CODEWITHSUNDEEP
c++ccolorsansi-escape
goldenmean
goldenmean

Reputation: 19026

How can I use ANSI Escape Codes for outputting colored text in C and C++?

I read about ANSI-C escape codes here. Tried to use it in C/C++ printf/std::cout to colorize the text outputted to console, but without success.

My attempt:

#include <iostream>
#include <cstdio>

int main() {
    int a=3, b=5;
    int &ref = a;
    ref = b;
    
    //cout << "\155\32\m" << a << b <<'\n'; //here it prints m→m 5, no colored text
    printf("\155\32\m %d",a); //here to it prints same - m→m 5, 

    getchar();
}

How can I use these escape codes to output colored text to console?

Am I missing something?

Also, I remember that in some C++ code I saw a call to this function

textcolor(10);

But it gives compilation errors in g++ and in Visual Studio. Which compiler had this function available? Any details?

Upvotes: 13

Views: 59734

Answers (10)

starball
starball

Reputation: 52167

Colorization ANSI escape codes use Select Graphic Rendition (SGR) sequences, which are of the form CSI n m, where a CSI (which stands for Control Sequence Introducer) sequence is just the escape character followed by an opening square brace, n is some parameter, and m is the literal "m" character.

The tricky part is really just getting the escape character in a C++ string literal. You can see https://en.cppreference.com/w/cpp/language/escape for info about string escapes in C++. The TL;DR is that you can use octal form like \nnn, or hexadecimal form like \xn.... The ESC character in ASCII is value 27, which in octal is 33, and in hexadecimal, is 1b. So you can either use "\033[...m" or "\x1b[...m".

For example:

"\033[31mred \033[33myellow \033[32mgreen \033[36mcyan \033[34mblue \033[35mmagenta"
"\x1b[31mred \x1b[33myellow \x1b[32mgreen \x1b[36mcyan \x1b[34mblue \x1b[35mmagenta"

(fun fact: Bash uses similar escape sequences for strings, so you can echo -e the above string literals in a Bash shell and it will also work)

For C++20, I use the following snippet in a header file in one of my projects to define some more readable constants:

#include <string_view>

struct SgrPair final {
    std::string_view on;
    std::string_view off;
};
#if USE_ANSI_ESC
#define SGR(NAME, ON_STR, OFF_STR) inline constexpr SgrPair NAME { .on {(ON_STR)}, .off {(OFF_STR)} };
#else
#define SGR(NAME, ON_STR, OFF_STR) inline constexpr SgrPair NAME { .on {""}, .off {""} };
#endif

SGR(dim, "\033[2m",  "\033[22m")
SGR(red, "\033[31m", "\033[39m")

#undef SGR

In the above snippet, the user doing the compilation can choose whether or not to define the USE_ANSI_ESC macro to a truthy value.

See also List of ANSI color escape sequences and https://www.ecma-international.org/publications-and-standards/standards/ecma-48/.

Windows pain and suffering fun

If your program is printed to a Windows console like cmd, you need to write something in your program to enable ANSI escape codes in that console (see https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences):

#ifdef _WIN32
#include <windows.h>
#endif

int main() {
    // ...
    #ifdef _WIN32
    DWORD con_mode;
    GetConsoleMode(GetStdHandle(STD_OUTPUT_HANDLE), &con_mode);
    con_mode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    SetConsoleMode(GetStdHandle(STD_OUTPUT_HANDLE), con_mode);
    // ...
}

The other answers already touched on this, but I added some preprocessor wrapping to make it easier to compile on non-Windows platforms without changing the code.

What "textcolor" is

It's a Turbo C/C++ Compiler function. See page 384 of the Turbo C/C++ Compiler 2.0 docs. See also: conio.h doesn't contain textcolor()?.

Upvotes: 0

Cleverhans
Cleverhans

Reputation: 17

I had this problem a while ago, too, using GCC on Windows 10. I had to set the following registry key to get it to work. [HKEY_CURRENT_USER\Console] "VirtualTerminalLevel"=dword:00000001

Upvotes: -1

user2019716
user2019716

Reputation: 643

under windows 10 one can use VT100 style by activating the VT100 mode in the current console :

#include <windows.h>
#include <iostream>

#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
#define DISABLE_NEWLINE_AUTO_RETURN  0x0008

int main()
{       
   HANDLE handleOut = GetStdHandle(STD_OUTPUT_HANDLE);
   DWORD consoleMode;
   GetConsoleMode( handleOut , &consoleMode);
   consoleMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
   consoleMode |= DISABLE_NEWLINE_AUTO_RETURN;            
   SetConsoleMode( handleOut , consoleMode );

   for (int i = 0; i < 10; ++i)
   {
      std::cout << "\x1b[38;2;" << 5 * i << ";" << 255 - 10 * i << ";220m" 
             << "ANSI Escape Sequence " << i << std::endl;
   }
}

see msdn page : [https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences][1]

Upvotes: 6

Foxie Flakey
Foxie Flakey

Reputation: 420

This will work in any OS that support ANSI escape sequence

#include <iostream>
    
void printColored(char r, char g, char b, char _char_) {
  std::cout << '\33' << '[' << '38' << ';' << '2' << ';' << r << ';' << g << ';' << b << 'm' << _char_ << '\33' << '[' << 'm'
}

Note:

char r is your red in RGB

char g is your green in RGB

char b is your blue in RGB

char char is you character to print in colored text

This may be been answered about using ANSI Escape to output RGB colored text at ANSI Color Specific RGB Sequence Bash

If you think that not true just edit it then i will accept the modification

Upvotes: 0

Shades
Shades

Reputation: 673

A note to anybody reading this post: https://en.wikipedia.org/wiki/ANSI_escape_code#DOS_and_Windows

In 2016, Microsoft released the Windows 10 Version 1511 update which unexpectedly implemented support for ANSI escape sequences. The change was designed to complement the Windows Subsystem for Linux, adding to the Windows Console Host used by Command Prompt support for character escape codes used by terminal-based software for Unix-like systems. This is not the default behavior and must be enabled programmatically with the Win32 API via SetConsoleMode(handle, ENABLE_VIRTUAL_TERMINAL_PROCESSING)

Upvotes: 5

stansy
stansy

Reputation: 318

Windows 10 supports ANSI Escape Sequences on the VT100 and derived terminal emulator technologies with 256 color extension. Description and examples are on the page Console Virtual Terminal Sequences.

std::ostringstream ss;
for (int i = 0; i < 10; ++i)
    ss << "\x1b[38;2;" << 5 * i << ";" << 255 - 10 * i << ";220m" 
        << "ANSI Escape Sequence " << i << std::endl;   
std::cout << ss.str();

Upvotes: 2

Baltasarq
Baltasarq

Reputation: 12232

I created a very simple text-management library some time ago, being multiplatform, it uses native API calls for Windows and ANSI escape sequences for the rest of the platforms. It is fully documented and you can also browse the source code.

About your specific question, I think you are missing some codes. For example, in order to change the color of text, you should use something like:

static const char * CSI = "\33[";
printf( "%s%s", CSI, "31m" );   // RED

Hope this helps.

Upvotes: 8

pau.estalella
pau.estalella

Reputation: 2243

I'm afraid you forgot the ESC character:

#include <cstdio>

int main()
{
    printf("%c[%dmHELLO!\n", 0x1B, 32);
}

Unfortunately it will only work on consoles that support ANSI escape sequences (like a linux console using bash, or old Windows consoles that used ansi.sys)

Upvotes: 14

Cubic
Cubic

Reputation: 15703

ANSI formatting codes aren't supported in windows.

http://en.wikipedia.org/wiki/ANSI_escape_code

Upvotes: 1

user707582
user707582

Reputation:

ANSI escape codes worked on DOS using the ansi.sys device driver. They won't work windows xp or higher. You need to use the console API SetConsoleTextAttribute()

textcolor was available in the borland turbo c++ compiler.

Upvotes: 3

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