用C语言写一个程序自动将一个文件夹里所有CSV文件转换为unicode后另存到另一个文件夹

以下是一个基于C语言实现的自动将一个文件夹里所有CSV文件转换为Unicode编码后另存到另一个文件夹的程序示例。该示例使用了Windows API，所以仅适用于Windows系统。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>
#include <locale.h>

#define BUFFER_SIZE 4096

int main(int argc, char *argv[]) {
    setlocale(LC_ALL, "chs");

    char *input_folder = "input_folder";
    char *output_folder = "output_folder";

    if (!CreateDirectoryA(output_folder, NULL)) {
        DWORD error = GetLastError();

        if (error != ERROR_ALREADY_EXISTS) {
            printf("Failed to create output folder. Error code: %d\n", error);
            return 1;
        }
    }

    char input_pattern[MAX_PATH];
    snprintf(input_pattern, MAX_PATH, "%s\\*.csv", input_folder);

    WIN32_FIND_DATAA find_data;
    HANDLE find_handle = FindFirstFileA(input_pattern, &find_data);

    if (find_handle == INVALID_HANDLE_VALUE) {
        printf("Failed to find input files. Error code: %d\n", GetLastError());
        return 1;
    }

    do {
        if (strcmp(find_data.cFileName, ".") == 0 ||
            strcmp(find_data.cFileName, "..") == 0) {
            continue;
        }

        char input_file[MAX_PATH];
        snprintf(input_file, MAX_PATH, "%s\\%s", input_folder, find_data.cFileName);

        FILE *input_fp = fopen(input_file, "r");

        if (input_fp == NULL) {
            printf("Failed to open input file %s\n", input_file);
            continue;
        }

        char output_file[MAX_PATH];
        snprintf(output_file, MAX_PATH, "%s\\%s", output_folder, find_data.cFileName);

        FILE *output_fp = fopen(output_file, "w");

        if (output_fp == NULL) {
            printf("Failed to open output file %s\n", output_file);
            fclose(input_fp);
            continue;
        }

        char buffer[BUFFER_SIZE];
        size_t read_len;

        while ((read_len = fread(buffer, 1, BUFFER_SIZE, input_fp)) > 0) {
            wchar_t wide_buffer[BUFFER_SIZE];
            int wide_len = MultiByteToWideChar(CP_ACP, 0, buffer, read_len, wide_buffer, BUFFER_SIZE);

            if (wide_len == 0) {
                printf("Failed to convert input buffer to wide string. Error code: %d\n", GetLastError());
                fclose(input_fp);
                fclose(output_fp);
                remove(output_file);
                continue;
            }

            char unicode_buffer[BUFFER_SIZE];
            int unicode_len = WideCharToMultiByte(CP_UTF8, 0, wide_buffer, wide_len, unicode_buffer, BUFFER_SIZE, NULL, NULL);

            if (unicode_len == 0) {
                printf("Failed to convert wide buffer to Unicode string. Error code: %d\n", GetLastError());
                fclose(input_fp);
                fclose(output_fp);
                remove(output_file);
                continue;
            }

            size_t write_len = fwrite(unicode_buffer, 1, unicode_len, output_fp);

            if (write_len != unicode_len) {
                printf("Failed to write output buffer. Error code: %d\n", GetLastError());
                fclose(input_fp);
                fclose(output_fp);
                remove(output_file);
                continue;
            }
        }

        fclose(input_fp);
        fclose(output_fp);
    } while (FindNextFileA(find_handle, &find_data) != 0);

    FindClose(find_handle);

    return 0;
}

这段代码仅供参考，具体实现可能需要根据您的具体需求进行修改。同时，需要注意一些细节问题，例如异常处理、文件路径处理等。