Linux操作系统下，通过系统调用和库函数分别实现对文件的拷贝

通过系统调用实现 file.copy #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include <string.h> int main(int argc, char *argv[]) { if (argc != 3) { printf("usage : ./copy filename1 filename2\n"); } char buffer[1024] = {0}; int fd1 = open(argv[1], O_RDWR);/*读写方式打开文件1*/ if (-1 == fd1) /*出错判断*/ { perror("open1"); return 1; } int fd2 = open(argv[2], O_RDWR | O_CREAT, S_IRWXU);/*创建新文件并以读写方式打开*/ if (-1 == fd2) { perror("open2"); return 2; } int count = 0; while (count = read(fd1, buffer, 1024)) { if (-1 == count) { perror("read1"); close(fd1); close(fd2); return 3; } int coun2 = write(fd2, buffer, count); if (-1 == count) { perror("write1"); close(fd1); close(fd2); return 4; } memset(buffer, 0, 1024); /*清空数组*/ } close(fd1); close(fd2); return 0; } 通过库函数实现 file.copy #include <stdio.h> #include <string.h> int main(int argc, char *argv[]) { if (argc != 3) { printf("usage : ./copy filename1 filename2\n"); } char buffer[1024] = {0}; FILE *file1 = fopen(argv[1], "r+"); if (NULL == file1) { perror("fopen"); return 1; } FILE *file2 = fopen(argv[2], "w+"); if (NULL == file2) { perror("fopen"); return 2; } int count = 0; count = fread(buffer, sizeof(char), 1024, file1); if(0 == count) /*出错判断*/ { perror("fread"); fclose(file1); fclose(file2); return 3; } fseek(file1, 0, SEEK_SET); /*从头再进行读写*/ while (count = fread(buffer, sizeof(char), 1024, file1)) { int count2 = fwrite(buffer, sizeof(char), count, file2); if (count2 == 0) { perror("fwrite"); fclose(file2); fclose(file1); return 4; } memset(buffer, 0, 1024); } fclose(file1); fclose(file2); return 0; }