1PMPARSEUNITSSTR(3)         Library Functions Manual         PMPARSEUNITSSTR(3)
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NAME

6       pmParseUnitsStr - parse time point specification
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C SYNOPSIS

9       #include <pcp/pmapi.h>
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11       int pmParseUnitsStr(const char *string, struct pmUnits *out,
12               double *outMult, char **errMsg);
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14       cc ... -lpcp
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DESCRIPTION

17       pmParseUnitsStr is designed to  encapsulate  the  interpretation  of  a
18       unit/scale  specification  in  command line switches for use by the PCP
19       client tools.
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21       This function expects to be called with the unit/scale specification as
22       string.   This  specification  takes  the general form produced by pmU‐
23       nitsStr.  Briefly, the format allows /-separated divisor and  dividend,
24       each  listing  space-separated dimensions/scales along the space, time,
25       and count axes.  There are also a few extra possibilities:
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27       First, multiple equivalent sets of keywords are accepted for the time &
28       space  dimensions,  insensitive  to case.  For example, "microseconds",
29       "microsecond", "microsec",  "us"  are  considered  synonymous,  as  are
30       "kilobytes", "KB", "kiloByte", and so on.
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32       Second,  units may be offered in any order, e.g., ms kb count x 10^3 or
33       count x 10^3 kb ms.  They may not be repeated within the denominator or
34       within  the numerator.  Each scale/unit keyword may be immediately fol‐
35       lowed by positive or negative exponents, e.g., ^-4.
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37       Third, numerical scaling factors may be supplied.  These  are  factored
38       together with implicit scale conversions into the final outMult result.
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41       The  out  and  outMult values must both be allocated before calling pm‐
42       ParseUnitsStr.  If the conversion is  successful,  pmParseUnitsStr  re‐
43       turns  0,  and fills in out and outMult with the unit/scales defined by
44       the input parameter.  If the argument strings could not be  parsed,  it
45       returns a negative status code.
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EXAMPLES

49           ┌──────────────────────────────────┬────────────────┬─────────┐
50           │             string               │      out       │ outMult │
51           ├──────────────────────────────────┼────────────────┼─────────┤
52           │2 count                           │ {0,1,0,0,0,0}  │ 0.5     │
53           │count / 7.5 nanosecond            │ {0,1,-1,0,0,0} │ 7.5     │
54           │10 kilobytes / 2.5e2 count x 10^3 │ {1,-1,0,1,3,0} │ 25      │
55           │millisecond / second^2            │ {0,0,-1,0,0,3} │ 1000    │
56           │mb/s                              │ {1,0,-1,2,0,3} │ 1       │
57           └──────────────────────────────────┴────────────────┴─────────┘
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RETURN VALUE

60       A zero status indicates success.  A negative status indicates an error,
61       in which case the errMsg pointer will receive a textual error  message,
62       which the caller should later free().
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SEE ALSO

66       PMAPI(3), pmUnitsStr(3), pmConvScale(3), and pmLookupDesc(3).
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70Performance Co-Pilot                  PCP                   PMPARSEUNITSSTR(3)
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