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NAME | C SYNOPSIS | DESCRIPTION | NOTES | SEE ALSO | COLOPHON |
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PMATOMSTR(3) Library Functions Manual PMATOMSTR(3)
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 per‐
formance 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 pmAtom‐
Str.
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).
This page is part of the PCP (Performance Co-Pilot) project. In‐
formation about the project can be found at ⟨http://www.pcp.io/⟩.
If you have a bug report for this manual page, send it to
pcp@groups.io. This page was obtained from the project's upstream
Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on
2025-08-11. (At that time, the date of the most recent commit
that was found in the repository was 2025-08-11.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a
mail to man-pages@man7.org
Performance Co-Pilot PCP PMATOMSTR(3)
Pages that refer to this page: pmconvscale(3), pmextractvalue(3), pmlookupdesc(3), pmprintvalue(3), pmsemstr(3), pmtypestr(3), pmunitsstr(3)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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