Re: [Boost-users] [date_time] howto determine date format?

BOOST_FOREACH(std: :string const

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std: :istringstream iss(s); iss.imbue(std: :locale(iss.getloc(), input_facet));

Content-type: text/plain; charset=UTF-8 Date: Thu, 15 Apr 2010 23:47:31 -0400 Message-id: <1271389651.25933.26.camel@localhost> MIME-version: 1.0 X-Mailer: Evolution 2.28.3 (2.28.3-1.fc12) Content-transfer-encoding: 7bit On 2010-02-24 14:08, Markus Werle wrote:

Hi!

With the code below I try to automagically determine the date format found in input files. I'd expect the code below to find the date format "%d.%m.%Y" for "05.02.2008", but I got surprised by obtaining "%m/%d/%Y". A major pain it is with those dates. Whether my shallow knowledge of locales and imbue or boost::date_time (from boost-1.37.0) is to be blamed is beyond my horizon.

I feel like date accepts '.' where I said "expect '/'", so I think this should be changed. I may be wrong.

Could you please shed some light on the issue?

Thanks, Markus

#include

#include #include #include #include #include

#include <string> #include <list>

inline std::string determine_date_format(std::string const

I'm having the similar problems, with similar code. It's aggravating. Oh, yeah, I have boost-1.39.0-9.fc12.x86_64. This is what happens when I run the executable: echo "1230735660" | ./dateIO 5660-Dec-07 00:00:00 %m/%d/%Y %H:%M:%S It thinks 1230735660 is in the format %m/%d/%Y %H:%M:%S, as if 3 were the separator, which then produces m=12, d=07 and Y=5660. How come? If I want / to be the separator, then / should be the separator, not 3. And this is the code: // g++ -g -Wall -o dateIO dateIO.C -lboost_date_time #include <iostream> #include <sstream> #include <cstdlib> #include <string> #include using namespace boost::posix_time; using namespace std; // Known date formats. const char * knownFormats[]={ "%Y-%m-%d %H:%M:%S", "%Y-%m-%d, %H:%M:%S", "%Y/%m/%d %H:%M:%S", "%Y/%m/%d, %H:%M:%S", "%m/%d/%Y %H:%M:%S", "%m/%d/%Y, %H:%M:%S", "%m-%d-%Y %H:%M:%S", "%m-%d-%Y, %H:%M:%S", "%b %d, %Y %H:%M:%S", "%Y-%b-%d %H:%M:%S", "%Y-%b-%d, %H:%M:%S", 0 }; ptime readDateGivenFormat(istream & IN, const char * fmt) { ptime pt(not_a_date_time); // Always allocate facet with new! Only locale can destroy it because // facet's destructor is not public (and locale is a friend). // // Thank you Angelika Langer! Long live Angelika Langer! //http://www.angelikalanger.com/Conferences/Slides/CppLocales-ACCU-2001.pdf time_input_facet * tifacet = new time_input_facet(fmt); locale loc(IN.getloc(),tifacet); IN.imbue(loc); IN >> pt; return pt; } int datestr2ptime(const char * datestr, ptime & pt) { istringstream * INSTR=0; int i=0; pt=ptime(not_a_date_time); // Can't read it in a loop from stdin, because once read, // it won't be read again! // Keep creating a new istringstream bound to datestr for each // known format. while(knownFormats[i]!=0){ // Put it into INSTR - each time with new! INSTR = new istringstream(datestr); pt=readDateGivenFormat(*INSTR, knownFormats[i]); delete INSTR; if(pt!=not_a_date_time) return i; i++; } return i; } int main(int argc, char * argv[]) { ptime pt(not_a_date_time); string datestr; int i=-1; getline(cin,datestr); i=datestr2ptime(datestr.c_str(), pt); cout << pt; if(knownFormats[i]) cout << "\t" << knownFormats[i]; cout << endl; return 0; }