Namespace
Varianti

strftime

Da cppreference.com.
< c‎ | chrono

 
 
Data e ora utilità
Funzioni
Original:
Functions
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Tempo di manipolazione
Original:
Time manipulation
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difftime
time
clock
Formato conversioni
Original:
Format conversions
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asctime
ctime
strftime
wcsftime
gmtime
localtime
mktime
Costanti
Original:
Constants
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CLOCKS_PER_SEC
Tipi
Original:
Types
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tm
time_t
clock_t
 
Defined in header <time.h>
size_t strftime( char* str, size_t count, const char* format, tm* time );
Converte la data e l'ora da un calendario time dato il tempo di terminazione null stringa a caratteri multibyte str secondo format formato stringa. Fino a count byte vengono scritti.
Original:
Converts the date and time information from a given calendar time time to a null-terminated multibyte character string str according to format string format. Up to count bytes are written.
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Indice

[modifica] Parametri

str -
puntatore al primo elemento della matrice char per l'uscita
Original:
pointer to the first element of the char array for output
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count -
Numero massimo di byte da scrivere
Original:
maximum number of bytes to write
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format -
puntatore ad una stringa con terminazione null di caratteri multibyte che specifica il formato di conversione.
La stringa di formato è composto da zero o più identificatori di conversione e personaggi ordinari (tranne %). Tutti i personaggi ordinari, incluso il carattere nullo di terminazione, vengono copiati nella stringa di output senza modifiche. Ogni specifica di conversione inizia con il carattere %, eventualmente seguita da E o modificatore O (ignorato se non supportato dal locale), seguito dal carattere che determina il comportamento del committente. Gli identificatori di formato sono disponibili i seguenti:
Original:
The format string consists of zero or more conversion specifiers and ordinary characters (except %). All ordinary characters, including the terminating null character, are copied to the output string without modification. Each conversion specification begins with % character, optionally followed by E or O modifier (ignored if unsupported by the locale), followed by the character that determines the behavior of the specifier. The following format specifiers are available:
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Conversion
specifier
Explanation Used fields
% writes literal %. The full conversion specification must be %%.
n(C++11) writes newline character
t(C++11) writes horizontal tab character
Year
Y writes year as a 4 digit decimal number tm_year
EY(C++11) writes year in the alternative representation, e.g.平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale tm_year
y writes last 2 digits of year as a decimal number (range [00,99]) tm_year
Oy(C++11) writes last 2 digits of year using the alternative numeric system, e.g. 十一 instead of 11 in ja_JP locale tm_year
Ey(C++11) writes year as offset from locale's alternative calendar period %EC (locale-dependent) tm_year
C(C++11) writes first 2 digits of year as a decimal number (range [00,99]) tm_year
EC(C++11) writes name of the base year (period) in the locale's alternative representation, e.g. 平成 (Heisei era) in ja_JP tm_year
G(C++11) writes ISO 8601 week-based year, i.e. the year that contains the specified week.
In IS0 8601 settimana inizia con Lunedi e la prima settimana dell'anno devono soddisfare i seguenti requisiti:
Original:
In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
  • Include 4 gennaio
    Original:
    Includes January 4
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
  • Include prima Giovedi dell'anno
    Original:
    Includes first Thursday of the year
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
tm_year, tm_wday, tm_yday
g(C++11) writes last 2 digits of ISO 8601 week-based year, i.e. the year that contains the specified week (range [00,99]).
In IS0 8601 settimana inizia con Lunedi e la prima settimana dell'anno devono soddisfare i seguenti requisiti:
Original:
In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
  • Include 4 gennaio
    Original:
    Includes January 4
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
  • Include prima Giovedi dell'anno
    Original:
    Includes first Thursday of the year
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
tm_year, tm_wday, tm_yday
Month
b writes abbreviated month name, e.g. Oct (locale dependent) tm_mon
h(C++11) synonym of b tm_mon
B writes full month name, e.g. October (locale dependent) tm_mon
m writes month as a decimal number (range [01,12]) tm_mon
Om(C++11) writes month using the alternative numeric system, e.g. 十二 instead of 12 in ja_JP locale tm_mon
Week
U writes week of the year as a decimal number (Sunday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OU(C++11) writes week of the year, as by %U, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
W writes week of the year as a decimal number (Monday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OW(C++11) writes week of the year, as by %W, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
V(C++11) writes ISO 8601 week of the year (range [01,53]).
In IS0 8601 settimana inizia con Lunedi e la prima settimana dell'anno devono soddisfare i seguenti requisiti:
Original:
In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
  • Include 4 gennaio
    Original:
    Includes January 4
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
  • Include prima Giovedi dell'anno
    Original:
    Includes first Thursday of the year
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
tm_year, tm_wday, tm_yday
OV(C++11) writes week of the year, as by %V, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
Day of the year/month
j writes day of the year as a decimal number (range [001,366]) tm_yday
d writes day of the month as a decimal number (range [01,31]) tm_mday
Od(C++11) writes zero-based day of the month using the alternative numeric system, e.g 二十七 instead of 23 in ja_JP locale
Singolo carattere è preceduto da uno spazio.
Original:
Single character is preceded by a space.
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tm_mday
e(C++11) writes day of the month as a decimal number (range [1,31]).
Cifra singola è preceduta da uno spazio.
Original:
Single digit is preceded by a space.
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tm_mday
Oe(C++11) writes one-based day of the month using the alternative numeric system, e.g. 二十七 instead of 27 in ja_JP locale
Singolo carattere è preceduto da uno spazio.
Original:
Single character is preceded by a space.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
tm_mday
Day of the week
a writes abbreviated weekday name, e.g. Fri (locale dependent) tm_wday
A writes full weekday name, e.g. Friday (locale dependent) tm_wday
w writes weekday as a decimal number, where Sunday is 0 (range [0-6]) tm_wday
Ow(C++11) writes weekday, where Sunday is 0, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
u(C++11) writes weekday as a decimal number, where Monday is 1 (ISO 8601 format) (range [1-7]) tm_wday
Ou(C++11) writes weekday, where Monday is 1, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
Hour, minute, second
H writes hour as a decimal number, 24 hour clock (range [00-23]) tm_hour
OH(C++11) writes hour from 24-hour clock using the alternative numeric system, e.g. 十八 instead of 18 in ja_JP locale tm_hour
I writes hour as a decimal number, 12 hour clock (range [01,12]) tm_hour
OI(C++11) writes hour from 12-hour clock using the alternative numeric system, e.g. 六 instead of 06 in ja_JP locale tm_hour
M writes minute as a decimal number (range [00,59]) tm_min
OM(C++11) writes minute using the alternative numeric system, e.g. 二十五 instead of 25 in ja_JP locale tm_min
S writes second as a decimal number (range [00,60]) tm_sec
OS(C++11) writes second using the alternative numeric system, e.g. 二十四 instead of 24 in ja_JP locale tm_sec
Other
c writes standard date and time string, e.g. Sun Oct 17 04:41:13 2010 (locale dependent) all
Ec(C++11) writes alternative date and time string, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
x writes localized date representation (locale dependent) all
Ex(C++11) writes alternative date representation, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
X writes localized time representation (locale dependent) all
EX(C++11) writes alternative time representation (locale dependent) all
D(C++11) equivalent to "%m/%d/%y" tm_mon, tm_mday, tm_year
F(C++11) equivalent to "%Y-%m-%d" (the ISO 8601 date format) tm_mon, tm_mday, tm_year
r(C++11) writes localized 12-hour clock time (locale dependent) tm_hour, tm_min, tm_sec
R(C++11) equivalent to "%H:%M" tm_hour, tm_min
T(C++11) equivalent to "%H:%M:%S" (the ISO 8601 time format) tm_hour, tm_min, tm_sec
p writes localized a.m. or p.m. (locale dependent) tm_hour
z(C++11) writes offset from UTC in the ISO 8601 format (e.g. -0430), or no characters if the time zone information is not available tm_isdst
Z writes time zone name or abbreviation, or no characters if the time zone information is not available (locale dependent) tm_isdst
Original:
pointer to a null-terminated multibyte character string specifying the format of conversion.
La stringa di formato è composto da zero o più identificatori di conversione e personaggi ordinari (tranne %). Tutti i personaggi ordinari, incluso il carattere nullo di terminazione, vengono copiati nella stringa di output senza modifiche. Ogni specifica di conversione inizia con il carattere %, eventualmente seguita da E o modificatore O (ignorato se non supportato dal locale), seguito dal carattere che determina il comportamento del committente. Gli identificatori di formato sono disponibili i seguenti:
Original:
The format string consists of zero or more conversion specifiers and ordinary characters (except %). All ordinary characters, including the terminating null character, are copied to the output string without modification. Each conversion specification begins with % character, optionally followed by E or O modifier (ignored if unsupported by the locale), followed by the character that determines the behavior of the specifier. The following format specifiers are available:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Conversion
specifier
Explanation Used fields
% writes literal %. The full conversion specification must be %%.
n(C++11) writes newline character
t(C++11) writes horizontal tab character
Year
Y writes year as a 4 digit decimal number tm_year
EY(C++11) writes year in the alternative representation, e.g.平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale tm_year
y writes last 2 digits of year as a decimal number (range [00,99]) tm_year
Oy(C++11) writes last 2 digits of year using the alternative numeric system, e.g. 十一 instead of 11 in ja_JP locale tm_year
Ey(C++11) writes year as offset from locale's alternative calendar period %EC (locale-dependent) tm_year
C(C++11) writes first 2 digits of year as a decimal number (range [00,99]) tm_year
EC(C++11) writes name of the base year (period) in the locale's alternative representation, e.g. 平成 (Heisei era) in ja_JP tm_year
G(C++11) writes ISO 8601 week-based year, i.e. the year that contains the specified week.
In IS0 8601 settimana inizia con Lunedi e la prima settimana dell'anno devono soddisfare i seguenti requisiti:
Original:
In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
  • Include 4 gennaio
    Original:
    Includes January 4
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
  • Include prima Giovedi dell'anno
    Original:
    Includes first Thursday of the year
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
tm_year, tm_wday, tm_yday
g(C++11) writes last 2 digits of ISO 8601 week-based year, i.e. the year that contains the specified week (range [00,99]).
In IS0 8601 settimana inizia con Lunedi e la prima settimana dell'anno devono soddisfare i seguenti requisiti:
Original:
In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
  • Include 4 gennaio
    Original:
    Includes January 4
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
  • Include prima Giovedi dell'anno
    Original:
    Includes first Thursday of the year
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
tm_year, tm_wday, tm_yday
Month
b writes abbreviated month name, e.g. Oct (locale dependent) tm_mon
h(C++11) synonym of b tm_mon
B writes full month name, e.g. October (locale dependent) tm_mon
m writes month as a decimal number (range [01,12]) tm_mon
Om(C++11) writes month using the alternative numeric system, e.g. 十二 instead of 12 in ja_JP locale tm_mon
Week
U writes week of the year as a decimal number (Sunday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OU(C++11) writes week of the year, as by %U, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
W writes week of the year as a decimal number (Monday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OW(C++11) writes week of the year, as by %W, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
V(C++11) writes ISO 8601 week of the year (range [01,53]).
In IS0 8601 settimana inizia con Lunedi e la prima settimana dell'anno devono soddisfare i seguenti requisiti:
Original:
In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
  • Include 4 gennaio
    Original:
    Includes January 4
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
  • Include prima Giovedi dell'anno
    Original:
    Includes first Thursday of the year
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
tm_year, tm_wday, tm_yday
OV(C++11) writes week of the year, as by %V, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
Day of the year/month
j writes day of the year as a decimal number (range [001,366]) tm_yday
d writes day of the month as a decimal number (range [01,31]) tm_mday
Od(C++11) writes zero-based day of the month using the alternative numeric system, e.g 二十七 instead of 23 in ja_JP locale
Singolo carattere è preceduto da uno spazio.
Original:
Single character is preceded by a space.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
tm_mday
e(C++11) writes day of the month as a decimal number (range [1,31]).
Cifra singola è preceduta da uno spazio.
Original:
Single digit is preceded by a space.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
tm_mday
Oe(C++11) writes one-based day of the month using the alternative numeric system, e.g. 二十七 instead of 27 in ja_JP locale
Singolo carattere è preceduto da uno spazio.
Original:
Single character is preceded by a space.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
tm_mday
Day of the week
a writes abbreviated weekday name, e.g. Fri (locale dependent) tm_wday
A writes full weekday name, e.g. Friday (locale dependent) tm_wday
w writes weekday as a decimal number, where Sunday is 0 (range [0-6]) tm_wday
Ow(C++11) writes weekday, where Sunday is 0, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
u(C++11) writes weekday as a decimal number, where Monday is 1 (ISO 8601 format) (range [1-7]) tm_wday
Ou(C++11) writes weekday, where Monday is 1, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
Hour, minute, second
H writes hour as a decimal number, 24 hour clock (range [00-23]) tm_hour
OH(C++11) writes hour from 24-hour clock using the alternative numeric system, e.g. 十八 instead of 18 in ja_JP locale tm_hour
I writes hour as a decimal number, 12 hour clock (range [01,12]) tm_hour
OI(C++11) writes hour from 12-hour clock using the alternative numeric system, e.g. 六 instead of 06 in ja_JP locale tm_hour
M writes minute as a decimal number (range [00,59]) tm_min
OM(C++11) writes minute using the alternative numeric system, e.g. 二十五 instead of 25 in ja_JP locale tm_min
S writes second as a decimal number (range [00,60]) tm_sec
OS(C++11) writes second using the alternative numeric system, e.g. 二十四 instead of 24 in ja_JP locale tm_sec
Other
c writes standard date and time string, e.g. Sun Oct 17 04:41:13 2010 (locale dependent) all
Ec(C++11) writes alternative date and time string, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
x writes localized date representation (locale dependent) all
Ex(C++11) writes alternative date representation, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
X writes localized time representation (locale dependent) all
EX(C++11) writes alternative time representation (locale dependent) all
D(C++11) equivalent to "%m/%d/%y" tm_mon, tm_mday, tm_year
F(C++11) equivalent to "%Y-%m-%d" (the ISO 8601 date format) tm_mon, tm_mday, tm_year
r(C++11) writes localized 12-hour clock time (locale dependent) tm_hour, tm_min, tm_sec
R(C++11) equivalent to "%H:%M" tm_hour, tm_min
T(C++11) equivalent to "%H:%M:%S" (the ISO 8601 time format) tm_hour, tm_min, tm_sec
p writes localized a.m. or p.m. (locale dependent) tm_hour
z(C++11) writes offset from UTC in the ISO 8601 format (e.g. -0430), or no characters if the time zone information is not available tm_isdst
Z writes time zone name or abbreviation, or no characters if the time zone information is not available (locale dependent) tm_isdst
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[modifica] Valore di ritorno

numero di byte scritti nell'array di caratteri puntato da str escluso il '\0' chiude in caso di successo. Se count è stato raggiunto prima che l'intera stringa può essere memorizzato, 0 viene restituito e il contenuto non sono definiti.
Original:
number of bytes written into the character array pointed to by str not including the terminating '\0' on success. If count was reached before the entire string could be stored, 0 is returned and the contents are undefined.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[modifica] Esempio

#include <stdio.h>
#include <time.h>
 
int main()
{
    char buff[50] = {0};
    struct tm _tm = {0};
    _tm.tm_year=112; // = year 2012
    _tm.tm_mon=9;    // = 10th month
    _tm.tm_mday=9;   // = 9th day
    _tm.tm_hour=8;   // = 8 hours
    _tm.tm_min=10;   // = 10 minutes
    _tm.tm_sec=20;   // = 20 secs
    if(strftime(buff,50,"%Y-%m-%d %H:%M:%S",&_tm) != 19)
        puts("Error!");
    else
        puts(buff);
 
    return 0;
}

Output:

2012-10-09 08:10:20

[modifica] Vedi anche

converte un oggetto time_t di una rappresentazione testuale
Original:
converts a time_t object to a textual representation
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(funzione) [edit]
converte un oggetto tm di una rappresentazione testuale
Original:
converts a tm object to a textual representation
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You can help to correct and verify the translation. Click here for instructions.

(funzione) [edit]
converte un oggetto personalizzato per tm rappresentazione di stringa testuale ampio
Original:
converts a tm object to custom wide string textual representation
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(funzione) [edit]
C++ documentation for strftime