iphone开发 C语言读写文件

关键是路径，其他文件操作和windows下一样

 

//这个函数得到存取的路径，读写文件获取路径比较保持一致，比如都用下面函数。
- (char*)GetFilePathByfileName:(char*)filename

{   
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);   
    NSString *documentsDirectory = [paths objectAtIndex:0];   
    NSString *strName = [NSString stringWithFormat:@"%s",filename];
   
    NSString *writablePath = [documentsDirectory stringByAppendingPathComponent:strName];
   
    int len = [writablePath length];
   
    char *filepath = (char*)malloc(sizeof(char) * (len + 1));
   
    [writablePath getCString:filepath maxLength:len + 1 encoding:[NSString defaultCStringEncoding]];   
   
    return filepath;   
}

//保存文件

- (BOOL)SaveFile:(char*)filename data:(char*)data len:(int)len
{   
    char *path = [self GetFilePathByfileName:filename];  
       
    FILE *fp = fopen(path,"wb");  
    if (fp==NULL)
    {
        return false;
    }
    int wlen = fwrite(data, 1, len, fp);
    if (wlen!=len)
    {
        fclose(fp);   
        free(path);
        return false;
    }
    fclose(fp);   
    free(path); 
    return true;   
   
}

//读文件

- (BOOL)ReadFile:(char*)filename data:(char*)data len:(int*)len
{    
   
    char *filepath = [self GetFilePathByfileName:filename];     
     
    FILE *fp = fopen(filepath,"rb");
    if (fp == NULL)
    {
        free(filepath);
        return false;
    }
   
    fseek(fp, 0, SEEK_END);
    int filelen = ftell(fp);
    fseek(fp, 0, SEEK_SET);
   
    if (*len < filelen)
    {
        fclose(fp);       
        free(filepath);
        return false;
    }
   
    int rlen = fread(data, 1, filelen, fp);
   
    if (rlen < filelen)
    {
        fclose(fp);       
        free(filepath);
        return false;
    }
   
    *len = filelen;   
    fclose(fp);       
    free(filepath);
   
    return true;   
}