asked on

cftime function is not declared when compile by g++

program: test.cc
#include <stdio.h>
#include <time.h>
main() {
printf("Hello!\n");

char temp[2048];
char timestamp[20];
struct timeval timeval;
gettimeofday( &timeval, 0 );
cftime( timestamp, (char *)"%h %d %H:%M:%S", &(timeval.tv_sec) );

Then the folloing errors output when i compile by using g++,
>g++ -g test.cc
test.cc: In function `int main()':
test.cc:10: error: `cftime' undeclared (first use this function)
test.cc:10: error: (Each undeclared identifier is reported only once for each fu
nction it appears in.)

This is not a problem if i use gcc and reanme the program from test.cc to test.c.
However, i need to use g++.

jkr

There is no such thing as 'cftime()' - I assume you meant 'ctime()':

CTIME(3) Linux Programmer's Manual CTIME(3)

NAME
asctime, ctime, gmtime, localtime, mktime - transform
binary date and time to ASCII

SYNOPSIS
#include <time.h>

char *asctime(const struct tm *timeptr);

char *ctime(const time_t *timep);

struct tm *gmtime(const time_t *timep);

struct tm *localtime(const time_t *timep);

time_t mktime(struct tm *timeptr);

extern char *tzname[2];

So, change

cftime( timestamp, (char *)"%h %d %H:%M:%S", &(timeval.tv_sec) );

to read

ctime( timestamp, (char *)"%h %d %H:%M:%S", &(timeval.tv_sec) );

and it should work.

long int timezone;
extern int daylight;

DESCRIPTION
The ctime(), gmtime() and localtime() functions all take
an argument of data type time_t which represents calendar
time. When interpreted as an absolute time value, it rep
resents the number of seconds elapsed since 00:00:00 on
January 1, 1970, Coordinated Universal Time (UTC).

jkr

Ooops, sorry, editing error - apart from the man page, that should have beeen

There is no such thing as 'cftime()' - I assume you meant 'ctime()'
So, change

cftime( timestamp, (char *)"%h %d %H:%M:%S", &(timeval.tv_sec) );

to read

ctime( timestamp, (char *)"%h %d %H:%M:%S", &(timeval.tv_sec) );

and it should work.

avizit

There does seem to be a 'cftime()' function

http://www.scit.wlv.ac.uk/cgi-bin/mansec?3C+cftime

ASKER CERTIFIED SOLUTION

avizit

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