kyaa

super hacky macro hacks for parsing arguments in C.

prerequisites

C99 or greater.

standard library headers:

stdbool.h
stdio.h
string.h

tutorial

ensure argc and argv are defined. kyaa doesn't actually care if it's in main or not.

iterate over the arguments with KYAA_LOOP:

int main(int argc, char *argv[]) {
    KYAA_LOOP {
        // KYAA_ITER, kyaa_name, kyaa_read_stdin, and kyaa_flag are exposed here.
        // [other code goes here]
    }
    return 0;
}

use KYAA_BEGIN and KYAA_END to begin parsing arguments. put unrelated code above KYAA_BEGIN or below KYAA_END, but not within:

    KYAA_LOOP {
        // [other code goes here]
        KYAA_BEGIN
        // kyaa_arg and kyaa_etc are exposed here.
        // [kyaa code goes here]
        KYAA_END
        // [other code goes here]
    }

use KYAA_FLAG for defining flags that don't take an argument, and KYAA_FLAG_ARG or KYAA_FLAG_LONG for flags that do:

    bool use_feature = false;
    char *log_fn = "logs.txt";
    long my_var = 0;
    KYAA_LOOP {
        // [other code goes here]
        KYAA_BEGIN

        // arguments: short flag, long flag, help description
        KYAA_FLAG("-x", "--enable-feature",
"        enable some feature")
            use_feature = true;

        // same arguments, but kyaa_etc contains the relevant string.
        KYAA_FLAG_ARG("-l", "--log-file",
"        use a given filename for the log file")
            log_fn = kyaa_etc;

        // same arguments, kyaa_etc is set, but kyaa_flag_arg is also set.
        KYAA_FLAG_LONG("-v", "--var",
"        set an integer variable\n"
"        default: 0")
            my_var = kyaa_flag_arg;

        KYAA_END
        // [other code goes here]
    }

kyaa secretly wraps flag handling in if/else statements with {} blocks. do not confuse it for a switch/case method.

kyaa handles -h and --help for printing help text. additional help text may be defined using KYAA_HELP:

    KYAA_LOOP {
        KYAA_BEGIN
        KYAA_HELP(
"  {files...}\n"
"        do things with files.")
        KYAA_END

        do_stuff(kyaa_arg);
    }

kyaa interprets an argument of - as a request to enable reading from stdin: kyaa_read_stdin is set to true.

arguments may be passed in three ways, consider:

-v42
-v 42
--var 42

kyaa returns KYAA_OKAY when -h or --help is given, and KYAA_ERROR in the event of invalid flags, missing arguments, or invalid numbers (KYAA_FLAG_LONG). kyaa uses continue for handling arguments.

kyaa prints error messages to stderr, and help text to stdout.

KYAA_ITER may be redefined to avoid name collisions.

TODO

support --var=42 argument style
fix overlapping names, e.g. KYAA_FLAG vs kyaa_flag, KYAA_FLAG_ARG vs kyaa_flag_arg, etc.
maybe pass argc/argv manually?

API

kyaa.h

KYAA_OKAY       DEFINE int
KYAA_ERROR      DEFINE int
KYAA_ITER       DEFINE int
KYAA_SETUP      MACRO
KYAA_LOOP       MACRO
KYAA_BEGIN      MACRO
KYAA_END        MACRO
KYAA_DESCRIBE   MACRO
KYAA_FLAG       MACRO
KYAA_FLAG_ARG   MACRO
KYAA_HELP       MACRO

kyaa_name           char *
kyaa_read_stdin     bool
kyaa_flag           char
kyaa_keep_parsing   bool
kyaa_parse_next     bool
kyaa_arg            char *
kyaa_no_more        bool
kyaa_helping        bool
kyaa_any            bool
kyaa_flag_arg       char *

kyaa_extra.h

KYAA_FLAG_LONG  MACRO

char        *kyaa_skip_spaces(char *str)
const char  *kyaa_str_to_long(char *str, long *p_out)

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