stdlib and colored output in C

Solution 1:

All modern terminal emulators use ANSI escape codes to show colours and other things.
Don't bother with libraries, the code is really simple.

More info is here.

Example in C:

#include <stdio.h>

#define ANSI_COLOR_RED     "\x1b[31m"
#define ANSI_COLOR_GREEN   "\x1b[32m"
#define ANSI_COLOR_YELLOW  "\x1b[33m"
#define ANSI_COLOR_BLUE    "\x1b[34m"
#define ANSI_COLOR_MAGENTA "\x1b[35m"
#define ANSI_COLOR_CYAN    "\x1b[36m"
#define ANSI_COLOR_RESET   "\x1b[0m"

int main (int argc, char const *argv[]) {

  printf(ANSI_COLOR_RED     "This text is RED!"     ANSI_COLOR_RESET "\n");
  printf(ANSI_COLOR_GREEN   "This text is GREEN!"   ANSI_COLOR_RESET "\n");
  printf(ANSI_COLOR_YELLOW  "This text is YELLOW!"  ANSI_COLOR_RESET "\n");
  printf(ANSI_COLOR_BLUE    "This text is BLUE!"    ANSI_COLOR_RESET "\n");
  printf(ANSI_COLOR_MAGENTA "This text is MAGENTA!" ANSI_COLOR_RESET "\n");
  printf(ANSI_COLOR_CYAN    "This text is CYAN!"    ANSI_COLOR_RESET "\n");

  return 0;
}

Solution 2:

Dealing with colour sequences can get messy and different systems might use different Colour Sequence Indicators.

I would suggest you try using ncurses. Other than colour, ncurses can do many other neat things with console UI.

Solution 3:

You can output special color control codes to get colored terminal output, here's a good resource on how to print colors.

For example:

printf("\033[22;34mHello, world!\033[0m");  // shows a blue hello world

EDIT: My original one used prompt color codes, which doesn't work :( This one does (I tested it).

Solution 4:

You can assign one color to every functionality to make it more useful.

#define Color_Red "\33[0:31m\\]" // Color Start
#define Color_end "\33[0m\\]" // To flush out prev settings
#define LOG_RED(X) printf("%s %s %s",Color_Red,X,Color_end)

foo()
{
LOG_RED("This is in Red Color");
}

Like wise you can select different color codes and make this more generic.

Solution 5:

#include <stdio.h>

#define BLUE(string) "\x1b[34m" string "\x1b[0m"
#define RED(string) "\x1b[31m" string "\x1b[0m"

int main(void)
{
    printf("this is " RED("red") "!\n");

    // a somewhat more complex ...
    printf("this is " BLUE("%s") "!\n","blue");

    return 0;
}

reading Wikipedia:

  • \x1b[0m resets all attributes
  • \x1b[31m sets foreground color to red
  • \x1b[44m would set the background to blue.
  • both : \x1b[31;44m
  • both but inversed : \x1b[31;44;7m
  • remember to reset afterwards \x1b[0m ...