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authorLuca Falavigna <dktrkranz@debian.org>2010-01-02 20:31:23 +0100
committerLuca Falavigna <dktrkranz@debian.org>2010-01-02 20:31:23 +0100
commit9b73d2781acfc322319eb5c59b30f2dfa0fea977 (patch)
tree13c84e97c8ba1269d0943782dd195b70502736c9 /scons-time.1
parent3a672ee94aa5eeb0f1a10b044978c35b13077b67 (diff)
Imported Upstream version 1.2.0.d20091224upstream/1.2.0.d20091224
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+.\" Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+.\"
+.\" Permission is hereby granted, free of charge, to any person obtaining
+.\" a copy of this software and associated documentation files (the
+.\" "Software"), to deal in the Software without restriction, including
+.\" without limitation the rights to use, copy, modify, merge, publish,
+.\" distribute, sublicense, and/or sell copies of the Software, and to
+.\" permit persons to whom the Software is furnished to do so, subject to
+.\" the following conditions:
+.\"
+.\" The above copyright notice and this permission notice shall be included
+.\" in all copies or substantial portions of the Software.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+.\" KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+.\" WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+.\" NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+.\" LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+.\" OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+.\" WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+.\"
+.\" doc/man/scons-time.1 4577 2009/12/27 19:43:56 scons
+.\"
+.\" ES - Example Start - indents and turns off line fill
+.de ES
+.RS
+.nf
+..
+.\" EE - Example End - ends indent and turns line fill back on
+.de EE
+.RE
+.fi
+..
+'\"==========================================================================
+.de SF
+.B scons-time func
+[\fB-h\fR]
+[\fB--chdir=\fIDIR\fR]
+[\fB-f \fIFILE\fR]
+[\fB--fmt=\fIFORMAT\fR]
+[\fB--func=\fINAME\fR]
+[\fB-p \fISTRING\fR]
+[\fB-t \fINUMBER\fR]
+[\fB--title= TITLE\fR]
+[\fIARGUMENTS\fR]
+..
+'\"--------------------------------------------------------------------------
+.de SY
+.B scons-time mem
+[\fB-h\fR]
+[\fB--chdir=\fIDIR\fR]
+[\fB-f \fIFILE\fR]
+[\fB--fmt=\fIFORMAT\fR]
+[\fB-p \fISTRING\fR]
+[\fB--stage=\fISTAGE\fR]
+[\fB-t \fINUMBER\fR]
+[\fB--title=\fITITLE\fR]
+[\fIARGUMENTS\fR]
+..
+'\"--------------------------------------------------------------------------
+.de SO
+.B scons-time obj
+[\fB-h\fR]
+[\fB--chdir=\fIDIR\fR]
+[\fB-f \fIFILE\fR]
+[\fB--fmt=\fIFORMAT\fR]
+[\fB-p \fISTRING\fR]
+[\fB--stage=\fISTAGE\fR]
+[\fB-t \fINUMBER\fR]
+[\fB--title=\fITITLE\fR]
+[\fIARGUMENTS\fR]
+..
+'\"--------------------------------------------------------------------------
+.de SR
+.B scons-time run
+[\fB-hnqv\fR]
+[\fB--aegis=\fIPROJECT\fR]
+[\fB-f \fIFILE\fR]
+[\fB--number=\fINUMBER\fR]
+[\fB--outdir=\fIOUTDIR\fR]
+[\fB-p \fISTRING\fR]
+[\fB--python=\fIPYTHON\fR]
+[\fB-s \fIDIR\fR]
+[\fB--scons=\fISCONS\fR]
+[\fB--svn=\fIURL\fR]
+[\fIARGUMENTS\fR]
+..
+'\"--------------------------------------------------------------------------
+.de ST
+.B scons-time time
+[\fB-h\fR]
+[\fB--chdir=\fIDIR\fR]
+[\fB-f \fIFILE\fR]
+[\fB--fmt=\fIFORMAT\fR]
+[\fB-p \fISTRING\fR]
+[\fB-t \fINUMBER\fR]
+[\fB--title=\fITITLE\fR]
+[\fB--which=\fIWHICH\fR]
+[\fIARGUMENTS\fR]
+..
+.TH SCONS-TIME 1 "December 2009"
+.SH NAME
+scons-time \- generate and display SCons timing information
+'\"==========================================================================
+.SH SYNOPSIS
+.B scons-time
+.IR subcommand
+[
+.IR options ...
+]
+[
+.IR arguments ...
+]
+'\"--------------------------------------------------------------------------
+.SS "Generating Timing Information"
+.SR
+'\"--------------------------------------------------------------------------
+.SS "Extracting Function Timings"
+.SF
+'\"--------------------------------------------------------------------------
+.SS "Extracting Memory Statistics"
+.SY
+'\"--------------------------------------------------------------------------
+.SS "Extracting Object Counts"
+.SO
+'\"--------------------------------------------------------------------------
+.SS "Extracting Execution Times"
+.ST
+'\"--------------------------------------------------------------------------
+.SS "Help Text"
+.B scons-time help
+.I SUBCOMMAND
+[...]
+'\"==========================================================================
+.SH DESCRIPTION
+The
+.B scons-time
+command runs an SCons configuration
+through a standard set of profiled timings
+and can extract and graph information from the
+resulting profiles and log files of those timings.
+The action to be performed by the
+.B scons-time
+script is specified
+by a subcommand, the first argument on the command line.
+See the
+.B SUBCOMMANDS
+section below for information about the operation
+of specific subcommands.
+.P
+The basic way to use
+.B scons-time
+is to run the
+.B scons-time run
+subcommand
+(possibly multiple times)
+to generate profile and log file output,
+and then use one of the other
+subcommands to display the results
+captured in the profiles and log files
+for a particular kind of information:
+function timings
+(the
+.B scons-time func
+subcommand),
+total memory used
+(the
+.B scons-time mem
+subcommand),
+object counts
+(the
+.B scons-time obj
+subcommand)
+and overall execution time
+(the
+.B scons-time time
+subcommand).
+Options exist to place and find the
+profiles and log files in separate directories,
+to generate the output in a format suitable
+for graphing with the
+.BR gnuplot (1)
+program,
+and so on.
+.P
+There are two basic ways the
+.B scons-time run
+subcommand
+is intended to be used
+to gather timing statistics
+for a configuration.
+One is to use the
+.B --svn=
+option to test a configuration against
+a list of revisions from the SCons Subversion repository.
+This will generate a profile and timing log file
+for every revision listed with the
+.B --number=
+option,
+and can be used to look at the
+impact of commited changes to the
+SCons code base on a particular
+configuration over time.
+.P
+The other way is to profile incremental changes to a
+local SCons code base during a development cycle--that is,
+to look at the performance impact of changes
+you're making in the local tree.
+In this mode,
+you run the
+.B scons-time run
+subcommand
+.I without
+the
+.B --svn=
+option,
+in which case it simply looks in the profile/log file output directory
+(the current directory by default)
+and automatically figures out the
+.I next
+run number for the output profile and log file.
+Used in this way,
+the development cycle goes something like:
+make a change to SCons;
+run
+.B scons-time run
+to profile it against a specific configuration;
+make another change to SCons;
+run
+.B scons-time run
+again to profile it;
+etc.
+'\"==========================================================================
+.SH OPTIONS
+The
+.B scons-time
+command only supports a few global options:
+.TP
+-h, --help
+Displays the global help text and exits,
+identical to the
+.B scons-time help
+subcommand.
+.TP
+-V, --version
+Displays the
+.B scons-time
+version and exits.
+.P
+Most functionality is controlled by options
+to the individual subcommands.
+See the next section for information
+about individual subcommand options.
+'\"==========================================================================
+.SH SUBCOMMANDS
+The
+.B scons-time
+command supports the following
+individual subcommands.
+'\"--------------------------------------------------------------------------
+.SS "The func Subcommand"
+.SF
+.P
+The
+.B scons-time func
+subcommand displays timing information
+for a specific Python function within SCons.
+By default, it extracts information about the
+.BR _main ()
+function,
+which includes the Python profiler timing
+for all of SCons.
+.P
+The
+.B scons-time func
+subcommand extracts function timing information
+from all the specified file arguments,
+which should be Python profiler output files.
+(Normally, these would be
+.B *.prof
+files generated by the
+.B scons-time run
+subcommand,
+but they can actually be generated
+by any Python profiler invocation.)
+All file name arguments will be
+globbed for on-disk files.
+.P
+If no arguments are specified,
+then function timing information
+will be extracted from all
+.B *.prof
+files,
+or the subset of them
+with a prefix specified by the
+.B -p
+option.
+.P
+Options include:
+.TP
+-C DIRECTORY, --chdir=DIRECTORY
+Changes to the specified
+.I DIRECTORY
+before looking for the specified files
+(or files that match the specified patterns).
+.TP
+-f FILE, --file=FILE
+Reads configuration information from the specified
+.IR FILE .
+.TP
+-fmt=FORMAT, --format=FORMAT
+Reports the output in the specified
+.IR FORMAT .
+The formats currently supported are
+.B ascii
+(the default)
+and
+.BR gnuplot .
+.TP
+--func=NAME
+Extracts timings for the specified function
+.IR NAME .
+The default is to report cumulative timings for the
+.BR _main ()
+function,
+which contains the entire SCons run.
+.TP
+-h, --help
+Displays help text for the
+.B scons-time func
+subcommand.
+.TP
+-p STRING, --prefix=STRING
+Specifies the prefix string for profiles
+from which to extract function timing information.
+This will be used to search for profiles
+if no arguments are specified on the command line.
+.TP
+-t NUMBER, --tail=NUMBER
+Only extracts function timings from the last
+.I NUMBER
+files.
+'\"--------------------------------------------------------------------------
+.SS "The help Subcommand"
+.B scons-time help
+.I SUBCOMMAND
+[...]
+The
+.B help
+subcommand prints help text for any
+other subcommands listed as later arguments on the command line.
+'\"--------------------------------------------------------------------------
+.SS "The mem Subcommand"
+.SY
+.P
+The
+.B scons-time mem
+subcommand displays how much memory SCons uses.
+.P
+The
+.B scons-time mem
+subcommand extracts memory use information
+from all the specified file arguments,
+which should be files containing output from
+running SCons with the
+.B --debug=memory
+option.
+(Normally, these would be
+.B *.log
+files generated by the
+.B scons-time run
+subcommand.)
+All file name arguments will be
+globbed for on-disk files.
+.P
+If no arguments are specified,
+then memory information
+will be extracted from all
+.B *.log
+files,
+or the subset of them
+with a prefix specified by the
+.B -p
+option.
+.P
+.TP
+-C DIR, --chdir=DIR
+Changes to the specified
+.I DIRECTORY
+before looking for the specified files
+(or files that match the specified patterns).
+.TP
+-f FILE, --file=FILE
+Reads configuration information from the specified
+.IR FILE .
+.TP
+-fmt=FORMAT, --format=FORMAT
+Reports the output in the specified
+.IR FORMAT .
+The formats currently supported are
+.B ascii
+(the default)
+and
+.BR gnuplot .
+.TP
+-h, --help
+Displays help text for the
+.B scons-time mem
+subcommand.
+.TP
+-p STRING, --prefix=STRING
+Specifies the prefix string for log files
+from which to extract memory usage information.
+This will be used to search for log files
+if no arguments are specified on the command line.
+.TP
+--stage=STAGE
+Prints the memory used at the end of the specified
+.IR STAGE :
+.B pre-read
+(before the SConscript files are read),
+.B post-read ,
+(after the SConscript files are read),
+.B pre-build
+(before any targets are built)
+or
+.B post-build
+(after any targets are built).
+If no
+.B --stage
+option is specified,
+the default behavior is
+.BR post-build ,
+which reports the final amount of memory
+used by SCons during each run.
+.TP
+-t NUMBER, --tail=NUMBER
+Only reports memory statistics from the last
+.I NUMBER
+files.
+'\"--------------------------------------------------------------------------
+.SS "The obj Subcommand"
+.SO
+.P
+The
+.B scons-time obj
+subcommand displays how many objects of a specific named type
+are created by SCons.
+.P
+The
+.B scons-time obj
+subcommand extracts object counts
+from all the specified file arguments,
+which should be files containing output from
+running SCons with the
+.B --debug=count
+option.
+(Normally, these would be
+.B *.log
+files generated by the
+.B scons-time run
+subcommand.)
+All file name arguments will be
+globbed for on-disk files.
+.P
+If no arguments are specified,
+then object counts
+will be extracted from all
+.B *.log
+files,
+or the subset of them
+with a prefix specified by the
+.B -p
+option.
+.TP
+-C DIR, --chdir=DIR
+Changes to the specified
+.I DIRECTORY
+before looking for the specified files
+(or files that match the specified patterns).
+.TP
+-f FILE, --file=FILE
+Reads configuration information from the specified
+.IR FILE .
+.TP
+-fmt=FORMAT, --format=FORMAT
+Reports the output in the specified
+.IR FORMAT .
+The formats currently supported are
+.B ascii
+(the default)
+and
+.BR gnuplot .
+.TP
+-h, --help
+Displays help text for the
+.B scons-time obj
+subcommand.
+.TP
+-p STRING, --prefix=STRING
+Specifies the prefix string for log files
+from which to extract object counts.
+This will be used to search for log files
+if no arguments are specified on the command line.
+.TP
+--stage=STAGE
+Prints the object count at the end of the specified
+.IR STAGE :
+.B pre-read
+(before the SConscript files are read),
+.B post-read ,
+(after the SConscript files are read),
+.B pre-build
+(before any targets are built)
+or
+.B post-build
+(after any targets are built).
+If no
+.B --stage
+option is specified,
+the default behavior is
+.BR post-build ,
+which reports the final object count during each run.
+.TP
+-t NUMBER, --tail=NUMBER
+Only reports object counts from the last
+.I NUMBER
+files.
+'\"--------------------------------------------------------------------------
+.SS "The run Subcommand"
+.SR
+The
+.B scons-time run
+subcommand is the basic subcommand
+for profiling a specific configuration
+against a version of SCons.
+.P
+The configuration to be tested
+is specified as a list of files
+or directories that will be unpacked or copied
+into a temporary directory
+in which SCons will be invoked.
+The
+.B scons-time run
+subcommand understands file suffixes like
+.BR .tar ,
+.BR .tar.gz ,
+.BR .tgz
+and
+.BR .zip
+and will unpack their contents into a temporary directory.
+If more than one argument is specified,
+each one will be unpacked or copied
+into the temporary directory "on top of"
+the previous archives or directories,
+so the expectation is that multiple
+specified archives share the same directory layout.
+.P
+Once the file or directory arguments are unpacked or
+copied to the temporary directory,
+the
+.B scons-time run
+subcommand runs the
+requested version of SCons
+against the configuration
+three times:
+.TP
+Startup
+SCons is run with the
+.B --help
+option so that just the SConscript files are read,
+and then the default help text is printed.
+This profiles just the perceived "overhead" of starting up SCons
+and processing the SConscript files.
+.TP
+Full build
+SCons is run to build everything specified in the configuration.
+Specific targets to be passed in on the command l ine
+may be specified by the
+.B targets
+keyword in a configuration file; see below for details.
+.TP
+Rebuild
+SCons is run again on the same just-built directory.
+If the dependencies in the SCons configuration are correct,
+this should be an up-to-date, "do nothing" rebuild.
+.P
+Each invocation captures the output log file and a profile.
+.P
+The
+.B scons-time run
+subcommand supports the following options:
+.TP
+--aegis=PROJECT
+Specifies the Aegis
+.I PROJECT
+from which the
+version(s) of
+.B scons
+being timed will be extracted.
+When
+.B --aegis
+is specified, the
+.BI --number= NUMBER
+option specifies delta numbers
+that will be tested.
+Output from each invocation run will be placed in file
+names that match the Aegis delta numbers.
+If the
+.B --number=
+option is not specified,
+then the default behavior is to time the
+tip of the specified
+.IR PROJECT .
+.TP
+-f FILE, --file=FILE
+Reads configuration information from the specified
+.IR FILE .
+This often provides a more convenient way to specify and
+collect parameters associated with a specific timing configuration
+than specifying them on the command line.
+See the
+.B CONFIGURATION FILE
+section below
+for information about the configuration file parameters.
+.TP
+-h, --help
+Displays help text for the
+.B scons-time run
+subcommand.
+.TP
+-n, --no-exec
+Do not execute commands,
+just printing the command-line equivalents of what would be executed.
+Note that the
+.B scons-time
+script actually executes its actions in Python,
+where possible,
+for portability.
+The commands displayed are UNIX
+.I equivalents
+of what it's doing.
+.TP
+--number=NUMBER
+Specifies the run number to be used in the names of
+the log files and profile outputs generated by this run.
+.IP
+When used in conjuction with the
+.BI --aegis= PROJECT
+option,
+.I NUMBER
+specifies one or more comma-separated Aegis delta numbers
+that will be retrieved automatically from the specified Aegis
+.IR PROJECT .
+.IP
+When used in conjuction with the
+.BI --svn= URL
+option,
+.I NUMBER
+specifies one or more comma-separated Subversion revision numbers
+that will be retrieved automatically from the Subversion
+repository at the specified
+.IR URL .
+Ranges of delta or revision numbers
+may be specified be separating two numbers
+with a hyphen
+.RB ( \- ).
+.P
+Example:
+.ES
+% scons-time run --svn=http://scons.tigris.org/svn/trunk --num=1247,1249-1252 .
+.EE
+.TP
+-p STRING, --prefix=STRING
+Specifies the prefix string to be used for all of the log files
+and profiles generated by this run.
+The default is derived from the first
+specified argument:
+if the first argument is a directory,
+the default prefix is the name of the directory;
+if the first argument is an archive
+(tar or zip file),
+the default prefix is the the base name of the archive,
+that is, what remains after stripping the archive suffix
+.RB ( .tgz ", " .tar.gz " or " .zip ).
+.TP
+--python=PYTHON
+Specifies a path to the Python executable to be used
+for the timing runs.
+The default is to use the same Python executable that
+is running the
+.B scons-time
+command itself.
+.TP
+-q, --quiet
+Suppresses display of the command lines being executed.
+.TP
+-s DIR, --subdir=DIR
+Specifies the name of directory or subdirectory
+from which the commands should be executed.
+The default is XXX
+.TP
+--scons=SCONS
+Specifies a path to the SCons script to be used
+for the timing runs.
+The default is XXX
+.TP
+--svn=URL, --subversion=URL
+Specifies the
+.I URL
+of the Subversion repository from which the
+version(s) of
+.B scons
+being timed will be extracted.
+When
+.B --svn
+is specified, the
+.BI --number= NUMBER
+option specifies revision numbers
+that will be tested.
+Output from each invocation run will be placed in file
+names that match the Subversion revision numbers.
+If the
+.B --number=
+option is not specified,
+then the default behavior is to time the
+.B HEAD
+of the specified
+.IR URL .
+.TP
+-v, --verbose
+Displays the output from individual commands to the screen
+(in addition to capturing the output in log files).
+'\"--------------------------------------------------------------------------
+.SS "The time Subcommand"
+.ST
+.P
+The
+.B scons-time time
+subcommand displays SCons execution times
+as reported by the
+.B scons --debug=time
+option.
+.P
+The
+.B scons-time time
+subcommand extracts SCons timing
+from all the specified file arguments,
+which should be files containing output from
+running SCons with the
+.B --debug=time
+option.
+(Normally, these would be
+.B *.log
+files generated by the
+.B scons-time run
+subcommand.)
+All file name arguments will be
+globbed for on-disk files.
+.P
+If no arguments are specified,
+then execution timings
+will be extracted from all
+.B *.log
+files,
+or the subset of them
+with a prefix specified by the
+.B -p
+option.
+.TP
+-C DIR, --chdir=DIR
+Changes to the specified
+.I DIRECTORY
+before looking for the specified files
+(or files that match the specified patterns).
+.TP
+-f FILE, --file=FILE
+Reads configuration information from the specified
+.IR FILE .
+.TP
+-fmt=FORMAT, --format=FORMAT
+Reports the output in the specified
+.IR FORMAT .
+The formats currently supported are
+.B ascii
+(the default)
+and
+.BR gnuplot .
+.TP
+-h, --help
+Displays help text for the
+.B scons-time time
+subcommand.
+.TP
+-p STRING, --prefix=STRING
+Specifies the prefix string for log files
+from which to extract execution timings.
+This will be used to search for log files
+if no arguments are specified on the command line.
+.TP
+-t NUMBER, --tail=NUMBER
+Only reports object counts from the last
+.I NUMBER
+files.
+.TP
+--which=WHICH
+Prints the execution time for the specified
+.IR WHICH
+value:
+.B total
+(the total execution time),
+.B SConscripts
+(total execution time for the SConscript files themselves),
+.B SCons
+(exectuion time in SCons code itself)
+or
+.B commands
+(execution time of the commands and other actions
+used to build targets).
+If no
+.B --which
+option is specified,
+the default behavior is
+.BR total ,
+which reports the total execution time for each run.
+'\"==========================================================================
+.SH CONFIGURATION FILE
+Various
+.B scons-time
+subcommands can read information from a specified
+configuration file when passed the
+.B \-f
+or
+.B \--file
+options.
+The configuration file is actually executed as a Python script.
+Setting Python variables in the configuration file
+controls the behavior of the
+.B scons-time
+script more conveniently than having to specify
+command-line options or arguments for every run,
+and provides a handy way to "shrink-wrap"
+the necessary information for producing (and reporting)
+consistent timing runs for a given configuration.
+.TP
+.B aegis
+The Aegis executable for extracting deltas.
+The default is simply
+.BR aegis .
+.TP
+.B aegis_project
+The Aegis project from which deltas should be extracted.
+The default is whatever is specified
+with the
+.B --aegis=
+command-line option.
+.TP
+.B archive_list
+A list of archives (files or directories)
+that will be copied to the temporary directory
+in which SCons will be invoked.
+.BR .tar ,
+.BR .tar.gz ,
+.BR .tgz
+and
+.BR .zip
+files will have their contents unpacked in
+the temporary directory.
+Directory trees and files will be copied as-is.
+.TP
+.B initial_commands
+A list of commands that will be executed
+before the actual timed
+.B scons
+runs.
+This can be used for commands that are necessary
+to prepare the source tree\-for example,
+creating a configuration file
+that should not be part of the timed run.
+.TP
+.B key_location
+The location of the key on Gnuplot graphing information
+generated with the
+.BR --format=gnuplot
+option.
+The default is
+.BR "bottom left" .
+.TP
+.B prefix
+The file name prefix to be used when
+running or extracting timing for this configuration.
+.TP
+.B python
+The path name of the Python executable
+to be used when running or extracting information
+for this configuration.
+The default is the same version of Python
+used to run the SCons
+.TP
+.B scons
+The path name of the SCons script to be used
+when running or extracting information
+for this configuration.
+The default is simply
+.BR scons .
+.TP
+.B scons_flags
+The
+.B scons
+flags used when running SCons to collect timing information.
+The default value is
+.BR "--debug=count --debug=memory --debug=time --debug=memoizer" .
+.TP
+.B scons_lib_dir
+.TP
+.B scons_wrapper
+.TP
+.B startup_targets
+.TP
+.B subdir
+The subdirectory of the project into which the
+.B scons-time
+script should change
+before executing the SCons commands to time.
+.TP
+.B subversion_url
+The Subversion URL from
+.TP
+.B svn
+The subversion executable used to
+check out revisions of SCons to be timed.
+The default is simple
+.BR svn .
+.TP
+.B svn_co_flag
+.TP
+.B tar
+.TP
+.B targets
+A string containing the targets that should be added to
+the command line of every timed
+.B scons
+run.
+This can be used to restrict what's being timed to a
+subset of the full build for the configuration.
+.TP
+.B targets0
+.TP
+.B targets1
+.TP
+.B targets2
+.TP
+.B title
+.TP
+.B unzip
+.TP
+.B verbose
+.TP
+.B vertical_bars
+'\"--------------------------------------------------------------------------
+.SS Example
+Here is an example
+.B scons-time
+configuration file
+for a hypothetical sample project:
+.P
+.ES
+# The project doesn't use SCons natively (yet), so we're
+# timing a separate set of SConscript files that we lay
+# on top of the vanilla unpacked project tarball.
+arguments = ['project-1.2.tgz', 'project-SConscripts.tar']
+
+# The subdirectory name contains the project version number,
+# so tell scons-time to chdir there before building.
+subdir = 'project-1.2'
+
+# Set the prefix so output log files and profiles are named:
+# project-000-[012].{log,prof}
+# project-001-[012].{log,prof}
+# etc.
+prefix = 'project'
+
+# The SConscript files being tested don't do any SConf
+# configuration, so run their normal ./configure script
+# before we invoke SCons.
+initial_commands = [
+ './configure',
+]
+
+# Only time building the bin/project executable.
+targets = 'bin/project'
+
+# Time against SCons revisions of the branches/core branch
+subversion_url = 'http://scons.tigris.org/svn/scons/branches/core'
+.EE
+'\"==========================================================================
+.SH ENVIRONMENT
+The
+.B scons-time
+script uses the following environment variables:
+.TP
+.B PRESERVE
+If this value is set,
+the
+.B scons-time
+script will
+.I not
+remove the temporary directory or directories
+in which it builds the specified configuration
+or downloads a specific version of SCons.
+'\"==========================================================================
+.SH "SEE ALSO"
+.BR gnuplot (1),
+.BR scons (1)
+
+.SH AUTHORS
+Steven Knight <knight at baldmt dot com>