Making some text in printf appear in green and red

Question

Hello,

linux gcc 4.4.1

I have the following fprintf statement and I would like to have the OK as green and the FAILED as red. Is this possible?

if(devh == -1)
{
    fprintf(stderr, "Device [ FAILED ]\n");
}
else
{
    fprintf(stderr, "Device [ OK ]\n");
}

Many thanks for any suggestions,

Answer 1

You should probably use some library such as ncurses to handle terminal.

Alternatively, under Linux you could use some console escape sequences such as:

printf ("\033[32;1m OK \033[0m\n");

(in this case 32 stands for green), but it is neither portable nor elegant.

Answer 2

I use to use the following macros to add color to terminal output.

#define RESET   "\033[0m"
#define BLACK   "\033[30m"      /* Black */
#define RED     "\033[31m"      /* Red */
#define GREEN   "\033[32m"      /* Green */
#define YELLOW  "\033[33m"      /* Yellow */
#define BLUE    "\033[34m"      /* Blue */
#define MAGENTA "\033[35m"      /* Magenta */
#define CYAN    "\033[36m"      /* Cyan */
#define WHITE   "\033[37m"      /* White */
#define BOLDBLACK   "\033[1m\033[30m"      /* Bold Black */
#define BOLDRED     "\033[1m\033[31m"      /* Bold Red */
#define BOLDGREEN   "\033[1m\033[32m"      /* Bold Green */
#define BOLDYELLOW  "\033[1m\033[33m"      /* Bold Yellow */
#define BOLDBLUE    "\033[1m\033[34m"      /* Bold Blue */
#define BOLDMAGENTA "\033[1m\033[35m"      /* Bold Magenta */
#define BOLDCYAN    "\033[1m\033[36m"      /* Bold Cyan */
#define BOLDWHITE   "\033[1m\033[37m"      /* Bold White */

...and use like

printf( GREEN "Here is some text\n" RESET );

Example of use http://stackoverflow.com/questions/138383/colored-grep/138528#138528

And for your example

if(devh == -1)
{
    fprintf(stderr, "Device [ " RED "FAILED" RESET " ]\n");
}
else
{
    fprintf(stderr, "Device [ " GREEN "OK" RESET " ]\n");
}