Handy formatting and conversion routines.

Functions
int	extractISOTime (char *timestr, struct tm *utm)
int	f_scansexa (const char *str0, double *dp)
int	fs_sexa (char *out, double a, int w, int fracbase)
void	getSexComponents (double value, int *d, int *m, int *s)
double	JDtoGMST (double jd)
int	numberFormat (char *buf, const char *format, double value)
const char *	timestamp (void)
double	UTtoJD (struct tm *utm)

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Function Documentation

int extractISOTime	(	char *	timestr,
		struct tm *	utm
	)

Extract ISO 8601 time and store it in a tm struct.

Parameters:

	timestr	a string containing date and time in ISO 8601 format.
	utm	a pointer to a tm structure to store the extracted time and date.

Returns:

0 on success, -1 on failure.

int f_scansexa	(	const char *	str0,
		double *	dp
	)

convert sexagesimal string str AxBxC to double.

x can be anything non-numeric. Any missing A, B or C will be assumed 0. Optional - and + can be anywhere.

Parameters:

	str0	string containing sexagesimal number.
	dp	pointer to a double to store the sexagesimal number.

Returns:

return 0 if ok, -1 if can't find a thing.

int fs_sexa	(	char *	out,
		double	a,
		int	w,
		int	fracbase
	)

Converts a sexagesimal number to a string.

sprint the variable a in sexagesimal format into out[].

Parameters:

	out	a pointer to store the sexagesimal number.
	a	the sexagesimal number to convert.
	w	the number of spaces in the whole part.
	fracbase	is the number of pieces a whole is to broken into; valid options: 360000: <w>:mm:ss.ss 36000: <w>:mm:ss.s 3600: <w>:mm:ss 600: <w>:mm.m 60: <w>:mm

Returns:

number of characters written to out, not counting final null terminator.

void getSexComponents	(	double	value,
		int *	d,
		int *	m,
		int *	s
	)

double JDtoGMST

(

double

jd

)

Return the degree, minute, and second components of a sexagesimal number.

Parameters:

	value	sexagesimal number to decompose.
	d	a pointer to double to store the degrees field.
	m	a pointer to a double to store the minutes field.
	s	a pointer to a double to store the seconds field. Converts Julian Date to Greenwich Sidereal Time.
	jd	The Julian date

Returns:

GMST in degrees

int numberFormat	(	char *	buf,
		const char *	format,
		double	value
	)

Fill buffer with properly formatted INumber string.

Parameters:

	buf	to store the formatted string.
	format	format in sprintf style.
	value	the number to format.

Returns:

length of string.

const char* timestamp

(

void

)

Create an ISO 8601 formatted time stamp.

The format is YYYY-MM-DDTHH:MM:SS

Returns:

The formatted time stamp.

double UTtoJD

(

struct tm *

utm

)

Converts Universal Time to Julian Date.

Parameters:

utm

a pointer to a structure holding the universal time and date.

Returns:

The Julian date fot the passed universal time.