pmcpp (1) - Linux Manuals
pmcpp: simple preprocessor for the Performance Co-Pilot
NAME
pmcpp - simple preprocessor for the Performance Co-PilotSYNOPSIS
pmcpp [-Prs] [-D name[=value] ...] [-I dir ...] [infile]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:
to indicate the
following
line of output corresponds to line number
lineno
of the input file
filename.
The
-P
argument suppresses the generation of these linemarker lines.
The
-s
argument changes the expected input style from C-like to shell-like
(where # is a comment prefix). This forces the following changes
in
pmcpp
behaviour:
To provide finer control of macro expansion, the
-r
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:
For the following examples, the file
frequencies
contains the lines:
...
#endif
EXAMPLES
Command: pmcpp Input Output # 1 "<stdin>" #define MYDOMAIN 27 root { root {
foo 27:0:0 } }
%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 } } # 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 {
} %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 } } # 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 {
kernel.all.cpu.user
kernel.all.cpu.sys } } %endif 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).