使用"time.h"时崩溃
Crash when using "time.h"
==此行之后的最后一堂课===
这不是std::ostringstream的问题，我对"time.h"做了一些我不完全理解的坏事。原来的问题出现在课后。最后一个类看起来是这样的：
时间戳.h
#ifndef __TIMESTAMP_H
#define __TIMESTAMP_H
#include <string>
#include "time.h"
class CTimestamp {
private:
std::string timestamp;
time_t rawtime;
struct tm errorTime;
struct tm tempTime;
bool quality;
public:
CTimestamp();
void set(std::string inputTime);
std::string get();
std::string get(int modifiedBy);
bool good();
void getWeekday(); // Mainly for testing purposes - if this returns
// the correct weekday for your modified timestamp,
// you probably modified it correctly.
};
#endif
时间戳.cpp
#include "timestamp.h"
#include "time.h"
#include <string>
#include <stdlib.h>
#include <iostream>
#include <sstream>
CTimestamp::CTimestamp(){
quality = 0;
}
void CTimestamp::set(std::string inputTime){
quality = 1;
int year, month, day, hour, minute, second;
if (19 == inputTime.length()){
inputTime.replace(10,1," ");
inputTime.replace(13,1,":");
inputTime.replace(16,1,":");
year = atoi(inputTime.substr(0,4).c_str());
month = atoi(inputTime.substr(5,2).c_str());
day = atoi(inputTime.substr(8,2).c_str());
hour = atoi(inputTime.substr(11,2).c_str());
minute = atoi(inputTime.substr(14,2).c_str());
second = atoi(inputTime.substr(17,2).c_str());
timestamp = inputTime;
}
else{
quality = 0;
}
if(quality){
// Get current time with the "time_t time(struct tm * timeptr)" function from time.h
time(&rawtime);
// Change to local time with "struct tm * localtime (const time_t * timer)" function from time.h
errorTime = *localtime(&rawtime);
// Change to the time of the timestamp
errorTime.tm_year = year - 1900; //Years since 1900
errorTime.tm_mon = month - 1; //Months since january
errorTime.tm_mday = day; //Day of the month
errorTime.tm_hour = hour; //Hours since midnight
errorTime.tm_min = minute; //minutes since hour
errorTime.tm_sec = second; //Seconds since minute
// modifies errorTime so overflows in lower units increment higher units then sets tm_wday and tm_yday
mktime ( &errorTime );
}
}
void CTimestamp::getWeekday(){
const char * weekday[] = {"sun", "mon", "tue", "wed", "thu", "fri", "sat"};
std::cout << weekday[errorTime.tm_wday];
}
std::string CTimestamp::get(){
std::string returnValue = "Bad Initialization";
if(quality){
returnValue = timestamp;
}
return returnValue;
}
std::string CTimestamp::get(int modifiedBy){
std::string returnValue = "Bad Initialization";
if(quality){
tempTime = errorTime;
tempTime.tm_sec = (errorTime.tm_sec+modifiedBy);
mktime( &tempTime);
std::string year, month, day, hour, minute, second;
// This compiler does not support the C++11 std::to_string but there is a workaround with stringstreams
// http://www.cplusplus.com/articles/D9j2Nwbp/
year = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime.tm_year+1900)) )->str();
month = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime.tm_mon+1)) )->str();
day = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime.tm_mday)) )->str();
hour = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime.tm_hour)) )->str();
minute = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime.tm_min)) )->str();
second = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime.tm_sec)) )->str();
if(month.length() == 1) { month = "0" + month; }
if(day.length() == 1) { day = "0" + day; }
if(hour.length() == 1) { hour = "0" + hour; }
if(minute.length() == 1) { minute = "0" + minute; }
if(second.length() == 1) { second = "0" + second; }
returnValue = year+"-"+month+"-"+day+" "+hour+":"+minute+":"+second;
}
return returnValue;
}
bool CTimestamp::good(){
return quality;
}
===原始问题从此行下方开始===
我需要一些自定义时间戳功能，我正试图为它创建一个类。不幸的是，当我试图调用其中一个函数时，它会崩溃我的程序，我不太确定为什么，尤其是考虑到当我在一个较小的玩具程序中使用它来测试类时，它不会崩溃。
#ifndef __TIMESTAMP_H
#define __TIMESTAMP_H
#include <string>
#include "time.h"
#include "debug.h"
class CTimestamp {
private:
std::string timestamp;
time_t rawtime;
struct tm * errorTime;
struct tm * tempTime;
bool quality;
public:
CTimestamp();
void set(std::string inputTime);
std::string get();
std::string get(int modifiedBy);
bool good();
void getWeekday(); // Mainly for testing purposes - if this returns
// the correct weekday for your modified timestamp,
// you probably modified it correctly.
};
#endif
当我呼叫时出现问题
std::cout << timeStamp.get(-30);
具体来说，在这一点上：
year = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_year+1900)) )->str();
这是以下方法的一部分：
std::string CTimestamp::get(int modifiedBy){
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
std::string returnValue = "Bad Initialization";
if(quality){
tempTime->tm_year = errorTime->tm_year;
tempTime->tm_mon = errorTime->tm_mon;
tempTime->tm_mday = errorTime->tm_mday;
tempTime->tm_hour = errorTime->tm_hour;
tempTime->tm_min = errorTime->tm_min;
tempTime->tm_sec = errorTime->tm_sec;
mktime(tempTime);
tempTime->tm_sec = tempTime->tm_sec + modifiedBy;
mktime(tempTime);
std::string year, month, day, hour, minute, second;
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
// This compiler does not support the C++11 std::to_string but there is a workaround with stringstreams
// http://www.cplusplus.com/articles/D9j2Nwbp/
year = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_year+1900)) )->str();
month = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_mon+1)) )->str();
day = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_mday)) )->str();
hour = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_hour)) )->str();
minute = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_min)) )->str();
second = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_sec)) )->str();
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
if(month.length() == 1)
{
month = "0" + month;
}
if(day.length() == 1)
{
day = "0" + day;
}
if(hour.length() == 1)
{
hour = "0" + hour;
}
if(minute.length() == 1)
{
minute = "0" + minute;
}
if(second.length() == 1)
{
second = "0" + second;
}
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
returnValue = year+"-"+month+"-"+day+" "+hour+":"+minute+":"+second;
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
}
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
return returnValue;
}
编辑
好吧，这让我很奇怪：
当我呼叫时
std::cout << timeStamp.get();
它在我指示的线路上崩溃了。
当我改为
std::string hey = timeStamp.get();
std::cout << hey;
它在第二个__DEBUG__语句（就在if(quality)之后）上崩溃
编辑编辑
errorTime在此处初始化：
void CTimestamp::set(std::string inputTime){
quality = 1;
int year, month, day, hour, minute, second;
if (19 == inputTime.length()){
inputTime.replace(10,1," ");
inputTime.replace(13,1,":");
inputTime.replace(16,1,":");
year = atoi(inputTime.substr(0,4).c_str());
month = atoi(inputTime.substr(5,2).c_str());
day = atoi(inputTime.substr(8,2).c_str());
hour = atoi(inputTime.substr(11,2).c_str());
minute = atoi(inputTime.substr(14,2).c_str());
second = atoi(inputTime.substr(17,2).c_str());
timestamp = inputTime;
}
else{
quality = 0;
}
if(quality){
// Get current time with the "time_t time(struct tm * timeptr)" function from time.h
time(&rawtime);
// Change to local time
errorTime = localtime(&rawtime);
// Change to the time of the timestamp
errorTime->tm_year = year - 1900; //Years since 1900
errorTime->tm_mon = month - 1; //Months since january
errorTime->tm_mday = day; //Day of the month
errorTime->tm_hour = hour; //Hours since midnight
errorTime->tm_min = minute; //minutes since hour
errorTime->tm_sec = second; //Seconds since minute
// modifies errorTime so overflows in lower units increment higher units then sets tm_wday and tm_yday
mktime ( errorTime );
}
}
编辑编辑
我试着去掉花哨的指针工作，让它多占用几行。不幸的是，它似乎没有起作用：
/*
year = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_year+1900)) )->str();
month = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_mon+1)) )->str();
day = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_mday)) )->str();
hour = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_hour)) )->str();
minute = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_min)) )->str();
second = static_cast<std::ostringstream*>( &(std::ostringstream() << (tempTime->tm_sec)) )->str();
*/
int timeConvertINT;
std::ostringstream timeConvertOSS;
timeConvertINT = (tempTime->tm_year)+1900;
timeConvertOSS << timeConvertINT;
year = timeConvertOSS.str();
timeConvertINT = (tempTime->tm_mon)+1;
timeConvertOSS << timeConvertINT;
month = timeConvertOSS.str();
timeConvertINT = (tempTime->tm_mday);
timeConvertOSS << timeConvertINT;
day = timeConvertOSS.str();
timeConvertINT = (tempTime->tm_hour);
timeConvertOSS << timeConvertINT;
hour = timeConvertOSS.str();
timeConvertINT = (tempTime->tm_min);
timeConvertOSS << timeConvertINT;
minute = timeConvertOSS.str();
timeConvertINT = (tempTime->tm_sec);
timeConvertOSS << timeConvertINT;
second = timeConvertOSS.str();
编辑编辑
嗯。因此，ostreamstring似乎不是这里的罪犯——即使我注释掉所有OSS功能并硬编码回复，它也会在这一行崩溃。
这意味着在这个区块中：
if(quality){
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
tempTime->tm_year = errorTime->tm_year;
tempTime->tm_mon = errorTime->tm_mon;
tempTime->tm_mday = errorTime->tm_mday;
tempTime->tm_hour = errorTime->tm_hour;
tempTime->tm_min = errorTime->tm_min;
tempTime->tm_sec = errorTime->tm_sec;
mktime(tempTime);
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
tempTime->tm_sec = tempTime->tm_sec + modifiedBy;
mktime(tempTime);
std::string year, month, day, hour, minute, second;
if ( 1 < __DEBUG__ ){std::cout << "nDEBUG " << __FILE__ << " " << __FUNCTION__ << " " << __LINE__ ;}
year = "2013";
month = "11";
day = "05";
hour = "12";
minute = "00";
second = "00";
当调用时，我看到了第一个调试输出（以后没有）
std::string hey = timeStamp.get();
std::cout << hey;
但当我称之为时
std::cout << timeStamp.get();
我看到之后的调试输出
std::string year, month, day, hour, minute, second;
神秘的崩溃和指针在一起，因此在取消引用它们之前，请检查tempTime和errorTime是否指向有效对象。发布的代码没有显示在哪里初始化tempTime，所以这是开始查找的地方。
除了为指针赋值外，请确保在使用指针时对象的生存期仍然有效。您不希望保存指向超出范围的临时对象的指针。
代码"看起来"合法，但形式上——它实际上是不正确的，因为你使用的是临时的地址。&(std::ostringstream() << (tempTime->tm_year+1900))。
您可以很容易地避免它——只需编写(std::ostringstream() << (tempTime->tm_year+1900)).str()。如果它仍然崩溃-试着给std:：ostingstream（）一个名称，比如
std::ostringstream() oss;
oss << (tempTime->tm_year+1900);
oss.str();
如果这也无济于事的话——我现在没有主意了。
相关文章：
- 当回溯以零开始时，如何调试崩溃
- 内联映射初始化的动态atexit析构函数崩溃
- 执行函数时导致崩溃的变量
- 程序崩溃并显示"std：：out_of_range"错误
- CoInitialize(）在单独的线程上崩溃而不返回
- 使用调试/崩溃报告将应用程序部署到客户端
- 为什么所有C++编译器都会崩溃或挂起此代码
- 为什么lambda在clang上崩溃而不是在gcc上崩溃
- 为什么我的多线程作业队列崩溃
- ExtractIconEx:可以工作，但偶尔会崩溃
- 为什么引用传递会导致此崩溃(C++）
- 试图创建流或fopen时程序崩溃
- 类对象数组的问题会导致崩溃
- 排序时无法执行交换操作.我做的时候它会崩溃.为什么
- 为什么要增加导致崩溃的指针
- 在虚幻引擎中删除NXOpen对象时崩溃
- 为什么它只打印双链接列表的第一个值，而我的程序却崩溃了
- 应用程序崩溃并显示"symbol _ZdlPvm, version Qt_5 not defined in file libQt5Core.so.5 with link time reference"
- Visual Studio在尝试读取resource.txt文件时崩溃
- 使用"time.h"时崩溃
