I want to know how to output a text on color in the C language.
I heard that some methods work on Windows but not on OS X.
The standard "ANSI" escape sequences for colored text work just fine in Terminal windows on the Mac. For example:
printf("\033[34mblue\033[0m\n");
Related
I'm new to C and I came across this code and it was confusing me:
sprintf(banner1, "\e[37╔═╗\e[37┌─┐\e[37┌┐┌\e[37┌─┐\e[37┌─┐\e[37┌─┐\e[37┌─┐\e[37m\r\n");
sprintf(banner2, "\e[37╠═╝\e[37├─┤\e[37│││\e[37│ ┬\e[37├─┤\e[37├┤\e[37 ├─┤\e[37m\r\n");
sprintf(banner3, "\e[37╩ \e[37┴ ┴┘\e[37└┘\e[37└─┘\e[37┴ ┴\e[37└─┘\e[37┴ ┴\e[37m\r\n");
I was just confused as I don't know what do \e[37 and \r\n mean. And can I change the colors?
This looks like an attempt to use ANSI terminal color escapes and Unicode box drawing characters to write the word "PANGAEA" in a large, stylized, colorful manner. I'm guessing it's part of a retro-style BBS or MUD system, intended to be interacted with over telnet or ssh. It doesn't work, because whoever wrote it made a bunch of mistakes. Here's a corrected, self-contained program:
#include <stdio.h>
int main(void)
{
printf("\e[31m╔═╗\e[32m┌─┐ \e[33m┌┐┌\e[34m┌─┐\e[35m┌─┐\e[36m┌─┐\e[37m┌─┐\e[0m\n");
printf("\e[31m╠═╝\e[32m├─┤ \e[33m│││\e[34m│ ┬\e[35m├─┤\e[36m├┤ \e[37m├─┤\e[0m\n");
printf("\e[31m╩ \e[32m┴ ┴┘\e[33m┘└┘\e[34m└─┘\e[35m┴ ┴\e[36m└─┘\e[37m┴ ┴\e[0m\n");
return 0;
}
The mistakes were: using \r\n instead of plain \n, leaving out the m at the end of each and every escape sequence, and a number of typos in the actual letters (missing spaces and the like).
I deliberately changed sprintf(bannerN, ... to printf to make it a self-contained program instead of a fragment of a larger system, and changed the actual color codes used for each letter to make it a more interesting demo. When I run this program on my computer I get this output:
The program will only work on your computer if your terminal emulator supports both ANSI color escapes and printing UTF-8 with no special ceremony. Most Unix-style operating systems nowadays support both by default; I don't know about Windows.
I searched and tried some solutions, none worked.
ansi escape sequences - only works for unix-based
textcolor() (conio.h and curses.h) - only in turbo c++
graphic.h - doesn't really fix it, you'd have to change your .c files to .cpp every time
Is there a simple, or simple-ish, way to print color in c?
Newer Windows can use the Unix way by enabling Virtual Terminal Sequences in the console.
Older Windows need to use SetConsoleTextAttribute. See https://learn.microsoft.com/en-us/windows/console/console-screen-buffers#character-attributes.
For example, if you want to turn text red, you'd do
#include "Windows.h"
void MakeRed() {
HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
SetConsoleTextAttribute(hConsole, FOREGROUND_RED);
}
I have some code in C to print out lines of text in different colors.
It's working on Linux using escape characters (for example here).
It's working on Windows using SetConsoleTextAttribute
But my problem is when using Cygwin.
Escape characters don't work on Cygwin.
And calls to GetConsoleScreenBufferInfo always failed, and getLastErrorText() gives me this message:
Incorrect function. (0x1).
So my question is: how to print text in color from a C program running in a Cygwin terminal?
Do I need to install special libraries?
Thanks SzG and M Oehm for you comments.
As you said, M Oehm, the linux example is working.
I found the problem in my code. I was using the color value for Windows instead of the ones for Linux.
For example:
_ftprintf(target, TEXT("%c[%d;%dm%s%c[K\n"),
0x1B, foreground, background, printBuffer, 0x1B);
The values for foreground and background were not correct.
Now it's working.
Is this possible?
I know it's possible in the command prompt using COLOR ##
but is it possible in C using bloodshed?
Thanks,
What operating system? What terminal do you have available? Note that this has nothing to do with C, let alone bloodshed. You output a string which the terminal may or may not choose to interpret as a color. You have to see how to do that with your terminal. The solution of course is not portable. One such example for a terminal supporting escape sequences is
printf("\\x1b[1;33mThis is yellow\\x1b[m(Back to default)\n");
You may be interested in ANSI terminal's color escape sequences
You may also want to look for libraries that do that for limited number of terminals. For example, ncurses could help you in Linux.
If you're on *nix, osx, or using cygwin msys on windows, your terminal should support the ANSI sequences Fred Larson mentions (not sure about osx). The normal windows terminal does not. But bloodshed can use cygwin, so you're in luck.
Here's an example:
#include <stdio.h>
#define BOLDMAGENTA "\033[1;35m"
#define BOLDGREEN "\033[1;32m"
int main(void) {
printf("%shello %sworld\n", BOLDMAGENTA, BOLDGREEN);
return 0;
}
Note that this leaves the terminal in bright green, but if your prompt sets colours, that will get reset.
Here's some explanation of ANSI escape codes:
http://en.wikipedia.org/wiki/ANSI_escape_code
Is it possible to color the console output in just plain ANSI C? Without an external library? Can this be done in Windows, Linux, or Mac OS X?
just plain ANSI C?
No. The C standard doesn't assume the stdout is a console or has color.
Can this be done in Windows, Linux, or Mac OS X?
Yes. See How can I print to the console in color on Mac OS X in a cross-platform manner? for Linux and Mac OS X.
For Windows, you may need to directly access the Console Functions if you want to avoid external libraries.
Yes, in Linux/ Mac it is possible using ANSI C89.
You can either manipulate the font and the color of the text.
using the following command:
printf("%c[0;00mHello, world!\n", 27); /* White color */
printf("%c[1;33mHello, world!\n", 27); /* Yellowish color */
printf("%c[1;34mHello, world!\n", 27); /* Blueish color */
Notice that the left part of the ";" (where the numbers 0, 1 are) manipulates the text font,
the right part of ";" manipulates the colors. You can experiment on your own and find out new colors.
This code compiles using "-ansi -pedantic" command with no warnings nor errors.
***** Edit *****
In Windows based systems you can achieve colorful console text/background of text using the following example:
#include <stdio.h>
#include <windows.h>
int main(void)
{
/* Point to our console */
HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
int i = 0;
/* Iterate through colors */
for(; i < 255; i++)
{ /* i stands for color type: could refer to actual text color or background color of text */
SetConsoleTextAttribute(hConsole, i);
printf("Colorful text");
}
getchar();
return 0;
}
Good luck!
in Linux this can be done, if you you know the shell-specific control codes / Escape sequences.
Linux/OSX/Unix
On posix systems you can use the ANSI escape sequences.
Windows
On windows it is a bit more complicated, there are multiple solutions:
Win32 API
Using the Win32 API to set the output color before printing to the console using SetConsoleTextAttribute and friends. This is a lot more cumbersome than simply embedding ANSI escape sequences in your strings, and requires you to handle Windows as a special case.
Windows ANSI.SYS and Replacement
Older version of windows contained ANSI.SYS, but this has been removed in later versions. ANSICON is a replacement for this that you can install to get ANSI color code support in the windows command prompt: https://github.com/adoxa/ansicon
Embeddable no external dependencies solution
Here is a project that can be easily integrated into any existing project without relying on ANSI.SYS or ANSICON being installed.
It takes a string containing ANSI escape sequences and translates them to the relevant Win32 equivalent API functions: https://github.com/mattn/ansicolor-w32.c
It is true that ISO C knows nothing about the console being capable of displaying colors, however there is an ANSI norm for console capabilities management, based on escape character controls. This works transparently in Linux and Mac OS X, however it fails in Windows, in which you need to use the primitives of the Win32 API.
You can find below a very simple library that allows to clear the screen, show colors and locate the cursor in a specific coordinate, in a multiplatform way (Win32 & Unix-like systems).
It comes with plain C source files (.c and .h), doxygen documentation in Spanish (doc/), and a simple demo (main.c)
http://github.com/Baltasarq/cscrutil/