C语言文件读写Demo

CIODemo.c

#include <stdio.h>
#include <time.h>
#define INPUT_BUFFER_SIZE 100 * 1024
int main()
{
    printf("Enter an input file name: ");
    char filename[];
    gets(filename);
    FILE *inputFile = fopen(filename, "rb");
    if (inputFile)
    {
        printf("Enter an output file name: ");
        gets(filename);
        FILE *outputFile = fopen(filename, "wb");
        if (outputFile)
        {
            printf("Copying file...\n");
            time_t startTime = time(NULL);
            char buffer[INPUT_BUFFER_SIZE];
            while (!feof(inputFile))
            {
                size_t numberOfObjects = fread(buffer, sizeof(char), INPUT_BUFFER_SIZE, inputFile);
                fwrite(buffer, sizeof(char), numberOfObjects, outputFile);
            }
            time_t endTime = time(NULL);
            printf("File copied, elapsed time: %u seconds\n", endTime - startTime);
            fclose(inputFile);
            fclose(outputFile);
        }
        else
            printf("Cannot open file: %s", filename);
    }
    else
        printf("Cannot open file: %s", filename);
    return ;
}

以上为读写二进制文件的示例，若要读写文本文件，只需将文件访问模式更改为r（读）和w（写）即可