echo.c

// The MIT License (MIT)

// Copyright (c) 2022 Harrison Ho

//  Permission is hereby granted, free of charge, to any person obtaining a
//  copy of this software and associated documentation files (the "Software"),
//  to deal in the Software without restriction, including without limitation
//  the rights to use, copy, modify, merge, publish, distribute, sublicense,
//  and/or sell copies of the Software, and to permit persons to whom the
//  Software is furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
//  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
//  DEALINGS IN THE SOFTWARE.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>

#include "./utils/slice.h"

// UNIX  echo

#define DEFAULT_POOL_SIZE 1024 // 1KB

int main(int argc, char const *argv[])
{

    slice_t *slice = make_slice(0, DEFAULT_POOL_SIZE);
    int used_index = 0;

    for (int i = 1; i < argc; i++)
    {
        size_t arg_len = (size_t)(strlen(argv[i]) + 1);
        // last element of slice
        // append null terminator
        if (i == argc - 1)
        {
            slice_grow(slice, arg_len);
            // copy included null terminator
            memcpy((void *)(slice->pool + used_index), (void *)argv[i], arg_len + 1);
        }

        if (arg_len > slice->cap)
        {
            // grow before append
            slice_grow(slice, arg_len);
        }

        // copy argv[i] to slice
        memcpy((void *)(slice->pool + used_index), (void *)argv[i], arg_len);
        // replace the last space with a space
        slice->pool[used_index - 1] = ' ';
        used_index += arg_len;
    }
    // format output slice
    printf("%s\n", slice->pool);

    // clean up
    free(slice->pool);

    return 0;
}