pmAtomStr,
pmAtomStr_r - convert a performance metric value into a
string
#include <pcp/pmapi.h>
const char *pmAtomStr(const pmAtomValue *
avp, int
type);
char *pmAtomStr_r(const pmAtomValue *
avp, int
type, char
*
buf, int
buflen);
cc ... -lpcp
All performance metric values may be encoded in a
pmAtomValue union,
defined as follows;
typedef union {
__int32_t l; /* 32-bit signed */
__uint32_t ul; /* 32-bit unsigned */
__int64_t ll; /* 64-bit signed */
__uint64_t ull; /* 64-bit unsigned */
float f; /* 32-bit floating point */
double d; /* 64-bit floating point */
char *cp; /* char ptr */
pmValueBlock *vbp; /* pmValueBlock ptr */
} pmAtomValue;
Given the performance metric value pointed to by
avp, and a performance
metric type defined by
type,
pmAtomStr will generate the
corresponding metric value as a string, suitable for diagnostic or report
output. The
pmAtomStr_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 80 bytes.
The value for
type is typically extracted from a
pmDesc structure,
following a call to
pmLookupDesc(3) for a particular performance
metric.
If the
type is
PM_TYPE_STRING values longer than 38 characters
will be truncated after 34 characters, and truncation shown with ellipsis
``...'' at the end of the value.
If the
type is
PM_TYPE_AGGREGATE then up to the first three 32-bit
words are displayed as hexadecimal values.
If the
type is
PM_TYPE_EVENT then a summary of the number of event
records found in the value is generated.
The return value from
pmAtomStr is held in a single static buffer, so the
returned value is only valid until the next call to
pmAtomStr.
pmAtomStr returns a pointer to a static buffer and hence is not
thread-safe. Multi-threaded applications should use
pmAtomStr_r
instead.
PMAPI(3),
pmConvScale(3),
pmExtractValue(3),
pmLookupDesc(3),
pmPrintValue(3),
pmTypeStr(3) and
pmUnitsStr(3).