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
Referenced By
The man pages pmnumberstr(3) and pmNumberStr_r(3) are aliases of pmNumberStr(3).