To use, first compile ASyncIO.c using:

sc NMINC STRMERGE NOSTKCHK IGNORE=73 ASyncIO.c

which produces the ASyncIO.o file, and then compile this example by linking to it:

sc LINK example.c LIB asyncio.o

By default, the code copies the s:user-startup file to ram:tmp_file.

copyasync.c

/*************************************************************************/
/*    Copyright (C) 2015 Wizardry and Steamworks - License: GNU GPLv3    */
/*************************************************************************/
/*                                                                       */
/*  copyasync                                                            */
/*                                                                       */
/*  Copies a file to RAM:                                                 */
/*                                                                       */
/*  Depends on: ASyncIO.o, ASyncIO.h                                     */
/*  Compile using SASC: sc LINK example.c LIB asyncio.o                  */
/*                                                                       */
/*************************************************************************/
 
#include <exec/types.h>
#include <exec/exec.h>
#include <dos/dos.h>
#include <dos/dosextens.h>
#include <stdio.h>
 
#include <clib/exec_protos.h>
#include <clib/dos_protos.h>
 
#include "ASyncIO.h"
 
#define SOURCE "s:user-startup"
#define DESTINATION "ram:tmp_file"
 
int main(void) {
    struct AsyncFile *i;
    struct AsyncFile *o;
 
    LONG c;
 
    /* Open the source file asynchronousely. */
    if(!(i = OpenAsync(SOURCE, MODE_READ, 8192))) {
        printf("error: unable to open file.\n");
        return 1;
    }
 
    /* Open the destination file asynchronousely. */
    if(!(o = OpenAsync(DESTINATION, MODE_WRITE, 8192))) {
        printf("error: unable to open destination file.\n");
        return 1;
    }
 
    /* While there is a new character in the input
     * write the character to the output */
    while((c = ReadCharAsync(i)) >= 0) {
        WriteCharAsync(o, c);
    }
 
    /* Close handles. */
    CloseAsync(o);
    CloseAsync(i);
 
    return 0;
}