根据RFC822的标准,将RFC822日期字符串转换成time_t时间。

最新推荐文章于 2024-04-18 08:55:27 发布

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最新推荐文章于 2024-04-18 08:55:27 发布

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文章标签： python c/c++

原文链接：http://www.cnblogs.com/cavancn/archive/2009/07/27/1531914.html

本文介绍了一种根据RFC822标准解析日期时间的方法，包括如何从字符串中提取日、月、年、时、分、秒及时区信息，并通过示例代码详细展示了整个解析过程。

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RFC822 的时间日期格式

Code
     date-time   =  [ day "," ] date time        ; dd mm yy
                                                 ;  hh:mm:ss zzz
     day         =  "Mon"  / "Tue" /  "Wed"  / "Thu"
                 /  "Fri"  / "Sat" /  "Sun"
     date        =  1*2DIGIT month 2DIGIT        ; day month year
                                                 ;  e.g. 20 Jun 82
     month       =  "Jan"  /  "Feb" /  "Mar"  /  "Apr"
                 /  "May"  /  "Jun" /  "Jul"  /  "Aug"
                 /  "Sep"  /  "Oct" /  "Nov"  /  "Dec"
     time        =  hour zone                    ; ANSI and Military
     hour        =  2DIGIT ":" 2DIGIT [":" 2DIGIT]
                                                 ; 00:00:00 - 23:59:59
     zone        =  "UT"  / "GMT"                ; Universal Time
                                                 ; North American : UT
                 /  "EST" / "EDT"                ;  Eastern:  - 5/ - 4
                 /  "CST" / "CDT"                ;  Central:  - 6/ - 5
                 /  "MST" / "MDT"                ;  Mountain: - 7/ - 6
                 /  "PST" / "PDT"                ;  Pacific:  - 8/ - 7
                 /  1ALPHA                       ; Military: Z = UT;
                                                 ;  A:-1; (J not used)
                                                 ;  M:-12; N:+1; Y:+12
                 / ( ("+" / "-") 4DIGIT )        ; Local differential
                                                 ;  hours+min. (HHMM)

下面是根据上述标准对日期时间的解析

Code
1

virtual HRESULT ParseTime(const NWString& strMIMETime)
2

{
3

CString str = TEXT("AAAA");
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CString strData(strMIMETime.c_str());
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static const TCHAR * const lpszMonthName[] =
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{TEXT("Jan"),TEXT("Feb"),TEXT("Mar"),TEXT("Apr"),TEXT("May"),
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TEXT("Jun"),TEXT("Jul"),TEXT("Aug"),TEXT("Sep"),TEXT("Oct"),
8

TEXT("Nov"),TEXT("Dec")};
9

strData.Trim(); //删去多余的空格
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INT nPosition = 0;
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if(*(LPCTSTR(strData) + 3) == TEXT(',')) //星期信息无用，跳过。
14

{
15

nPosition = 5;
16

}
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{//Fix bug: Microsoft NNTP Server return data format invalid,
19

//like "Tue,<SPACE><SPACE>26 May 2005

//We must detect and skip redundant SPACE.
22

while(*(LPCTSTR(strData) + nPosition) == TEXT(' '))
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++nPosition;
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}
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//天
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CString strTemp = strData.Tokenize(TEXT(" "), nPosition);
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UINT nDay = boost::lexical_cast<UINT>(LPCTSTR(strTemp));
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//月
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UINT nMonth = 0;
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strTemp = strData.Tokenize(TEXT(" "), nPosition);
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for(nMonth = 0; nMonth < 12; ++nMonth)
34

{
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if(strTemp == lpszMonthName[nMonth])
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break;
37

}
38

//年份
40

strTemp = LPCTSTR(strData.Tokenize(TEXT(" "), nPosition));
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UINT nYear = boost::lexical_cast<UINT>(LPCTSTR(strTemp));
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//小时
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strTemp = LPCTSTR(strData.Tokenize(TEXT(":"), nPosition));
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UINT nHour = boost::lexical_cast<UINT>(LPCTSTR(strTemp));
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//分钟
48

strTemp = LPCTSTR(strData.Tokenize(TEXT(":"), nPosition));
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UINT nMinute = boost::lexical_cast<UINT>(LPCTSTR(strTemp));
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//秒数
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UINT nSecond = 0;
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if(*(LPCTSTR(strData) + nPosition - 1) == TEXT(':'))
54

{
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strTemp = LPCTSTR(strData.Tokenize(TEXT(" "), nPosition));
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nSecond = boost::lexical_cast<UINT>(LPCTSTR(strTemp));
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}
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//最后处理时区
60

time_t nZoneOffset = 0;
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strTemp = strData.Tokenize(TEXT(" "), nPosition);
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//UT,GMT,EST,EDT,CST,CDT,MST,MDT,PST,PDT
63

if(3 == strTemp.GetLength())
64

{
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if(*(LPCTSTR(strTemp)) == TEXT('E') || *(LPCTSTR(strTemp)) == TEXT('e'))
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{
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if(*(LPCTSTR(strTemp) + 1) == TEXT('S') || *(LPCTSTR(strTemp) + 1) == TEXT('s'))
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nZoneOffset = -5 * 60 * 60;
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else//if(*(LPCTSTR(strTemp) + 1) == TEXT('D') || *(LPCTSTR(strTemp) + 1) == TEXT('d'))
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nZoneOffset = -4 * 60 * 60;
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}
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else if(*(LPCTSTR(strTemp)) == TEXT('C') || *(LPCTSTR(strTemp)) == TEXT('c'))
73

{
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if(*(LPCTSTR(strTemp) + 1) == TEXT('S') || *(LPCTSTR(strTemp) + 1) == TEXT('s'))
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nZoneOffset = -6 * 60 * 60;
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else//if(*(LPCTSTR(strTemp) + 1) == TEXT('D') || *(LPCTSTR(strTemp) + 1) == TEXT('d'))
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nZoneOffset = -5 * 60 * 60;
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}
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else if(*(LPCTSTR(strTemp)) == TEXT('M') || *(LPCTSTR(strTemp)) == TEXT('m'))
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{
81

if(*(LPCTSTR(strTemp) + 1) == TEXT('S') || *(LPCTSTR(strTemp) + 1) == TEXT('s'))
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nZoneOffset = -7 * 60 * 60;
83

else//if(*(LPCTSTR(strTemp) + 1) == TEXT('D') || *(LPCTSTR(strTemp) + 1) == TEXT('d'))
84

nZoneOffset = -6 * 60 * 60;
85

}
86

else if(*(LPCTSTR(strTemp)) == TEXT('P') || *(LPCTSTR(strTemp)) == TEXT('p'))
87

{
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if(*(LPCTSTR(strTemp) + 1) == TEXT('S') || *(LPCTSTR(strTemp) + 1) == TEXT('s'))
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nZoneOffset = -8 * 60 * 60;
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else//if(*(LPCTSTR(strTemp) + 1) == TEXT('D') || *(LPCTSTR(strTemp) + 1) == TEXT('d'))
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nZoneOffset = -7 * 60 * 60;
92

}
93

else //GMT and UT, the nZoneOffset = 0
94

{}
95

}
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//军方时区
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else if(1 == strTemp.GetLength())
98

{
99

if(*(LPCTSTR(strTemp)) >= TEXT('A') && *(LPCTSTR(strTemp)) <= TEXT('F'))
100

nZoneOffset = -60 * 60 * (*(LPCTSTR(strTemp)) - TEXT('A') + 1);
101

else if(*(LPCTSTR(strTemp)) >= TEXT('K') && *(LPCTSTR(strTemp)) <= TEXT('M'))
102

nZoneOffset = -60 * 60 * (*(LPCTSTR(strTemp)) - TEXT('A') + 2);
103

else if(*(LPCTSTR(strTemp)) >= TEXT('N') && *(LPCTSTR(strTemp)) <= TEXT('Y'))
104

nZoneOffset = 60 * 60 * (*(LPCTSTR(strTemp)) - TEXT('N') + 1);
105

else if(*(LPCTSTR(strTemp)) >= TEXT('a') && *(LPCTSTR(strTemp)) <= TEXT('f'))
106

nZoneOffset = -60 * 60 * (*(LPCTSTR(strTemp)) - TEXT('a') + 1);
107

else if(*(LPCTSTR(strTemp)) >= TEXT('k') && *(LPCTSTR(strTemp)) <= TEXT('m'))
108

nZoneOffset = -60 * 60 * (*(LPCTSTR(strTemp)) - TEXT('a') + 2);
109

else if(*(LPCTSTR(strTemp)) >= TEXT('n') && *(LPCTSTR(strTemp)) <= TEXT('y'))
110

nZoneOffset = 60 * 60 * (*(LPCTSTR(strTemp)) - TEXT('n') + 1);
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}
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//数字时区
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else
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{
115

int nTimeZone = boost::lexical_cast<int>(LPCTSTR(strTemp));
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nZoneOffset = (60 * (nTimeZone / 100) + nTimeZone % 100) * 60;
117

}
118

119

struct tm tmRet =

{nSecond, nMinute, nHour, nDay, nMonth, nYear, 0, 0, -1};
120

/**//* Fix up the year, using the RFC 2822 rules. Remember that tm_year stores the year - 1900. */
121

if (tmRet.tm_year < 50)
122

tmRet.tm_year += 100;
123

else if(tmRet.tm_year >= 1000)
124

tmRet.tm_year -= 1900;
125

126

m_tm = _mkgmtime(&tmRet) - nZoneOffset;
127

return S_OK;
128

}

转载于:https://www.cnblogs.com/cavancn/archive/2009/07/27/1531914.html