1PMGETOPT(1) General Commands Manual PMGETOPT(1)
2
6 pmgetopt - Performance Co-Pilot shell script option parser
7
9 $PCP_BINADM_DIR/pmgetopt [-u?] [-c file] [-p name] [--] [parameters]
10
12 pmgetopt is used to perform command line option parsing for shell
13 scripts used in the Performance Co-Pilot (PCP toolkit). It is also
14 used to generate usage messages for those scripts.
15 The parameters given to pmgetopt take two forms: initially, options
17 specific to pmgetopt itself are passed in, and terminated using the --
18 mechanism. Thereafter, all of the parameters passed into the shell
19 script should be passed (usually this is simply the "$@" variable).
20
22 The options specific to pmgetopt are as follows:
23 -c=file, --config=file
25 A configuration file in the format described below is passed to
26 pmconfig using this option. If this option is omitted, then
27 pmconfig will read its configuration from the standard input
28 stream.
29 -p=name, --progname=name
31 When parsing the calling shell scripts parameters, error and usage
32 messages will contain the given program name rather than referring
33 to pmgetopt itself as the source of the error.
34 -u, --usage
36 A usage message appropriate for the calling shell script to
37 present as its own can be generated using the option.
38 -?, --help
40 Display the usage message for pmgetopt itself and exit.
41 pmgetopt parses the given parameters, and produces output in a format
43 suitable for sourcing in the calling shell script. When both short and
44 long forms of an argument are allowed by the specification, pmgetopt
45 will always indicate the short form for simpler shell processing. If
46 arguments are presented that do not match the configuration, a request
47 for a usage message (-?) will be generated for the calling script to
48 respond to. Any non-option parameters will be echoed back to the call‐
49 ing script preceded by the double-hyphen delimiter. Thus a script
50 should stop handling options when this delimiter is detected, and begin
51 the handling of any non-option arguments.
52 Unlike with the shell built-in getopt command, variables like $OPTARG
54 are not set and the calling script will typically employ use of the
55 shell built-in eval, set and positional shift commands to ensure option
56 processing occurs correctly.
57
59 The configuration format used by pmgetopt is intended to closely
60 reflect the usage message which would be generated in the presence of
61 invalid arguments (or the -?, --help option).
62 There are primarily two types of configuration line - commands and
64 options. Commands allow metadata to be passed into the option process‐
65 ing process, and options are the allowable command line options that
66 the shell script will accept. Command lines are preceded by the hash
67 character, whereas option lines will always begin with a hyphen (either
68 single or double). Any other line in the configuration, which may
69 include usage headers or descriptive text, has no impact on the option
70 parsing and will be copied unmodified into the usage message.
71 The set of commands is: getopt (provide short-argument option specifi‐
73 cation manually, if not present this will be generated from the options
74 presented), usage (provide short one-line summary used at the head of
75 the usage message, which will be prefixed by the progname before
76 reporting), and end which informs pmgetopt to stop processing further
77 commands and options - any subsequent text encountered will be simply
78 appended to the usage message.
79 A short-hand notation exists for each of the standard PCP options, as
81 described in PCPIntro(1). If any of these options (e.g --host) appears
82 as a single word on any line, it will be transformed into the appropri‐
83 ate option for the shell script, including all metadata about that
84 option (whether it accepts an argument, both short and long option
85 forms, and so on).
86 Use of the equals symbol ("=") indicates the presence of a required
88 argument to any option, for both short and long forms. Any non-stan‐
89 dard option must be accompanied by a non-empty description of that
90 argument.
91
93 As an example, the following is a valid configuration:
94 # Usage: [options] node...
96 Options:
98 --archive
99 -d, --delay pause between updates for archive replay
100 --host
101 --interval
102 -i=INST, --insts=INST comma-separated metrics instance list
103 -r output raw counters (no rate conversion)
104 --width=N set the width of each column of output
105 --timezone
106 --help
107 This configuration will produce the following usage message, when run
110 as shown.
111 $ pmgetopt --usage --progname=clusterstat -- "$@"
113 Usage: clusterstat [options] node...
114 Options:
116 -a FILE, --archive=FILE
117 metrics source is a PCP log archive
118 -d, --delay pause between updates for archive replay
119 -h HOST, --host=HOST metrics source is PMCD on host
120 -t DELTA, --interval=DELTA
121 sampling interval
122 -i INST, --insts=INST comma-separated metrics instance list
123 -r output raw counters (no rate conversion)
124 --width=N set the width of each column of output
125 -Z TZ, --timezone=TZ set reporting timezone
126 -?, --help show this usage message and exit
127 Several examples of pmgetopt use form part of the PCP toolkit, in par‐
130 ticular the pcp(1) and pmlogmv(1) scripts provide good reference exam‐
131 ples.
132
134 Environment variables with the prefix PCP_ are used to parameterize the
135 file and directory names used by PCP. On each installation, the file
136 /etc/pcp.conf contains the local values for these variables. The
137 $PCP_CONF variable may be used to specify an alternative configuration
138 file, as described in pcp.conf(5).
139
141 pcp(1), pmlogmv(1), pmgetopt_r(3), pcp.conf(5) and pcp.env(5).
142Performance Co-Pilot PCP PMGETOPT(1)