C语言把文件读入字符串以及将字符串写入文件-蒲公英云

C语言把文件读入字符串以及将字符串写入文件

1.纯C实现

FILE *fp;
    if ((fp = fopen("example.txt", "rb")) == NULL)
    { 
        exit(0);
    }
    fseek(fp, 0, SEEK_END);
    int fileLen = ftell(fp);
    char *tmp = (char *) malloc(sizeof(char) * fileLen);
    fseek(fp, 0, SEEK_SET);
    fread(tmp, fileLen, sizeof(char), fp);
    fclose(fp);
    for(int i = 0; i < fileLen; ++i)
    { 
        printf("%d ", tmp[i]);
    }
    printf("\n");
    if ((fp = fopen("example.txt", "wb")) == NULL)
    { 
        exit(0);
    }
    rewind(fp);
    fwrite(tmp, fileLen, sizeof(char), fp);
    fclose(fp);
    free(tmp);

2.利用CFile（MFC基类）

CFile需要包含的头文件为Afx.h

打开文件的函数原型如下

if(!(fp.Open((LPCTSTR)m_strsendFilePathName,CFile::modeRead)))

有多种模式,常用的有如下:

modeRead
modeWrite
modeReadWrite
modeCreate

文件类型有两种:

typeBinary
typeText

读写非文本文件一定要用typeBinary

读取数据的函数原型:

virtual UINTRead(void*lpbuf, UINT nCount);

将文件读出:

CFile fp;
if(!(fp.Open((LPCTSTR)m_strsendFilePathName,CFile::modeRead)))
{ 
    return;
}
fp.SeekToEnd();
unsignedint fpLength = fp.GetLength();
char *tmp= new char[fpLength];
fp.SeekToBegin();    //这一句必不可少
if(fp.Read(tmp,fpLength) < 1)
{ 
    fp.Close();
    return;
}
// 新建文件并写入
if(!(fp.Open((LPCTSTR)m_strsendFilePathName, CFile::modeCreate | CFile::modeWrite |CFile::typeBinary)))
{ 
    return;
}
fp.SeekToBegin();
fp.write(tmp,fpLength);
fp.close;