Add color to your prints

Many times, when we are programing in the early phase of the project, the main output that we use for make a debug, is the console, generally error messages that will belong to log file, however all these messages show up with the same default color in terminal. What if we would like print warning and error messages with different colors with the purpose of quickly visual identification or simply facilitate a little the life to own costumers, then you have arrived to correct post.

Are you know that the colors in terminal is simply a character? in fact it is so, in this time i offer the keys for interprets the colors and that you can change the colors like that want.

As well as low level programming languages reserve many #specialCharacters for make operations in machine languages as the variable assignation, sum o subtracts a value or concatenate strings, also exist special characters for text coloring, most new languages use ANSI-C standard because born of C language, include command terminals, operative systems are written with C language.

Most of terminals inherit some commands of C language as `printf` that show in screen the text that we want write.

As we see in the image, printf show a value behind username, different of echo command that show in front username.

As my terminal have apply a theme will produce undesired results, i will change to super user for the changes to take effect.

we will make are print an escape character with printf.

printf '\e[31m' # Imprime el color rojo

reviewing a bit, an escape character is a special symbol that we use for the interpreter or compiler leave out a certain character, generally other symbols as '\' as part of the programming language and include into flat text as \"" \{} \[] \() \n \t and other types of line spaces.

Also exist special characters as '\e' that only is supported in bash terminal, this in turn is summary of \033 character of ANSI-C in octal digit 33 or in turn is \x1b of hexadecimal digit.

Color codes

the next table show the color codes that you can use in terminal, also is possible combine many features separated values by ';' as long as it doesn't contradict.

printf '\e[1;5;7;33;41m' # negrilla;parpadeo;inverso;naranja;bg rojo

Color / Features	Foreground	Background
normal	\e[0m
negrilla	\e[1m
cursiva	\e[3m #no soportado en otras sh
subrayado	\e[4m
parpadeo	\e[5m
reverso	\e[7m
oculto	\e[8m
negro	\e[30m	\e[40m
rojo	\e[31m	\e[41m
verde	\e[32m	\e[42m
naranja	\e[33m	\e[43m
azul	\e[34m	\e[44m
magenta	\e[35m	\e[45m
cyan	\e[36m	\e[46m
gris claro	\e[37m	\e[47m
por defecto	\e[39m	\e[49m
gris oscuro	\e[90m	\e[100m
rosa	\e[91m	\e[101m
verde claro	\e[92m	\e[102m
amarillo	\e[93m	\e[103m
azul claro	\e[94m	\e[104m
purpura claro	\e[95m	\e[105m
cyan o teal	\e[96m	\e[106m
blanco	\e[97m	\e[107m

Also is possible to use these codes in other languages. In #python we can use the escape character '\x1b[<id-color>' for change the color.

This is a short post, but i considered curious and util for share, i hope that this tip is helpful in your projects, See you

Este es un post cortico, pero me pareció curioso y útil para compartir, espero que este truco les sea de ayuda en sus propios proyectos. Nos vemos en un próximo post.