69,374
社区成员
发帖
与我相关
我的任务
分享
/* fread example: read a complete file 读取一个完整的文件 */
#include <stdio.h>
#include <stdlib.h>
int main()
{
FILE* pFile; //文件指针
long lSize; // 用于文件长度
char* buffer; // 文件缓冲区指针
size_t result; // 返回值是读取的内容数量
pFile = fopen("myfile.bin" , "rb");
if (pFile == NULL) {fputs("File error", stderr); exit(1);} // 如果文件错误,退出1
// obtain file size: 获得文件大小
fseek(pFile , 0 , SEEK_END); // 指针移到文件末位
lSize = ftell(pFile); // 获得文件长度
rewind(pFile); // 函数rewind()把文件指针移到由stream(流)指定的开始处, 同时清除和流相关的错误和EOF标记
// allocate memory to contain the whole file: 为整个文件分配内存缓冲区
buffer = (char*) malloc(sizeof(char) * lSize); // 分配缓冲区,按前面的 lSize
if (buffer == NULL) {fputs("Memory error", stderr); exit(2);} // 内存分配错误,退出2
// copy the file into the buffer: 该文件复制到缓冲区
result = fread(buffer, 1, lSize, pFile); // 返回值是读取的内容数量
if (result != lSize) {fputs("Reading error", stderr); exit(3);} // 返回值如果不和文件大小,读错误
/* the whole file is now loaded in the memory buffer. */ //现在整个文件载入内存缓冲区
// 读到内存,看自己怎么使用了...............
// ...........
// terminate // 文件终止错误
fclose(pFile);
free(buffer);
return 0;
}
/* fread example: read a complete file */
#include <stdio.h>
#include <stdlib.h>
int main()
{
FILE* pFile;
long lSize;
char* buffer;
size_t result;
pFile = fopen("myfile.bin" , "rb");
if (pFile == NULL) {fputs("File error", stderr); exit(1);}
// obtain file size:
fseek(pFile , 0 , SEEK_END);
lSize = ftell(pFile);
rewind(pFile);
// allocate memory to contain the whole file:
buffer = (char*) malloc(sizeof(char) * lSize);
if (buffer == NULL) {fputs("Memory error", stderr); exit(2);}
// copy the file into the buffer:
result = fread(buffer, 1, lSize, pFile);
if (result != lSize) {fputs("Reading error", stderr); exit(3);}
/* the whole file is now loaded in the memory buffer. */
// terminate
fclose(pFile);
free(buffer);
return 0;
}
#include <stdio.h>
int main()
{
FILE* pFile;
float buffer[] = { 2.0 , 3.0 , 8.0 };
pFile = fopen("myfile.bin" , "wb");
fwrite(buffer , 1 , sizeof(buffer) , pFile);
fclose(pFile);
float read[3];
pFile = fopen("myfile.bin" , "rb");
fread(read , 1 , sizeof(buffer) , pFile);
printf("%f\t%f\t%f\n", read[0], read[2], read[3]);
return 0;
}
/* fwrite example : write buffer */
#include <stdio.h>
int main ()
{
FILE * pFile;
char buffer[] = { 'x' , 'y' , 'z' };
pFile = fopen ( "myfile.bin" , "wb" );
fwrite (buffer , 1 , sizeof(buffer) , pFile );
fclose (pFile);
return 0;
}