table of contents
| PMNUMBERSTR(3) | Library Functions Manual | PMNUMBERSTR(3) |
NAME¶
pmNumberStr, pmNumberStr_r - fixed width output format for numbersC 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)| PCP | Performance Co-Pilot |