PMATOMSTR

Section: C Library Functions (3)
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NAME

pmAtomStr , pmAtomStr_r - convert a performance metric value into a string

C SYNOPSIS

#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

DESCRIPTION

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 .

NOTES

pmAtomStr returns a pointer to a static buffer and hence is not thread-safe. Multi-threaded applications should use pmAtomStr_r instead.

SEE ALSO

PMAPI (3), pmConvScale (3), pmExtractValue (3), pmLookupDesc (3), pmPrintValue (3), pmTypeStr (3) and pmUnitsStr (3).


Index

NAME
C SYNOPSIS
DESCRIPTION
NOTES
SEE ALSO