NAME

       pmUnitsStr, pmUnitsStr_r - convert a performance metric's units into a string

C SYNOPSIS

       #include <pcp/pmapi.h>

       const char *pmUnitsStr(const pmUnits *pu);
       char *pmUnitsStr_r(const pmUnits *pu, char *buf, int buflen);

       cc ... -lpcp

DESCRIPTION

       The encoding of a performance metric's dimensionality and scale uses a pmUnits structure; see pmLookupDe‐
       sc(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, e.g.  count x 10^6.

       As a special case, if all components of the dimension are zero, then the ``count'' scale is used to  pro‐
       duce  the text.  If this scale is zero the result is an empty string, otherwise the result is of the form
       x1 0^2.

NOTES

       pmUnitsStr returns a pointer to a static buffer and hence is not  thread-safe.   Multi-threaded  applica‐
       tions should use pmUnitsStr_r instead.

SEE ALSO

       PMAPI(3),  pmAtomStr(3), pmConvScale(3), pmExtractValue(3), pmLookupDesc(3), pmPrintValue(3), pmIDStr(3),
       pmInDomStr(3), pmTypeStr(3), pmSemStr(3) and pmUnitsStr(3).

Performance Co-Pilot                                   PCP                                         PMUNITSSTR(3)