pmUnitsStr,
pmUnitsStr_r - convert a performance metric's units into a
string
#include <pcp/pmapi.h>
const char *pmUnitsStr(const pmUnits *
pu);
char *pmUnitsStr_r(const pmUnits *
pu, char *
buf, int
buflen);
cc ... -lpcp
The encoding of a performance metric's dimensionality and scale uses a
pmUnits structure; see
pmLookupDesc(3).
As an aid to labeling graphs and tables, or for error messages,
pmUnitsStr will take a dimension and scale specification as per
pu, and return the corresponding text string. The
pmUnitsStr_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 60
bytes. If
buflen is less than 60 then
pmUnitsStr_r returns
NULL and
buf is not changed.
For example
{1, -2, 0, PM_SPACE_MBYTE, PM_TIME_SEC, 0}, as the value of
*pu gives the result string
Mbyte / sec^2.
The string value result from
pmUnitsStr is held in a single static
buffer, so the returned value is only valid until the next call to
pmUnitsStr.
If the ``count'' dimension is non-zero, and the ``count'' scale is not zero,
then the text string will include a decimal scaling factor, eg.
count x
10^6.
As a special case, if all components of the dimension are zero, then the
``count'' scale is used to produce the text. If this scale is zero the result
is an empty string, otherwise the result is of the form
x1 0^2.
pmUnitsStr returns a pointer to a static buffer and hence is not
thread-safe. Multi-threaded applications should use
pmUnitsStr_r
instead.
PMAPI(3),
pmAtomStr(3),
pmConvScale(3),
pmExtractValue(3),
pmLookupDesc(3),
pmPrintValue(3),
pmIDStr(3),
pmInDomStr(3),
pmTypeStr(3),
pmSemStr(3) and .