A simple header file with various Linux-compatible C text formatting macros. The provided macros are:

• fg(color, string): Renders the text with the given foreground color.
• bg(color, string): Renders the text with the given background color.
• fg_b(color, string): Same as fg(), but uses bright versions of default colors.
• bg_b(color, string): Same as bg(), but uses bright versions of default colors.
• bold(string): Renders the string in bold.
• underline(string): Renders the string underlined.
• reverse_video(string): Renders the string, with the foreground and background colors swapped.

See the provided test file (test.c) for precise examples of usage.

txtfmt.h provides eight standard colors to work with, each of which is denoted using a lowercase word: black, red, green, brown, blue, magenta, cyan, and white. Because of the way the macros are set up, these special symbols can only be used in the color argument to fg, bg, fg_b, and bg_b; they will not conflict with other variable or function names.

Since the formatting functions are implemented as macros, they throw compiler errors when operating on non-constant strings. So, for example, the following code won't work:

const char *foo = "abcd";
puts(fg(green, foo));

Instead, you should use printf or sprintf to substitute the text into a format string appropriately. The previous example thus becomes:

const char *foo = "abcd";
printf(fg(green, "%s"), foo);