PMNUMBERSTR(3)

NAME
pmNumberStr, pmNumberStr_r - fixed width output format for numbers

C SYNOPSIS
#include <pcp/pmapi.h>

const char *pmNumberStr(double value);
char *pmNumberStr_r(double value, char *buf, int buflen);

cc ... -lpcp

DESCRIPTION
pmNumberStr returns the address of a 8-byte buffer that holds a null-byte terminated representation of value suitable for output with fixed width fields. The pmNumberStr_r function does the same, but stores the result in a user-supplied buffer buf of length buflen, which should have room for at least 8 bytes.

The value is scaled using multipliers in powers of ``one thousand'' (the decimal ``kilo'') and has a bias that provides greater precision for positive numbers as opposed to negative numbers.

The format depends on the sign and magnitude of value as follows (d represents a decimal digit):
value range | format
> 999995000000000 | inf?
999995000000000 - 999995000000 | ddd.ddT
999995000000 - 999995000 | ddd.ddG
999995000 - 999995 | ddd.ddM
999995 - 999.995 | ddd.ddK
999.995 - 0.005 | ddd.dd
0.005 - -0.005 | 0.00
-0.005 - -99.95 | -dd.dd
-99.995 - -99995 | -dd.ddK
-99995 - -99995000 | -dd.ddM
-99995000 - -99995000000 | -dd.ddG
-99995000000 - -99995000000000 | -dd.ddT
< -99995000000000 | -inf?

At the boundary points of the ranges, the chosen format will retain the maximum number of significant digits.

NOTES
pmNumberStr returns a pointer to a static buffer and hence is not thread-safe. Multi-threaded applications should use pmNumberStr_r instead.

SEE ALSO
printf(3)