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| <!-- ##### DO NOT edit above this line unless you know what you are doing. ##### --> | | <!-- ##### DO NOT edit above this line unless you know what you are doing. ##### --> |
| ==Typical templates for Python scripts, C++ programs and others== | | ==About programming== |
|
| |
|
| It is always rewarding on the long term to start any piece of computer software with a minimum amount of generic code (verbose, command-line options, help message, license, etc). But it's a pain to write all this every time, right? So below are my typical templates for any Python script, C++ program, Beamer presentation, Bash script, etc.
| | * '''Resources''': most of the time, it's not necessary to buy a book, search online instead! |
| | ** [http://software-carpentry.org/ Software Carpentry] to learn about tests, versioning, Makefile, regular expressions, etc |
| | ** [http://www.cplusplus.com/doc/tutorial/ C++ tutorial], a must-read |
| | ** [http://scipy-lectures.github.io/ Python tutorial] for scientists |
|
| |
|
| * '''Easy user documentation''': I'm a firm believer that it is necessary to add some user documentation, even minimal, to any program. An easy way to do this is to simply generate such documentation from the "help" message, as long as it is "properly" formatted (see [http://www.gnu.org/s/help2man/ help2man]). The following commands work for any programming language: | | * '''Program templates''': it is always rewarding on the long term to start any piece of computer software with a minimum amount of generic code (command-line options, help message, license, usage of gzipped files, running time, etc). But it's a pain to write all this every time, right? And often we know how to do something in one language but not in another. So below are my typical templates for any C++/Python/R/Bash program, as well as Beamer presentation. |
| | ** '''C++''': download the file [http://github.com/timflutre/quantgen/blob/master/myprogram.cpp myprogram.cpp], as well as [http://github.com/timflutre/quantgen/blob/master/utils_io.cpp utils_io.cpp] along with its header [http://github.com/timflutre/quantgen/blob/master/utils_io.hpp utils_io.hpp]. |
| | ** '''Python''': download the file [http://github.com/timflutre/quantgen/blob/master/myprogram.py myprogram.py] |
| | ** '''R''': download the file [http://github.com/timflutre/quantgen/blob/master/myprogram.R myprogram.R] |
| | ** '''Bash''': download the file [http://github.com/timflutre/quantgen/blob/master/myprogram.bash myprogram.bash] |
| | |
| | * '''Language-independent user documentation''': I'm a firm believer that it is necessary to add some user documentation, even minimal, to any program. An easy way to do this is to simply generate such documentation from the "help" message, as long as it is "properly" formatted (see [http://www.gnu.org/s/help2man/ help2man]). The following commands work for any programming language: |
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| <nowiki> | | <nowiki> |
Line 17: |
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| groff -mandoc myprogram.man > myprogram.ps | | groff -mandoc myprogram.man > myprogram.ps |
| ps2pdf myprogram.ps myprogram.pdf | | ps2pdf myprogram.ps myprogram.pdf |
| </nowiki>
| |
|
| |
| * '''Python''': it is assumed that the code below is copied into a file named "MyClass.py".
| |
|
| |
| <nowiki>
| |
| #!/usr/bin/env python
| |
|
| |
| # Aim: does this and that
| |
| # choose between:
| |
| # Not copyrighted -- provided to the public domain
| |
| # or:
| |
| # Copyright (C) 2011-2013 Timothee Flutre
| |
| # License: GPLv3+
| |
|
| |
| import sys
| |
| import os
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| import getopt
| |
| import time
| |
| import datetime
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| import math
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|
| |
|
| |
| class MyClass(object):
| |
|
| |
| def __init__(self):
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| self.verbose = 1
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| self.input = ""
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|
| |
|
| |
| def help(self):
| |
| msg = "`%s' does this and that.\n" % os.path.basename(sys.argv[0])
| |
| msg += "\n"
| |
| msg += "Usage: %s [OPTIONS] ...\n" % os.path.basename(sys.argv[0])
| |
| msg += "\n"
| |
| msg += "Options:\n"
| |
| msg += " -h, --help\tdisplay the help and exit\n"
| |
| msg += " -V, --version\toutput version information and exit\n"
| |
| msg += " -v, --verbose\tverbosity level (0/default=1/2/3)\n"
| |
| msg += " -i\tinput"
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| msg += "\n"
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| msg += "Examples:\n"
| |
| print msg; sys.stdout.flush()
| |
|
| |
|
| |
| def version(self):
| |
| msg = "%s 1.0\n" % os.path.basename(sys.argv[0])
| |
| msg += "\n"
| |
| # choose between:
| |
| msg += "Not copyrighted -- provided to the public domain\n"
| |
| # or:
| |
| msg += "Copyright (C) 2011-2013 Timothee Flutre.\n"
| |
| msg += "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\n"
| |
| msg += "This is free software; see the source for copying conditions. There is NO\n"
| |
| msg += "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
| |
| msg += "\n"
| |
| msg += "Written by Timothee Flutre.\n"
| |
| print msg; sys.stdout.flush()
| |
|
| |
|
| |
| def setAttributesFromCmdLine(self):
| |
| try:
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| opts, args = getopt.getopt( sys.argv[1:], "hVv:i:",
| |
| ["help", "version", "verbose="])
| |
| except getopt.GetoptError, err:
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| sys.stderr.write("%s\n" % str(err))
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| self.help()
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| sys.exit(2)
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| for o, a in opts:
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| if o == "-h" or o == "--help":
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| self.help()
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| sys.exit(0)
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| elif o == "-V" or o == "--version":
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| self.version()
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| sys.exit(0)
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| elif o == "-v" or o == "--verbose":
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| self.verbose = int(a)
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| elif o == "-i":
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| self.input = a
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| else:
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| assert False, "unhandled option"
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|
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|
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| def checkAttributes(self):
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| if self.input == "":
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| msg = "ERROR: missing compulsory option -i"
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| sys.stderr.write("%s\n\n" % msg)
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| self.help()
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| sys.exit(1)
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| if not os.path.exists(self.input):
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| msg = "ERROR: can't find '%s'" % self.input
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| sys.stderr.write("%s\n\n" % msg)
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| self.help()
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| sys.exit(1)
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|
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|
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| def run(self):
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| self.checkAttributes()
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|
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| if self.verbose > 0:
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| msg = "START %s %s" % (os.path.basename(sys.argv[0]),
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| time.strftime("%Y-%m-%d %H:%M:%S"))
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| startTime = time.time()
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| print msg; sys.stdout.flush()
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|
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| # ... specific code ...
| |
|
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| if self.verbose > 0:
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| msg = "END %s %s" % (os.path.basename(sys.argv[0]),
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| time.strftime("%Y-%m-%d %H:%M:%S"))
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| endTime = time.time()
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| runLength = datetime.timedelta(seconds=
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| math.floor(endTime - startTime))
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| msg += " (%s)" % str(runLength)
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| print msg; sys.stdout.flush()
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|
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|
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| if __name__ == "__main__":
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| i = MyClass()
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| i.setAttributesFromCmdLine()
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| i.run()
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| </nowiki>
| |
|
| |
| * '''C++''': it is assumed that the code below is copied into a file named "myprogram.cpp" and that the file "[https://github.com/timflutre/quantgen/blob/master/utils.cpp utils.cpp]" is present in the same directory, along with the corresponding header <nowiki>utils.h</nowiki>.
| |
|
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| <nowiki>
| |
| /** \file myprogram.cpp
| |
| *
| |
| * `myprogram' does this and that.
| |
| * Copyright (C) 2011-2013 Timothee Flutre
| |
| *
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| * This program is free software: you can redistribute it and/or modify
| |
| * it under the terms of the GNU General Public License as published by
| |
| * the Free Software Foundation, either version 3 of the License, or
| |
| * (at your option) any later version.
| |
| *
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| * This program is distributed in the hope that it will be useful,
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| * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| * GNU General Public License for more details.
| |
| *
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| * You should have received a copy of the GNU General Public License
| |
| * along with this program. If not, see <http://www.gnu.org/licenses/>.
| |
| *
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| * g++ -Wall -g utils.cpp myprogram.cpp -lgsl -lgslcblas -lz -o myprogram
| |
| */
| |
|
| |
| #include <cmath>
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| #include <ctime>
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| #include <getopt.h>
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|
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| #include <iostream>
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| #include <string>
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| using namespace std;
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|
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| #include "utils.h"
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|
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| /** \brief Display the help on stdout.
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| */
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| void help (char ** argv)
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| {
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| cout << "`" << argv[0] << "'"
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| << " does this and that." << endl
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| << endl
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| << "Usage: " << argv[0] << " [OPTIONS] ..." << endl
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| << endl
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| << "Options:" << endl
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| << " -h, --help\tdisplay the help and exit" << endl
| |
| << " -V, --version\toutput version information and exit" << endl
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| << " -v, --verbose\tverbosity level (0/default=1/2/3)" << endl
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| << " -i, --in\tinput" << endl
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| << endl
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| << "Examples:" << endl
| |
| << " " << argv[0] << " -i <input>" << endl
| |
| << endl
| |
| << "Remarks:" << endl
| |
| << " This is my typical template file for C++." << endl
| |
| ;
| |
| }
| |
|
| |
| /** \brief Display version and license information on stdout.
| |
| */
| |
| void version (char ** argv)
| |
| {
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| cout << argv[0] << " 1.0" << endl
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| << endl
| |
| << "Copyright (C) 2011-2013 Timothee Flutre." << endl
| |
| << "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>" << endl
| |
| << "This is free software; see the source for copying conditions. There is NO" << endl
| |
| << "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE." << endl
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| << endl
| |
| << "Written by Timothee Flutre." << endl;
| |
| }
| |
|
| |
| /** \brief Parse the command-line arguments and check the values of the
| |
| * compulsory ones.
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| */
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| void
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| parseArgs (
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| int argc,
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| char ** argv,
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| string & input,
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| int & verbose)
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| {
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| int c = 0;
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| while (true)
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| {
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| static struct option long_options[] =
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| {
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| {"help", no_argument, 0, 'h'},
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| {"version", no_argument, 0, 'V'},
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| {"verbose", required_argument, 0, 'v'},
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| {"input", required_argument, 0, 'i'},
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| {0, 0, 0, 0}
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| };
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| int option_index = 0;
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| c = getopt_long (argc, argv, "hVv:i:",
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| long_options, &option_index);
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| if (c == -1)
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| break;
| |
| switch (c)
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| {
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| case 0:
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| if (long_options[option_index].flag != 0)
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| break;
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| case 'h':
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| help (argv);
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| exit (0);
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| case 'V':
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| version (argv);
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| exit (0);
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| case 'v':
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| verbose = atoi(optarg);
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| break;
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| case 'i':
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| input = optarg;
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| break;
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| case '?':
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| printf ("\n"); help (argv);
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| abort ();
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| default:
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| printf ("\n"); help (argv);
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| abort ();
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| }
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| }
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| if (input.empty())
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| {
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| printCmdLine (argc, argv);
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| fprintf (stderr, "ERROR: missing compulsory option -i\n\n");
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| help (argv);
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| exit (1);
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| }
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| if (! doesFileExist (input))
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| {
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| printCmdLine (argc, argv);
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| fprintf (stderr, "ERROR: can't find '%s'\n\n", input.c_str());
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| help (argv);
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| exit (1);
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| }
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| }
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|
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| int main (int argc, char ** argv)
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| {
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| string input;
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| int verbose = 1;
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|
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| parseArgs (argc, argv, input, verbose);
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|
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| time_t startRawTime, endRawTime;
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| if (verbose > 0)
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| {
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| time (&startRawTime);
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| cout << "START " << argv[0] << " (" << time2string (startRawTime) << ")"
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| << endl
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| << "compiled -> " << __DATE__ << " " << __TIME__
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| << endl << flush;
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| printCmdLine (argc, argv);
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| }
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|
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| // ... specific code ...
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|
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| if (verbose > 0)
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| {
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| time (&endRawTime);
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| cout << "END " << argv[0] << " (" << time2string (endRawTime) << ")"
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| << endl
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| << "elapsed -> " << elapsedTime(startRawTime, endRawTime)
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| << endl
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| << "max.mem -> " << getMaxMemUsedByProcess () << " kB"
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| << endl;
| |
| }
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|
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| return EXIT_SUCCESS;
| |
| }
| |
| </nowiki>
| |
|
| |
| * '''Bash''': sometimes it's easier to write a script in bash rather than in python. This is especially the case when one wants to use pipes, eg. <nowiki>zcat data.txt.gz | awk '{print $1}'</nowiki>, or when one wants to use a [http://en.wikipedia.org/wiki/Glob_%28programming%29 glob] to pass multiple files to the script, eg. <nowiki>./myscript.bash -i "input*.txt"</nowiki>.
| |
|
| |
| <nowiki>
| |
| #!/usr/bin/env bash
| |
|
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| # Aim: does this and that
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| # choose between:
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| # Not copyrighted -- provided to the public domain
| |
| # or:
| |
| # Copyright (C) 2011-2013 Timothee Flutre
| |
| # License: GPLv3+
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|
| |
| function help () {
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| msg="\`${0##*/}' does this and that.\n"
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| msg+="\n"
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| msg+="Usage: ${0##*/} [OPTIONS] ...\n"
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| msg+="\n"
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| msg+="Options:\n"
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| msg+=" -h, --help\tdisplay the help and exit\n"
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| msg+=" -V, --version\toutput version information and exit\n"
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| msg+=" -v, --verbose\tverbosity level (0/default=1/2/3)\n"
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| msg+=" -i, --in\tinput\n"
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| msg+="\n"
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| msg+="Examples:\n"
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| msg+=" $0 -i <input>\n"
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| echo -e "$msg"
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| }
| |
|
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| function version () {
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| msg="${0##*/} 1.0\n"
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| msg+="\n"
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| # choose between:
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| msg += "Not copyrighted -- provided to the public domain\n"
| |
| # or:
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| msg+="Copyright (C) 2011-2013 Timothee Flutre.\n"
| |
| msg+="License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\n"
| |
| msg+="This is free software; see the source for copying conditions. There is NO\n"
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| msg+="warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
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| msg+="\n"
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| msg+="Written by Timothee Flutre.\n"
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| echo -e "$msg"
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| }
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|
| |
| # source http://www.linuxjournal.com/content/use-date-command-measure-elapsed-time
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| function timer () {
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| if [[ $# -eq 0 ]]; then
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| echo $(date '+%s')
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| else
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| local stime=$1
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| etime=$(date '+%s')
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| if [[ -z "$stime" ]]; then stime=$etime; fi
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| dt=$((etime - stime))
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| ds=$((dt % 60))
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| dm=$(((dt / 60) % 60))
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| dh=$((dt / 3600))
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| printf '%d:%02d:%02d' $dh $dm $ds
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| fi
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| }
| |
|
| |
| function parseArgs () {
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| TEMP=`getopt -o hVv:i: -l help,version,verbose:,in: \
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| -n "$0" -- "$@"`
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| if [ $? != 0 ] ; then echo "ERROR: getopt failed" >&2 ; exit 1 ; fi
| |
| eval set -- "$TEMP"
| |
| while true; do
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| case "$1" in
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| -h|--help) help; exit 0; shift;;
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| -V|--version) version; exit 0; shift;;
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| -v|--verbose) verbose=$2; shift 2;;
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| -i|--in) input=$2; shift 2;;
| |
| --) shift; break;;
| |
| *) echo "ERROR: options parsing failed"; exit 1;;
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| esac
| |
| done
| |
| if [ -z "${input}" ]; then
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| echo "ERROR: missing compulsory option -i"; echo; help; exit 1
| |
| fi
| |
| if [ ! -f ${input} ]; then
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| echo "ERROR: can't find '${input}'"; exit 1
| |
| fi
| |
| }
| |
|
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| verbose=1
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| input=""
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| parseArgs "$@"
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|
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| if [ $verbose -gt "0" ]; then
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| printf "START ${0##*/} %s %s\n" $(date +"%Y-%m-%d") $(date +"%H:%M:%S")
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| startTime=$(timer)
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| fi
| |
|
| |
| # ... specific code ...
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|
| |
| if [ $verbose -gt "0" ]; then
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| printf "END ${0##*/} %s %s" $(date +"%Y-%m-%d") $(date +"%H:%M:%S")
| |
| printf " (%s)\n" $(timer startTime)
| |
| fi
| |
| </nowiki> | | </nowiki> |
|
| |
|