pmParseUnitsStr (3) - Linux Manuals
pmParseUnitsStr: parse time point specification
NAME
pmParseUnitsStr - parse time point specificationC SYNOPSIS
#include <pcp/pmapi.h>
This function expects to be called with the unit/scale specification as
string.
This specification takes the general form produced by
pmUnitsStr.
Briefly, the format allows /-separated divisor and dividend, each
listing space-separated dimensions/scales along the space, time, and count
axes. There are also a few extra possibilities:
First, multiple equivalent sets of keywords are accepted for the time
& space dimensions, insensitive to case. For example, "microseconds",
"microsecond", "microsec", "us" are considered synonymous, as are
"kilobytes", "KB", "kiloByte", and so on.
Second, units may be offered in any order, e.g., ms kb count x 10^3 or
count x 10^3 kb ms. They may not be repeated within the denominator
or within the numerator. Each scale/unit keyword may be immediately followed
by positive or negative exponents, e.g., ^-4.
Third, numerical scaling factors may be supplied. These are factored
together with implicit scale conversions into the final outMult result.
The
out and outMult
values must both be allocated before calling
pmParseUnitsStr.
If the conversion is successful,
pmParseUnitsStr
returns 0, and fills in
out and outMult
with the unit/scales defined by the input
parameter. If the argument strings could not be parsed, it returns a negative status code.
int pmParseUnitsStr(const char *string, struct pmUnits DESCRIPTION
pmParseUnitsStr
is designed to encapsulate the interpretation of a unit/scale specification in
command line switches for use by the PCP client tools.
EXAMPLES
string out outMult 2 count {0,1,0,0,0,0} 0.5 count / 7.5 nanosecond {0,1,-1,0,0,0} 7.5 10 kilobytes / 2.5e2 count x 10^3 {1,-1,0,1,3,0} 25 millisecond / second^2 {0,0,-1,0,0,3} 1000 mb/s {1,0,-1,2,0,3} 1 RETURN VALUE
A zero status indicates success. A negative status indicates
an error, in which case the errMsg pointer will receive a textual
error message, which the caller should later free().