Linux Certif

Toute la documentation sur la certification Linux LPI

mmv_lookup_value_desc

NAME

mmv_lookup_value_desc - find a value in the Memory Mapped Value file

C SYNOPSIS

#include <pcp/pmapi.h> #include <pcp/mmv_stats.h>

 pmAtomValue * 
 mmv_lookup_value_desc(void *addr, const char *metric, const char *inst);
 

cc ... -lpcp_mmv -lpcp

DESCRIPTION

mmv_lookup_value_desc searches for the value of the instance identified by the external instance name inst of the metric metric in the MMV(4) file. addr is the address returned from mmv_stats_init(). The pointer returned points to a pmAtomValue union, which is 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;
 

MMV string values should be set using either of the mmv_set_string or mmv_set_strlen routines.

RETURNS

The function returns the address inside of the memory mapped region on success or NULL on failure.

SEE ALSO

mmv_stats_init(3), mmv_inc_value(3) and BR mmv (4).