'\"macro stdmacro
.\"
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.TH PMATOMSTR 3 "PCP" "Performance Co-Pilot"
.SH NAME
\f3pmAtomStr\f1,
\f3pmAtomStr_r\f1 \- convert a performance metric value into a string
.SH "C SYNOPSIS"
.ft 3
#include <pcp/pmapi.h>
.sp
const char *pmAtomStr(const pmAtomValue *\fIavp\fP, int \fItype\fP);
.br
char *pmAtomStr_r(const pmAtomValue *\fIavp\fP, int \fItype\fP, char *\fIbuf\fP, int \fIbuflen\fP);
.sp
cc ... \-lpcp
.ft 1
.SH DESCRIPTION
.de CR
.ie t \f(CR\\$1\f1\\$2
.el \fI\\$1\f1\\$2
..
All performance metric values may be encoded in a
.CR pmAtomValue
union, defined as follows;
.PP
.ft CR
.nf
.in +0.5i
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;
.in
.fi
.ft 1
.PP
Given the performance metric value pointed to by
.IR avp ,
and a performance metric type defined by
.IR type ,
.B pmAtomStr
will generate the corresponding metric value as a string,
suitable for diagnostic or report output.
The
.B pmAtomStr_r
function does the same, but stores the result in a user-supplied buffer
.I buf
of length
.IR buflen ,
which should have room for at least 80 bytes.
.PP
The value for
.I type
is typically extracted from a
.CR pmDesc
structure, following a call to
.BR pmLookupDesc (3)
for a particular performance metric.
.PP
If the
.I type
is
.B 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.
.PP
If the
.I type
is
.B PM_TYPE_AGGREGATE
then up to the first three 32-bit words are displayed as hexadecimal values.
.PP
If the
.I type
is
.B PM_TYPE_EVENT
then a summary of the number of event records found in the value
is generated.
.PP
The return value from
.B pmAtomStr
is held in a single static buffer, so
the returned value is only valid until the next call
to
.BR pmAtomStr .
.SH NOTES
.B pmAtomStr
returns a pointer to a static buffer and hence is not thread-safe.
Multi-threaded applications should use
.B pmAtomStr_r
instead.
.SH SEE ALSO
.BR PMAPI (3),
.BR pmConvScale (3),
.BR pmExtractValue (3),
.BR pmLookupDesc (3),
.BR pmPrintValue (3),
.BR pmTypeStr (3)
and
.BR pmUnitsStr (3).

.\" control lines for scripts/man-spell
.\" +ok+ vbp ull ptr ll ul