pmAtomStr(3) convert a performance metric value into a string


#include <pcp/pmapi.h>

const char *pmAtomStr(const pmAtomValue *avp, int type)

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 */
    void         *vp;   /* void ptr */
} pmAtomValue;

Given the performance metric value pointed to by avp, and a performance metric type defined by type, generate the corresponding metric value as a string, suitable for diagnostic or report output.

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 only the first three 32-bit words are displayed as hexadecimal values.

The string value is held in a single static buffer, so the returned value is only valid until the next call to pmAtomStr.