我使用以下代码来使用Dev C ++ 5.4.1读取多个.dat文件,目的是找到读取时间。但是,我正在尝试显示这些文件的内容,问题是显示数据(这是文本数据的记录)不是从头开始,例如,如果文件(如果是一个文件)包含60条记录则显示最近20条记录。现在,如果有多个文件,输出可能会跳过第一个文件或前两个文件并打印其余文件。我认为应该用Dev C ++修改一些东西,否则我的时间戳功能不正确。值得注意的是,当我逐行调试时,它可以很好地工作并从头开始显示!
#include <Windows.h>
#include <ctime>
#include <stdint.h>
#include <iostream>
using std::cout;
using std::endl;
#include <fstream>
using std::ifstream;
#include <cstring>
/* Returns the amount of milliseconds elapsed since the UNIX epoch. Works on both
* windows and linux. */
uint64_t GetTimeMs64()
{
FILETIME ft;
LARGE_INTEGER li;
/* Get the amount of 100 nano seconds intervals elapsed since January 1, 1601 (UTC) and copy it
* to a LARGE_INTEGER structure. */
GetSystemTimeAsFileTime(&ft);
li.LowPart = ft.dwLowDateTime;
li.HighPart = ft.dwHighDateTime;
uint64_t ret;
ret = li.QuadPart;
ret -= 116444736000000000LL; /* Convert from file time to UNIX epoch time. */
ret /= 10000; /* From 100 nano seconds (10^-7) to 1 millisecond (10^-3) intervals */
return ret;
}
const int MAX_CHARS_PER_LINE = 512;
const int MAX_TOKENS_PER_LINE = 20;
const char* const DELIMITER = "|";
int main()
{
// create a file-reading object
uint64_t a = GetTimeMs64();
cout << a << endl;
HANDLE h;
WIN32_FIND_DATA find_data;
h = FindFirstFile( "*.dat", & find_data );
if( h == INVALID_HANDLE_VALUE ) {
cout<<"error"<<endl;
}
do {
char * s = find_data.cFileName;
ifstream fin;
fin.open(s); // open a file
if (!fin.good())
return 1; // exit if file not found
// read each line of the file
while (!fin.eof())
{
// read an entire line into memory
char buf[MAX_CHARS_PER_LINE];
fin.getline(buf, MAX_CHARS_PER_LINE);
// parse the line into blank-delimited tokens
int n = 0; // a for-loop index
// array to store memory addresses of the tokens in buf
const char* token[MAX_TOKENS_PER_LINE] = {}; // initialize to 0
// parse the line
token[0] = strtok(buf, DELIMITER); // first token
if (token[0]) // zero if line is blank
{
for (n = 1; n < MAX_TOKENS_PER_LINE; n++)
{
token[n] = strtok(0, DELIMITER); // subsequent tokens
if (!token[n]) break; // no more tokens
}
}
// process (print) the tokens
for (int i = 0; i < n; i++) // n = #of tokens
cout << "Token[" << i << "] = " << token[i] << endl;
cout << endl;
}
// Your code here
} while( FindNextFile( h, & find_data ) );
FindClose( h );
uint64_t b = GetTimeMs64();
cout << a << endl;
cout << b << endl;
uint64_t c = b - a;
cout << c << endl;
system("pause");
}