1PMDAGETOPTIONS(3) Library Functions Manual PMDAGETOPTIONS(3)
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6 pmdaGetOpt, pmdaGetOptions - get options from arguments, parsing
7 generic PMDA options
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10 #include <pcp/pmapi.h>
11 #include <pcp/pmda.h>
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13 int pmdaGetOptions(int argc, char *const *argv, pmdaOptions *opts,
14 pmdaInterface *dispatch);
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16 int pmdaGetOpt(int argc, char *const *argv, const char *optstring,
17 pmdaInterface *dispatch, int *err);
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19 cc ... -lpcp_pmda -lpcp
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22 These functions are wrappers for pmgetopt_r(3). The behavior of each
23 function is that certain options are assumed to have a predefined be‐
24 havior which initializes several fields in the pmdaInterface structure.
25 The pmdaGetOptions interface allows both short and long options to be
26 given, whereas pmdaGetOpt allows for short form options only.
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28 The options that both pmdaGetOptions and pmdaGetOpt will trap are:
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30 -Ddebugspec Set the PMAPI(3) debugging options to debugspec, as de‐
31 scribed in PCPIntro(1). Used for controlling levels of
32 trace output while debugging.
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34 -ddomain Set the domain number of this agent.
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36 -hhelpfile Obtain the help text (see pmdaText(3)) for the metrics
37 from this file rather than from the path specified with
38 pmdaDSO(3) or pmdaDaemon(3).
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40 -iport Expect PMCD to connect on inet port (number or name).
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42 -6port Expect PMCD to connect on ipv6 port (number or name).
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44 -llogfile Redirect diagnostics and trace output to logfile.
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46 -p Expect PMCD to supply stdin/stdout pipe.
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48 -usocket Expect PMCD to connect on unix domain socket.
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50 The pmdaGetOptions interface will also capture the following options,
51 and store them within the opts parameter:
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53 -Uusername Set the user account name under which the PMDA should
54 execute.
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56 Only one of -i, -6, -p and -u may be specified. If none of these three
57 options is given, a pipe (-p) is assumed. When these options are en‐
58 countered by pmdaGetOpt, the option is processed and the next option is
59 examined. Therefore, pmdaGetOpt will only return when an option other
60 than those listed above is found, or the end of the list is reached.
61 The returned value will be the argument or EOF, respectively.
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63 A PMDA can control which of these options the program will accept with
64 either the opts or optstring argument. To accept all the options, the
65 PMDA should call pmdaGetOptions with the short_options field of the
66 opts structure set to the PMDA_OPTIONS macro, or pmdaGetOpt with the
67 option string "D:d:h:i:l:pu:". Any PMDA specific options should be
68 added to these strings in the style of getopt(3), and will be returned
69 by both pmdaGetOptions and pmdaGetOpt if encountered.
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71 When a command line option usage error is detected in the pmdaGetOp‐
72 tions interface, the error field of the opts structure will contain a
73 non-zero error count.
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75 pmdaGetOpt takes a pointer to an int, err, which is used as an error
76 count. This variable should be initialized to zero before pmdaGetOpt
77 is first called, and tested when pmdaGetOpt returns EOF.
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79 Neither pmdaGetOptions nor pmdaGetOpt modify their argc or argv parame‐
80 ters.
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82 The global variables used by the system getopt (3) interface may also
83 be used by the caller of pmdaGetOpt within the argument parsing loop.
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85 On the other hand, the pmdaGetOptions interface does not utilize global
86 variables at all (neither reading nor modifying them). Instead, these
87 variables can be access via the opts fields of the same name.
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90 Both pmdaGetOptions and pmdaGetOpt will display the same error messages
91 as getopt.
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94 The options -D, -d, -i, -l, -p and -u cannot be reused for other pur‐
95 poses by the PMDA, unless using the override method provided by the
96 pmdaGetOptions interface, which operates in the same way as described
97 for the pmGetOptions(3) interface used by PMAPI client tools.
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99 The PMDA must be using PMDA_INTERFACE_2 or later, as specified in the
100 call to pmdaDSO(3) or pmdaDaemon(3).
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103 pmdbg(1), getopt(3), pmgetopt_r(3), pmGetOptions(3), PMAPI(3), PMDA(3),
104 pmdaDaemon(3), pmdaDSO(3) and pmdaText(3).
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108Performance Co-Pilot PCP PMDAGETOPTIONS(3)