простой препроцессор для Performance Co-Pilot (simple preprocessor for the Performance Co-Pilot)
Имя (Name)
pmcpp
- simple preprocessor for the Performance Co-Pilot
Синопсис (Synopsis)
pmcpp
[-Prs?
] [-D
name[=value] ...] [-I
dir ...] [infile]
Описание (Description)
pmcpp
provides a very simple pre-processor originally designed
for manipulating Performance Metric Name Space (PMNS) files for
the Performance Co-Pilot (PCP), but later generalized to provide
conditional blocks, include file processing, in-line shell
command execution and macro substitution for arbitrary files. It
is most commonly used internally to process the PMNS file(s)
after pmLoadNameSpace(3) or pmLoadASCIINameSpace(3) is called and
to pre-process the configuration files for pmlogger(1).
Input lines are read from infile (or standard input if infile is
not specified), processed and written to standard output.
All C-style comments of the form /* ... */ are stripped from the
input stream.
There are no predefined macros for pmcpp
although macros may be
defined on the command line using the -D
option, where name and
value must follow the same rules as described below for the
#define
directive.
pmcpp
accepts the following directives in the input stream (like
cpp(1)):
• #include "
filename"
or
#include <
filename>
In either case the directory search path for filename tries
filename first, then the directory for the command line infile
(if any), followed by any directories named in -I
command line
arguments, and finally the $PCP_VAR_DIR/pmns
directory (the
latter is for backwards compatibility with earlier versions of
pmcpp
and the implied used from pmLoadASCIINameSpace(3)).
#include
directives may be nested, up to a maximum depth of 5.
• #shell "
command"
or
#shell '
command'
The shell
command will be executed and the standard output is
inserted into the stream of data to be processed by pmcpp
.
Functionally this is similar to a #include
directive, except
input lines are read from a command rather than a file. The
#shell
directive is most useful for including or excluding
#define
or #undef
directives based on run-time logic in the
command.
• #define
name value
or
#define
name "
value"
or
#define
name '
value'
Defines a value for the macro name which must be a valid C-
style name, so leading alphabetic or underscore followed by
zero or more alphanumerics or underscores. value is optional
(and defaults to an empty string). There is no character
escape mechanism, but either single quotes or double quotes
may be used to define a value with special characters or
embedded horizontal white space (no newlines).
• #undef
name
Removes the macro definition, if any, for name.
• #ifdef
name
...
#endif
or
#ifndef
name
...
#endif
The enclosing lines will be stripped or included, depending if
the macro name is defined or not.
• #else
Within a #ifdef
or #ifndef
block, #else
may be used to delimit
lines to be included if the preceding ``if'' condition is
false.
Macro substitution is achieved by breaking the input stream into
words separated by white space or characters that are not valid
in a macro name, i.e. not alphanumeric and not underscore. Each
word is checked and if it matches a macro name, the word is
replaced by the macro value, otherwise the word is unchanged.
There is generally one output line for each input line, although
the line may be empty if the text has been stripped due to the
handling of comments or conditional directives. When there is a
change in the input stream, an additional output line is
generated of the form:
# lineno "filename"
to indicate the following line of output corresponds to line
number lineno of the input file filename.
Параметры (Options)
The available command line options are:
-D
name[=value], --define
=name[=value]
Defines a macro with an optional value, as described
earlier.
-I
dir, --include
=dir
An additional directory to search for include files.
-P
Suppresses the generation of the linemarker lines, described
above.
-s
, --shell
Changes the expected input style from C-like to shell-like
(where # is a comment prefix). This forces the following
changes in pmcpp
behaviour:
• The control prefix character changes from #
to %
, so %include
for example.
• No comment stripping is performed.
-r
, --restrict
Provide finer control of macro expansion - this option
restricts macro substitution to words that match the patterns
#
name or #{
name}
or if -s
is specified, then %
name or %{
name}
.
In this mode, the macro name alone in the input stream will
never be expanded, however in control lines (like #ifdef
) the
macro name should appear alone with out the prefix character
or the curly braces (refer to the EXAMPLES below).
Important cpp(1) features that are not
supported by pmcpp
include:
• Macros with parameters - the pmcpp
macros support only
parameterless string substitution.
• #if
expr
...
#endif
• Nested use of #ifdef
or #ifndef
.
• Stripping C++ style comments, as in // comment.
• Error recovery - the first error encountered by pmcpp
will be
fatal.
• cpp(1) command line options like -o
, -W
, -U
, and -x
.
-?
, --help
Display usage message and exit.
Примеры (Examples)
┌─────────────────────────────────────────────┐
│Command: pmcpp
│
├───────────────────────┬─────────────────────┤
│Input
│ Output
│
├───────────────────────┼─────────────────────┤
│ │ # 1 "<stdin>" │
│#define MYDOMAIN 27 │ │
│ │ │
│root { │ root { │
│ foo MYDOMAIN:0:0 │ foo 27:0:0 │
│} │ } │
└───────────────────────┴─────────────────────┘
For the following examples, the file frequencies contains the
lines:
%define dk_freq 1minute
%define cpu_freq '15 sec'
┌──────────────────────────────────────────────────────────────────────┐
│Command: pmcpp -rs
│
├──────────────────────────────────┬───────────────────────────────────┤
│Input
│ Output
│
├──────────────────────────────────┼───────────────────────────────────┤
│# get logging frequencies │ # get logging frequencies │
│# e.g. dk_freq macro │ # e.g. dk_freq macro │
│%include "frequencies" │ │
│ │ │
│log mandatory on %dk_freq { │ log mandatory on 1minute { │
│ disk.dev │ disk.dev │
│} │ } │
│ │ │
│# note no % for want_cpu here │ # note no % for want_cpu here │
│%ifdef want_cpu │ │
│%define cpu_pfx 'kernel.all.cpu.' │ │
│log mandatory on %cpu_freq { │ │
│ %{cpu_pfx}user │ │
│ %{cpu_pfx}sys │ │
│} │ │
│%endif │ │
└──────────────────────────────────┴───────────────────────────────────┘
┌──────────────────────────────────────────────────────────────────────┐
│Command: pmcpp -rs -Dwant_cpu
│
├──────────────────────────────────┬───────────────────────────────────┤
│Input
│ Output
│
├──────────────────────────────────┼───────────────────────────────────┤
│# get logging frequencies │ # get logging frequencies │
│# e.g. dk_freq macro │ # e.g. dk_freq macro │
│%include "frequencies" │ │
│ │ │
│log mandatory on %dk_freq { │ log mandatory on 1minute { │
│ disk.dev │ disk.dev │
│} │ } │
│ │ │
│# note no % for want_cpu here │ # note no % for want_cpu here │
│%ifdef want_cpu │ │
│%define cpu_pfx 'kernel.all.cpu.' │ │
│log mandatory on %cpu_freq { │ log mandatory on 15 sec { │
│ %{cpu_pfx}user │ kernel.all.cpu.user │
│ %{cpu_pfx}sys │ kernel.all.cpu.sys │
│} │ } │
│%endif │ │
└──────────────────────────────────┴───────────────────────────────────┘
Окружение PCP (PCP environment)
Environment variables with the prefix PCP_
are used to
parameterize the file and directory names used by PCP. On each
installation, the file /etc/pcp.conf contains the local values
for these variables. The $PCP_CONF
variable may be used to
specify an alternative configuration file, as described in
pcp.conf(5).
For environment variables affecting PCP tools, see
pmGetOptions(3).
Смотри также (See also)
cpp(1), pmLoadASCIINameSpace(3), pmLoadNameSpace(3), pcp.conf(5),
pcp.env(5) and PMNS(5).