varch/doc/arg.en.md

Introduction

The arg module is primarily designed for scenarios that involve variable numbers of arguments, allowing you to retrieve the count of those arguments and access specific positional arguments.

Interface

Functions

#define ARG_MAX             // Maximum number of supported variable arguments
#define ARGC(...)           // Current number of variable arguments, does not support distinguishing empty arguments
#define ARGC0(...)          // Current number of variable arguments, supports distinguishing empty arguments but requires more compile-time space; use as needed
#define ARGS(x, ...)        // Retrieve the argument at a specified position

In usage, you only need to focus on the macro definitions above; the rest can be ignored.

Example usage:

static void test(void)
{
    printf("ARG_MAX %d\r\n", ARG_MAX);

    printf("ARGC %d\r\n", ARGC());
    printf("ARGC %d\r\n", ARGC(A));
    printf("ARGC %d\r\n", ARGC(A, B));
    printf("ARGC %d\r\n", ARGC(A, B, C));

    printf("ARGC %d\r\n", ARGC0());
    printf("ARGC %d\r\n", ARGC0(A));
    printf("ARGC %d\r\n", ARGC0(A, B));
    printf("ARGC %d\r\n", ARGC0(A, B, C));

    printf("ARGS %s\r\n", ARGS(0, "arg0", "arg1", "arg2"));
    printf("ARGS %s\r\n", ARGS(1, "arg0", "arg1", "arg2"));
    printf("ARGS %s\r\n", ARGS(2, "arg0", "arg1", "arg2"));
}

Results:

ARG_MAX 124
ARGC 1
ARGC 1
ARGC 2
ARGC 3
ARGC 0
ARGC 1
ARGC 2
ARGC 3
ARGS arg0
ARGS arg1
ARGS arg2