
LICENSE.txt Inject by adding to the Import Directory Table.
ansi.rc Remove ANSI-LLW.exe for good; tweak makefiles & doc; release v1.62.
ansicon.c Recognise more sequences; ignore newline immediately after wrap.
ansicon.h Attributes and saved position are local to each console window.
ansicon.rc Remove ANSI-LLW.exe for good; tweak makefiles & doc; release v1.62.
injdll.c Work with 64-bit AnyCPU; copy original IDT to IAT; log improvements.
makefile.gcc Exclude entire programs; better hooking of dynamically-loaded libraries. Exclude entire programs; better hooking of dynamically-loaded libraries.
procrva.c Work with 64-bit AnyCPU; copy original IDT to IAT; log improvements.
proctype.c Work with 64-bit AnyCPU; copy original IDT to IAT; log improvements. Remove version history & my postal address from
readme.txt Add _CRT_NON_CONFORMING_WCSTOK define
sequences.txt Recognise more sequences; ignore newline immediately after wrap.
util.c Work with 64-bit AnyCPU; copy original IDT to IAT; log improvements.
version.h Add _CRT_NON_CONFORMING_WCSTOK define

ANSICON Latest release

ANSICON provides ANSI escape sequences for Windows console programs. It provides much the same functionality as ANSI.SYS does for MS-DOS.


  • 32-bit: Windows 2000 Professional or later (it won't work with NT or 9X).
  • 64-bit: Vista or later (it won't work with XP64).


Add x86 (if your OS is 32-bit) or x64 (if 64-bit) to your PATH, or copy the relevant files to a directory already in the PATH.

Alternatively, use option -i (or -I, if permitted) to install it permanently, by adding an entry to CMD.EXE's AutoRun registry value (current user or local machine, respectively).


  • Delete ANSI.dll, it has been replaced with ANSI32.dll.
  • Delete ANSI-LLA.exe and ANSI-LLW.exe, they are no longer used.
  • Uninstall a pre-1.50 version and reinstall with this version.


Uninstall simply involves closing any programs that are currently using it; running with -u (and/or -U) to remove it from AutoRun, removing the directory from PATH, and deleting the files. No other changes are made (although you may have created custom environment variables).


Running ANSICON with no arguments will start a new instance of the command processor (the program defined by the ComSpec environment variable, typically CMD.EXE), or display standard input if it is redirected. Any argument will be treated as a program and its arguments.

Options (case-sensitive):

-l  Log to `%TEMP%\ansicon.log`.

-p  Enable the parent process (i.e. the command shell used to run
    ANSICON) to recognise escapes.

-m  Set the current (and default) attribute to grey on black
    (`monochrome`), or the attribute following the `m` (please
    use `COLOR /?` for attribute values).

-e  Echo the command line - a space or tab after the `e` is
    ignored, the remainder is displayed verbatim.

-E  Like `e`, but no newline is added.

-t  Display ("type") each file (or standard input if none or the
    name is `-`) as though they are a single file.

-T  Display `==> FILE NAME <==`, a blank line (or an error
    message), the file and another blank line.

For example, to display file.ans using black on cyan as the default color:

ansicon -m30 -t file.ans

The attribute may start with - to permanently reverse the foreground and background colors (but not when using -p).

For example, to use reversed black on white as the default (i.e. white on black, with foreground sequences changing the background):

ansicon -m-f0 -t file.log

If you experience trouble with certain programs, the log may help in finding the cause; it can be found at %TEMP%\ansicon.log. A number should follow the l:

0   No logging
1   Log process start and end
2   Above, plus log modules used by the process
3   Above, plus log functions that are hooked
4   Log console output (add to any of the above)
8   Append to the existing file (add to any of the above)
16  Log all imported modules (add to any of the above)

The log option will not work with -p; set the environment variable ANSICON_LOG instead. The variable is only read once when a new process is started; changing it won't affect running processes. If you identify a module that causes problems, add it to the ANSICON_EXC environment variable (see ANSICON_API below, but the extension is required).

E.g.: ansicon -l5 will start a new command processor, logging every process it starts along with their output.

Once installed, the ANSICON environment variable will be created. This variable is of the form WxH (wxh), where W & H are the width and height of the buffer and w & h are the width and height of the window. The variable is updated whenever a program reads it directly (i.e. as an individual request, not as part of the entire environment block). For example, set an will not update it, but echo %ansicon% will.

Also created is ANSICON_VER, which contains the version without the point (1.50 becomes 150). This variable does not exist as part of the environment block (set an will not show it).

If installed, GUI programs will not be hooked. Either start the program directly with ansicon, or add it to the ANSICON_GUI variable (see ANSICON_API below).

Using ansicon after install will always start with the default attributes, restoring the originals on exit; all other programs will use the current attributes. The shift state is always reset for a new process.

The Windows API WriteFile and WriteConsoleA functions will set the number of characters written, not the number of bytes. When using a multibyte character set, this results in a smaller number (since multiple bytes are used to represent a single character). Some programs recognise this as a reduced write and will inadvertently repeat previous characters. If you discover such a program, use the ANSICON_API environment variable to record it and override the API, returning the original byte count. Ruby (prior to 1.9.3) is an example of such a program, so use set ANSICON_API=ruby to avoid the repitition. The full syntax is:


PROGRAM is the name of the program, with no path and extension. The leading exclamation inverts the usage, meaning the API will always be overridden, unless the program is in the list. The variable can be made permanent by going to System Properties, selecting the Advanced tab (with Vista onwards, this can be done by running "SystemPropertiesAdvanced") and clicking Environment Variables.


  • The entire console buffer is used, not just the visible window.
  • There's a conflict with NVIDIA's drivers, requiring the setting of the Environment Variable:



Recognized Sequences

The following escape sequences are recognised.

\e]0;titleBEL   Set (xterm) window's title (and icon)
\e[21t          Report (xterm) window's title
\e[s            Save Cursor
\e[u            Restore Cursor
\e[#G           CHA Cursor Character Absolute
\e[#E           CNL Cursor Next Line
\e[#F           CPL Cursor Preceding Line
\e[#D           CUB Cursor Left
\e[#B           CUD Cursor Down
\e[#C           CUF Cursor Right
\e[#;#H         CUP Cursor Position
\e[#A           CUU Cursor Up
\e[#P           DCH Delete Character
\e[?25h         DECTCEM DEC Text Cursor Enable Mode (show cursor)
\e[?25l         DECTCEM DEC Text Cursor Enable Mode (hide cursor)
\e[#M           DL  Delete Line
\e[#n           DSR Device Status Report
\e[#X           ECH Erase Character
\e[#J           ED  Erase In Page
\e[#K           EL  Erase In Line
\e[#`           HPA Character Position Absolute
\e[#j           HPB Character Position Backward
\e[#a           HPR Character Position Forward
\e[#;#f         HVP Character And Line Position
\e[#@           ICH Insert Character
\e[#L           IL  Insert Line
SI              LS0 Locking-shift Zero (see below)
SO              LS1 Locking-shift One
\e[#;#;#m       SGR Select Graphic Rendition
\e[#d           VPA Line Position Absolute
\e[#k           VPB Line Position Backward
\e[#e           VPR Line Position Forward
  • \e represents the escape character (ASCII 27).
  • # represents a decimal number (optional, in most cases defaulting to 1).
  • BEL, SO, and SI are ASCII 7, 14 and 15.
  • Regarding SGR: bold will set the foreground intensity; blink and underline will set the background intensity; conceal uses background as foreground. See sequences.txt for a more complete description.

I make a distinction between \e[m and \e[0;...m. Both will restore the original foreground/background colors (so 0 should be the first parameter); the former will also restore the original bold and underline attributes, whilst the latter will explicitly reset them. The environment variable ANSICON_DEF can be used to change the default colors (same value as -m; setting the variable does not change the current colors).

Ignored Sequences

The following escape sequences are explicitly ignored.

\e(?        Designate G0 character set ('?' is any character).
\e)?        Designate G1 character set ('?' is any character).
\e[?...     Private sequence
\e[>...     Private sequence

The G0 character set is always ASCII; the G1 character set is always the DEC Special Graphics Character Set.

DEC Special Graphics Character Set

This is my interpretation of the set, as shown by

Char    Unicode Code Point & Name
----    -------------------------
_       U+0020  Space (blank)
`       U+2666  Black Diamond Suit
a       U+2592  Medium Shade
b       U+2409  Symbol For Horizontal Tabulation
c       U+240C  Symbol For Form Feed
d       U+240D  Symbol For Carriage Return
e       U+240A  Symbol For Line Feed
f       U+00B0  Degree Sign
g       U+00B1  Plus-Minus Sign
h       U+2424  Symbol For Newline
i       U+240B  Symbol For Vertical Tabulation
j       U+2518  Box Drawings Light Up And Left
k       U+2510  Box Drawings Light Down And Left
l       U+250C  Box Drawings Light Down And Right
m       U+2514  Box Drawings Light Up And Right
n       U+253C  Box Drawings Light Vertical And Horizontal
o       U+00AF  Macron (SCAN 1)
p       U+25AC  Black Rectangle (SCAN 3)
q       U+2500  Box Drawings Light Horizontal (SCAN 5)
r       U+005F  Low Line (SCAN 7)
s       U+005F  Low Line (SCAN 9)
t       U+251C  Box Drawings Light Vertical And Right
u       U+2524  Box Drawings Light Vertical And Left
v       U+2534  Box Drawings Light Up And Horizontal
w       U+252C  Box Drawings Light Down And Horizontal
x       U+2502  Box Drawings Light Vertical
y       U+2264  Less-Than Or Equal To
z       U+2265  Greater-Than Or Equal To
{       U+03C0  Greek Small Letter Pi
|       U+2260  Not Equal To
}       U+00A3  Pound Sign
~       U+00B7  Middle Dot

G1.txt is a Unicode file to view the glyphs "externally". G1.bat is a batch file (using x86\ansicon) to show the glyphs in the console. The characters will appear as they should using Lucida (other than the Symbols), but code page will influence them when using a raster font (but of particular interest, 437 and 850 both show the Box Drawings).


  • Jean-Louis Morel, for his Perl package Win32::Console::ANSI. It provided the basis of ANSI.dll.

  • Sergey Oblomov (hoopoepg), for Console Manager. It provided the basis of ansicon.exe.

  • Anton Bassov's article "Process-wide API spying - an ultimate hack" in "The Code Project".

  • Richard Quadling - his persistence in finding bugs has made ANSICON what it is today.

  • Dmitry Menshikov, Marko Bozikovic and Philippe Villiers, for their assistance in making the 64-bit version a reality.

  • Luis Lavena and the Ruby people for additional improvements.

  • Leigh Hebblethwaite for documentation tweaks.

  • Vincent Fatica for pointing out \e[K was not right.



The original zipfile can be freely distributed, by any means. However, I would like to be informed if it is placed on a CD-ROM (other than an archive compilation; permission is granted, I'd just like to know).

Modified versions may be distributed, provided it is indicated as such in the version text and a source diff is made available.

In particular, the supplied binaries are freely redistributable.

A formal license (zlib) is available in LICENSE.txt.

Copyright 2005-2014 Jason Hood

Something went wrong with that request. Please try again.