__pmParseHostSpec(3) uniform host specification parser

Other Alias



#include <pcp/pmapi.h>

int __pmParseHostSpec(const char *string, pmHostSpec **rsltp, int *count, char **errmsg)

void __pmFreeHostSpec(pmHostSpec *rslt, int count)

cc ... -lpcp


__pmParseHostSpec accepts a string specifying the location of a PCP performance metric collector daemon. The syntax of the various formats of this string is described in PCPIntro(1) where several examples are also presented.

The syntax allows the initial pmcd(1) hostname to be optionally followed by a list of port numbers, which will be tried in order when connecting to pmcd on that host. The portlist is separated from the hostname using a colon, and each port in the list is comma-separated.

In addition, one or more optional pmproxy(1) hosts can be specified (currently, only one proxy host is supported by the PCP protocols). These are separated from each other and from the pmcd component using the @ character. These may also be followed by an optional port list, using the same comma-separated syntax as before.

__pmParseHostSpec takes a null-terminated host specification string and returns an array of pmHostSpec structures, where the array has count entries.

These pmHostSpec structures that are returned via rsltp represent each individual host in the specification string and has the following declaration:

    typedef struct {
        char    *name;       /* hostname (always valid) */
        int     *ports;      /* array of host port numbers */
        int     nports;      /* number of ports in host port array */
    } pmHostSpec;

__pmParseHostSpec returns 0 if the given string was successfully parsed. In this case all the storage allocated by __pmParseHostSpec can be released by calling __pmFreeHostSpec using the address returned from __pmParseHostSpec via rsltp.

__pmParseHostSpec returns PM_ERR_GENERIC and a dynamically allocated error message string in errmsg, if the given string does not parse, and the user-supplied errmsg pointer is non-null. Be sure to free(3C) the error message string in this situation.

In the case of an error, rsltp is undefined. In the case of success, errmsg is undefined.