Our work is published in Scientific Reports:

Ye, C. et al. DBG2OLC: Efficient Assembly of Large Genomes Using Long Erroneous Reads of the Third Generation Sequencing Technologies. Sci. Rep. 6, 31900; doi: 10.1038/srep31900 (2016).

http://www.nature.com/articles/srep31900

The manual can be downloaded from:

https://github.com/yechengxi/DBG2OLC/raw/master/Manual.docx

To use precompiled versions,please go to:

https://github.com/yechengxi/DBG2OLC/tree/master/compiled

Address of the bookmark: https://github.com/yechengxi/DBG2OLC

"The mathematical, statistical and computing methods that aim to solve biological problems using DNA and amino acid sequences and related information."

"The collection, organization and analysis of large amounts of biological data, using networks of computers and databases." - from the glossary for ABC Science Online's feature: The State of the Genome 2001.

"It is defined here as an interdisciplinary research area that applies computer and information science to solve biological problems. However, this is not the only definition. The field is being defined (and redefined) at present, and there are probably as many definitions as there are bioinformaticians (bioinformaticists?).

The following references are a snapshot of the moving target named bioinformatics. ... " - from the University of Minnesota Graduate Program in Bioinformatics' page: What is Bioinformatics,

"The application of computer technology to the management of biological information.Bioinformatics uses computers to solve problems in the life sciences, such as determination of DNA and protein sequences, investigation of protein functions, development of pharmaceuticals. It involves the creation of extensive electronic databases on genomes and protein sequences, and techniques such as the three-dimensional modeling of biomolecules and biologic systems. ..." - from the Bioinformatics Glossary edited by Charles E. Kahn, Jr., Medical College of Wisconsin.

"Bioinformatics is the field of science in which biology, computer science, and information technology merge to form a single discipline. The ultimate goal of the field is to enable the discovery of new biological insights as well as to create a global perspective from which unifying principles in biology can be discerned." - from the National Center for Biotechnology Information's Bioinformatics Factsheet.

"Research, development, or application of computational tools and approaches for expanding the use of biological, medical, behavioral or health data, including those to acquire, store, organize, archive, analyze, or visualize such data." - NIH Bioinformatics Web site

"The use of computers, laboratory robots and software to create, manage and interpret massive sets of complex biological data." - from the glossary for the University of Michigan Health System's Symphony of Life: Genetics & Medicine Web site.

"The field of science in which biology, computer science, and information technology merge into a single discipline.There are three important sub-disciplines within bioinformatics: (1) the development of new algorithms and statistics with which to assess relationships among members of large data sets; (2) the analysis and interpretation of various types of data including nucleotide and amino acid sequences, protein domains, and protein structures; and (3) the development and implementation of tools that enable efficient access and management of different types of information." - U.S. Environmental Protection Agency's ComputationalToxicology Research Glossary.

What is Bioinformatics? "One idea for a definition: (Molecular) Bio - informatics = is conceptualizing biology in terms of molecules (in the sense of physical-chemistry) and then applying "informatics" techniques (derived from disciplines such as applied math, CS, and statistics) to understand and organize the information associated with these molecules, on a large-scale." - By Mark Gerstein, Gerstein Group - Yale Bioinformatics.

Bioinformatics

Definition:

Bioinformatics derives knowledge from computer analysis of biological data. These can consist of the information stored in the genetic code, but also experimental results from various sources, patient statistics, and scientific literature. Research in bioinformatics includes method development for storage, retrieval, and analysis of the data. Bioinformatics is a rapidly developing branch of biology and is highly interdisciplinary, using techniques and concepts from informatics, statistics, mathematics, chemistry, biochemistry, physics, and linguistics. It has many practical applications in different areas of biology and medicine.

Description:

The history of computing in biology goes back to the 1920s when scientists were already thinking of establishing biological laws solely from data analysis by induction (e.g. A.J. Lotka, Elements of Physical Biology, 1925). However, only the development of powerful computers, and the availability of experimental data that can be readily treated by computation (for example, DNA or amino acid sequences and three–dimensional structures of proteins) launched bioinformatics as an independent field. Today, practical applications of bioinformatics are readily available through the world wide web, and are widely used in biological and medical research. As the field is rapidly evolving, the very definition of bioinformatics is still the matter of some debate.

The relationship between computer science and biology is a natural one for several reasons. First, the phenomenal rate of biological data being produced provides challenges: massive amounts of data have to be stored, analysed, and made accessible. Second, the nature of the data is often such that a statistical method, and hence computation, is necessary. This applies in particular to the information on the building plans of proteins and of the temporal and spatial organisation of their expression in the cell encoded by the DNA. Third, there is a strong analogy between the DNA sequence and a computer program (it can be shown that the DNA represents a Turing Machine).

Analyses in bioinformatics focus on three types of datasets: genome sequences, macromolecular structures, and functional genomics experiments (e.g. expression data, yeast two–hybrid screens). But bioinformatic analysis is also applied to various other data, e.g. taxonomy trees, relationship data from metabolic pathways, the text of scientific papers, and patient statistics. A large range of techniques are used, including primary sequence alignment, protein 3D structure alignment, phylogenetic tree construction, prediction and classification of protein structure, prediction of RNA structure, prediction of protein function, and expression data clustering. Algorithmic development is an important part of bioinformatics, and techniques and algorithms were specifically developed for the analysis of biological data (e.g., the dynamic programming algorithm for sequence alignment).

Bioinformatics has a large impact on biological research. Giant research projects such as the human genome project [4] would be meaningless without the bioinformatics component. The goal of sequencing projects, for example, is not to corroborate or refute a hypothesis, but to provide raw data for later analysis. Once the raw data are available, hypotheses may be formulated and tested in silico. In this manner, computer experiments may answer biological questions which cannot be tackled by traditional approaches. This has led to the founding of dedicated bioinformatics research groups as well as to a different work practice in the average bioscience laboratory where the computer has become an essential research tool.

Three key areas are the organisation of knowledge in databases, sequence analysis, and structural bioinformatics.

Organizing biological knowledge in databases:

Biological raw data are stored in public databanks (such as Genbank or EMBL for primary DNA sequences). The data can be submitted and accessed via the world wide web. Protein sequence databanks like trEMBL provide the most likely translation of all coding sequences in the EMBL databank. Sequence data are prominent, but also other data are stored, e. g. yeast two–hybrid screens, expression arrays, systematic gene–knock–out experiments, and metabolic pathways.

The stored data need to be accessed in a meaningful way, and often contents of several databanks or databases have to be accessed simultaneously and correlated with each other. Special languages have been developed to facilitate this task (such as the Sequence Retrieval System (SRS) and the Entrez system). An unsolved problem is the optimal design of inter–operating database systems. Databases provide additional functionality such as access to sequence homology searches and links to other databases and analysis results. For example, SWISSPROT [1] contains verified protein sequences and more annotations describing the function of a protein. Protein 3D structures are stored in specific databases (for example, the Protein Data Bank [2], now primarily curated and developed by the Research Collaboratory for Structural Bioinformatics). Organism specific databases have been developed (such as ACEDB, the A C. Elegans DataBase for the C. elegans genome, FLYBASE for D. melanogaster etc). A major problem are errors in databanks and databases (mostly errors in annotation), in particular since errors propagate easily through links.

Also databases of scientific literature (such as PUBMED, MEDLINE) provide additional functionality, e.g. they can search for similar articles based on word–usage analysis. Text recognition systems are being developed that extract automatically knowledge about protein function from the abstracts of scientific articles, notably on protein–protein interactions.

Analysing sequence data:

The primary data of sequencing projects are DNA sequences. These become only really valuable through their annotation. Several layers of analysis with bioinformatics tools are necessary to arrive from a raw DNA sequence at an annotated protein sequences:

• establish the correct order of sequence contigs to obtain one continuous sequence;
• find the tranlation and transcription initiation sites, find promoter sites, define open reading frames (ORF);
• find splice sites, introns, exons;
• translate the DNA sequence into a protein sequence, searching all six frames;
• compare the DNA sequence to known protein sequences in order to verify exons etc with homologuous sequences.

Some completely automated annotation systems have been developed (e.g., GENEQUIZ), which use a multitude of different programs and methods.

The protein sequences are further analysed to predict function. The function can often be inferred if a sequence of a homologous protein with known function can be found. Homology searches are the predominant bioinformatics application, and very efficient search methods have been developed [3]. The often difficult distinction between orthologous sequences and paralogous sequences facilitates the functional annotation in the comparison of whole genomes. Several methods detect glycolysation, myristylation and other sites, and the prediction of signal peptides in the amino acid sequence give valuable information about the subcellular location of a protein.

The ultimate goal of sequence annotation is to arrive at a complete functional description of all genes of an organism. However, function is an ill–defined concept. Thus, the simplified idea of “one gene – one protein – one structure – one function” cannot take into account proteins that have multiple functions depending on context (e.g., subcellar location and the presence of cofactors). Well-known cases of “moonlighting” proteins are lens crystalline and phosphoglucose isomerase. Currently, work on ontologies is under way to explicitly define a vocabulary that can be applied to all organisms even as knowledge of gene and protein roles in cells is accumulating and changing.

Families of similar sequences contain information on sequence evolution in the form of specific conservation patters at all sequence positions. Multiple sequence alignments are useful for

• building sequence profiles or Hidden Markov Models to perform more sensitive homology searches. A sequence profile contains information about the variability of every sequence position. improving structure prediction methods (secondary structure prediction). Sequence profile searches have become readily available through the introduction of PsiBLAST [3];
• studying evolutionary aspects, by the construction of phylogenetic trees from the pairwise differences between sequences: for example, the classification with 70S, 30S RNAs established the separate kingdom of archeae;
• determining active site residues, and residues specifc for subfamilies;
• predicting protein–protein interactions;
• analysing single nucleotide polymorphisms to hunt for genetic sources of deseases.
• Many complete genomes of microorganisms and a few of eukaryotes are available [4]. By analysis of entire genome sequences a wealth of additional information can be obtained. The complete genomic sequence contains not only all protein sequences but also sequences regulating gene expression. A comparison of the genomes of genetically close organisms reveals genes responsible for specific properties of the organisms (e.g., infectivity). Protein interactions can be predicted from conservation of gene order or operon organisation in different genomes. Also the detection of gene fusion and gene fission (i.e, one protein is split into two in another genome) events helps to deduce protein interactions.

Structural bioinformatics:

This branch of bioinformatics is concerned with computational approaches to predict and analyse the spatial structure of proteins and nucleic acids. Whereas in many cases the primary sequence uniquely specifies the three–dimensional (3D) structure, the specific rules are not well understood, and the protein folding problem remains largely unsolved. Some aspects of protein structure can already be predicted from amino acid content. Secondary structure can be deduced from the primary sequence with statistics or neural networks. When using a multiple sequence alignment, secondary structure can be predicted with an accuracy above 70 %.

3D models can be obtained most easily if the 3D structure of a homologous protein is known (homology modelling, comparative modelling). A homology model can only be as good as the sequence alignment: whereas protein relationships can be detected at the 20% identity level and below, a correct sequence alignment becomes very difficult, and the homology model will be doubtful. From 40 to 50% identity the models are usually mostly correct; however, it is possible to have 50% identity between two carefully designed protein sequences with different topology (the so –called JANUS protein). Remote relationships that are undetectable by sequence comparisons may be detected by sequence–to–structure–fitness (or threading) approaches: the search sequence is systematically compared to all known protein structures. Ab initio predictions of protein 3D structure remains the major challenge; some progress has been made recently by combining statistical with force–field based approaches.

Membrane proteins are interesting drug targets. It is estimated that membrane receptors form 50 % of all drug targets in pharmacological research. However, membrane proteins are underrepresented in the PDB structure database. Since membrane proteins are usually excluded from structural genomics initiatives due to technical problems, the prediction of transmembrane helices and solvent accessibility is very important. Modern methods can predict transmembrane helices with a reliability greater than 70 %.

Understanding the 3D structure of a macromolecule is crucial for understanding its function. Many properties of the 3D structure cannot be deduced directly from the primary sequence. Obtaining better understanding of protein function is the driving force behind structural genomics efforts, which can be thus understood as part of functional genomics. Similar structure can imply similar function. General structure–to–function relationships can be obtained by statistical approaches, for example, by relating secondary structure to known protein function or surface properties to cell location.

The increased speed of structure determination necessary for the structural genomics projects make an independent validation of the structures (by comparison to expected properties) particularly important. Structure validation helps to correct obvious errors (e.g., in the covalent structure) and leads to a more standardized representation of structural data, e.g., by agreeing on a common atom name nomenclature. The knowledge of the structure quality is a prerequisite for further use of the structure, e.g in molecular modelling or drug design.

In order to make as much data on the structure and its determination available in the databases, approaches for automated data harvesting are being developed. Structure classification schemes, as implemented for example in the SCOP, CATH, and FSSP databases, elucidate the relationship between protein folds and function and shed light on the evolution of protein domains.

Combined analysis of structural and genomic data will certainly get more important in the near future. Protein folds can be analysed for whole genomes. Protein–protein interactions predicted on the sequence level, can be studied in more detail on the structure level. Single Nucleotide Polymorphisms can be mapped on 3D structures of proteins in order to elucidate specific structural causes of disease.

More detailed aspects of protein function can be obtained also by force–field based approaches. Whereas protein function requires protein dynamics, no experimental technique can observe it directly on an atomic scale, and motions have to be simulated by molecular dynamics (MD) simulations. Also free energy differences (for example between binding energies of different protein ligands) can be characterized by MD simulations. Molecular mechanics or molecular dynamics based approaches are also necessary for homology modelling and for structure refinement in X–ray crystallography and NMR structure determination.

Drug design exploits the knowledge of the 3D structure of the binding site (or the structure of the complex with a ligand) to construct potential drugs, for example inhibitors of viral proteins or RNA. In addition to the 3D structure, a force field is necessary to evaluate the interaction between the protein and a ligand (to predict binding energies). In virtual screening, a library of molecules is tested on the computer for their capacities to bind to the macromolecule.

Pharmacological Relevance:

Many aspects of bioinformatics are relevant for pharmacology. Drug targets in infectious organisms can be revealed by whole genome comparisons of infectious and non–infectious organisms. The analysis of single nucleotide polymorphisms reveals genes potentially responsible for genetic deseases. Prediction and analysis of protein 3D structure is used to develop drugs and understand drug resistance.

Patient databases with genetic profiles, e.g. for cardiovascular diseases, diabetes, cancer, etc. may play an important role in the future for individual health care, by integrating personal genetic profile into diagnosis, despite obvious ethical problems. The goal is to analyse a patient’s individual genetic profile and compare it with a collection of reference profiles and other related information. This may improve individual diagnosis, prophylaxis, and therapy.

References:

Bairoch A, Apweiler R (2000) The SWISS–PROT protein sequence database and its supplement TrEMBL in 2000. Nucleic Acids Res. 28:45–48
Berman HM, Westbrook J, Feng Z, Gilliland G, Bhat TN, Weissig H, Shindyalov IN, Bourne PE (2000) The Protein Data Bank. Nucleic Acids Res. 28:235–42
Altschul SF, Madden TL, Schaffer AA, Zhang J, Zhang Z, Miller W, Lipman DJ (1997) Gapped BLAST and PSI–BLAST: a new generation of protein database search programs. Nucleic Acids Res. 25:3389–3402
Pearson WR (2000) Flexible sequence similarity searching with the FASTA3 program package. Methods Mol. Biol. 132:185–219
The Genome International Sequencing Consortium (2001) Initial sequencing and analysis of the human genome. Nature 409:860–921
JC Venter et al. (2001) The sequence of the human genome. Science 291:1304–1351
R.D. Fleischmann et al. (1995) Whole–genome random sequencing and assembly of haemophilus–influenzae. Science 269:496–51

https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/gkw377

Address of the bookmark: http://amp.pharm.mssm.edu/Enrichr/

1. TATA SCHOLARSHIP - Cornell University, New York State, USA
Tata, the Indian multinational conglomerate company, have a foundation known as the Tata Education & Development Trust which has endowed a multi million dollar sum to Cornell University to provide undergraduate scholarships to 20 Indian students every year.  In another example of supporting American universities, the Tata group also pledged US$50 million to Harvard University in recent years, whose executive management programme Ratan Tata attended in the 1970s.  Read more...  

2. BRADMAN FOUNDATION SCHOLARSHIP - University of Wollongong, Australia.
Named after Australia's cricket legend Donald Bradman, the UOW Bradman Foundation Scholarship was launched in 2012, with the help of Adam Gilchrist no less, to offer one successful Indian student each year a 50% reduction in tuition fees.  Read more...  

3. HUAWEI MAITREE SCHOLARSHIPS - Various Universities, China
Along with Tata, Huawei are the other huge corporation to be featured.  China's massive telecoms equipment vendor are involved in these scholarships offered to Indian students studying in China.  In 2013 there are 10 generous scholarships available which provide full tuition fees and living expenses.  The courses on which the scholarships are offered include Science and Technology courses, Social Sciences and Culture and Development courses.  Read more...

4. DR. MANMOHAN SINGH SCHOLARSHIPS - Cambridge University, England, UK
These scholarships have been designed to help budding Indian minds follow in the footsteps of Indian prime minister Manmohan Singh by studying at the prestigious Cambridge University.  The scholarships can be applied to any undergarduate course (with the two exceptions of medicine and veterinary science) and cover everything, i.e. tuition and college fees, living expenses and an additional grant to go towards travel expenses.  Read more...

5. OXFORD AND CAMBRIDGE SOCIETY OF INDIA - Oxford & Cambridge Universities, England, UK
As the name might suggest, these are scholarships available for students wishing to study at Oxford or Cambridge (cleverly known together as Oxbridge).  It is only available for applicants who are completing or have completed a degree at an Indian university, however these scholarships are for both undergraduate and graduate students.  Read more...

6. EDINBURGH NAPIER UNIVERSITY - Scotland, UK
This one applies to all countries in the Indian subcontinent and is for both undergraduate and graduate courses. Edinburgh Napier University offers a merit based discount of £2,000 Pounds.  Read more...

7. SHEFFIELD UNIVERSITY - Sheffield, UK
Provides merit-based scholarships for undergraduate and graduate programmes across all subjects. Read more...

8. INDIA 4EU II - Several Universities across Europe
Pioneered by the European Union and involving partner universities in France, Finland, Germany, Italy, Portugal, Spain and Sweden, the India 4EU II initiative is aimed at encouraging Indian students to study, work and live in Europe.  The initiative is well funded and allows the successful students tuition fees, expenses for living and travel costs as well as insurance during their time at one of the partner universities.  Read more...

9. TRINITY COLLEGE DUBLIN - Ireland
Valid for undergraduate courses in the faculties of Arts, Humanities, Social Sciences, Science, Computer Science or Engineering, the Trinity College Dublin offers Indian students scholarships to the tune of €9,000 per annum over a year degree course.  Read more...

10. UNIVERSITY COLLEGE DUBLIN - Ireland
Another of Ireland and Dublin's finest, the UCD awards one Global Excellence Undergraduate Scholarship which provides the worthy student a substantial 50% towards their tuition fees and is valid for all courses save medicine, radiography and veterinary medicine.  UCD also offers a Global Undergraduate Scholarship scheme for undergrads accepted on science, social sciences, arts and business courses.  This is all thanks to a €250,000 fund that will allow for 57 Indian students to benefit from scholarships at UCD.  Read more...

Applications are invited for the post of Project Assistant to work in the following
project.

• Title of the project: "A novel approach for the identification of key regulatory molecules and their pathways for Rheumatoid Arthritis" funded by Department of Science and Technology, New Delhi, Government of India.

• Project Assistant

• Essential Qualification: The minimum essential qualification would be M.Sc/B.Tech. in Bioinformatics/ Computer Science /Biotechnology.

• Salary : Rs. 8,000/month for a period of 3 years

Application in plain paper with following details: Name, Address, Date of Birth and Educational Qualifications and details of research experience with publications if any, may be sent to:

Mr. Sachidanand Singh,
Principal Investigator,
Department of Bioinformatics, School of Biotechnology and Health Sciences
Karunya University,
Karunya Nagar, Coimbatore- 641114

Ph.no: 09489677764, 09047654981

E-mail: sachidanand@karunya.edu

http://www.karunya.edu/bioinformatics/people/faculty/

Deadline : 25th August 2013

Advertisement: www.karunya.edu/bioinformatics/Project%20Assistant%20in%20SERB.pdf

For more information visit: http://www.snubi.org/TBC2013/

Address of the bookmark: https://www.igenbio.com/ergo/

http://www.interpretomics.co/

Perl's second wave of adoption came from the growth of the world wide web. Dynamic web pages—the precursor to modern web applications—were easy to create with Perl and CGI. Thanks to Perl's ubiquity as a language for system administrators and its power to manipulate text, it was the default choice for web programming. Its presence everywhere made it popular and, in some ways, the duct tape of the Internet.

Web Application Development

The old days of CGI programs and the simple development style that represented seem clunky. Web pages have become web applications. Development has moved from generating static HTML to both client and server side programming, with rich client interfaces and powerful backends.

Perl is still well suited for developing modern web apps. The language grows more powerful and easier to use every year, the available libraries are wonderful and keep getting better, and the inventions and discoveries available in modern Perl are unsurpassed.

In particular, a modern Perl developer can do amazing things with modern Perl tools. If you still think of Perl web development as a cgi-bin directory full of messy scripts that spew warnings to STDERR, you're a decade out of date. Better yet, you can replace that mess piecemeal, thanks to the new tools and techniques of modern Perl. See, for example, the ever-growing list of technologies Built in Perl.

Modern Perl Web Frameworks

While the old wave of web development may have made the CGI.pm module central, modern Perl web programming follows a stricter separation of business logic, URL and request routing, and output. The days of slinging a string here, an array there, a Perl hash yonder, declaring every variable at the top of the program, and maybe making a subroutine are gone. The Perl world has seen the value of abstraction and ways to mechanize away boilerplate. Perl has dozens of frameworks and toolkits designed to make web development and deployment simpler.

Any of a dozen of these frameworks will help you do great things, but three in particular stand out. You can build web sites and web applications of tremendous value with all three. These are neither the only good possibilities (think of POE or Jifty or Continuity or...) nor the only mechanisms for web programming with Perl (see Mechanize or LWP or Mojo::UserAgent for more). Yet if you want three good options to choose between, start here.

Catalyst

The Catalyst framework is a flexible and powerful system for building small to large web apps. It uses the Moose object system to provide great APIs for extension and further development. It's the most mature of the modern top Perl web frameworks, yet it retains its flexibility and vibrancy. In particular, its plugin and extension ecosystem allows it to evolve to provide new and essential features.

Catalyst has embraced the Plack/PSGI standard for Perl web deployment and recent versions are exploring high-scalability, event-based request handling models.

Dancer

The Dancer framework is deliberately minimal in syntax and scope, but it also has a vibrant plugin ecosystem. Dancer particularly excels for smaller sites and applications, though good programmers can build larger things with it.

The first version of Dancer was easy to use. Dancer 2 continues that ease while improving the internals and robustness of applications.

Mojolicious

The Mojolicious (Mojo) framework has a real-time design based on high performance event handling. Its focus is solving new and interesting problems in simple and effective ways, and the project has produced a lot of new code that does old things in better ways.

In particular, Mojolicious goes to great lengths to support new web standards, such as CSS 3, web sockets, and HTTP 2.

Where Catalyst embraces the CPAN fully, Mojolicious by design provides most of what an average app might need in a single download. It's still fully compatible with the CPAN, but the intention is to provide good working defaults in a package that's easy to start with. Mojo's fans are quick to praise it as fun to develop.

A modern Perl web developer should be familiar with at least one of these frameworks.

Modern Perl Storage Mechanisms

Perl's venerable DBI module has been the focal point of database access since its invention. Its design allows it to provide the same interface to huge relational databases and flat files alike through its DBD extension mechanism. Yet the DBI by itself isn't the be-all, end-all of data storage and access in Perl.

DBIx::Class

DBIx::Class sits on top of DBI to provide an API to your database based on the concept of queries and results. This is often sufficient to remove all but the most complicated of SQL from your code, leaving you to manipulate your business models instead of the small details of how a relational database works. The power and maintainability you receive is well the small cost of the learning curve.

Even better, DBIC can manage (and even generate) your database schema for you.

Recent versions of DBIC have demonstrated that a well-written ORM can perform much better than even clever hand-written code. Because it builds on the Perl DBI, it scales everywhere from SQLite to PostgreSQL, MySQL, Oracle, and more.

Rose::DB

The lesser-known but no less powerful Rose::DB::Object builds on Rose::DB to provide an object-relational mapper for Perl. While its high level features most directly compare to those of DBIx::Class, it's often measurably faster.

NoSQL on the CPAN

Of course the CPAN has modules for almost any NoSQL database or job queue or persistence mechanism you could name, and several you have never heard of. Everything you need is a quick CPAN or cpanm away!

Modern Perl Deployment Strategies

In the early days of the web, deploying a Perl web application meant putting one or more .cgi or .pl files in a special directory and hoping that your system administrator had everything configured correctly. The execution model was often slow and cumbersome, and accessing shared resources such as databases was often tricky.

Modern Perl has better choices. While deployment strategies are the source of many arguments, the return on your investment from learning the modern way is impressive.

Plack/PSGI

The PSGI specification (as exemplified by Plack) describes a strategy for building Perl web apps independent of server and with the possibility to share custom processing behaviors.

In other words, it's a standard for writing Perl apps to take advantage of the huge ecosystem of Perl development available on the CPAN without tying yourself to a server like Apache, Apache 2, nginx, or anything else.

Any good modern Perl web framework (including those listed here) supports PSGI. Several deployment mechanisms exist to meet various business needs which also support PSGI. In particular, you can deploy the same application with a local testing server on your own machine as you can to your production server or servers without changing your application at all.

mod_perl

The older but still viable mod_perl Apache httpd module embeds Perl into the web server. This was the first widespread persistence mechanism for Perl web applications themselves and it's still popular to this day, though PSGI compliance is often the choice for new development. (PSGI handlers to use mod_perl as the backend are available.)

Modern Perl developers should familiarize themselves with PSGI and the wealth of available Plack middleware.

Perl Web Development

Of course no discussion of Perl web development would be complete without mentioning the strength of the CPAN. Almost any project will benefit from the wealth of freely available libraries built to solve real problems. These distributions run the gamut from full-blown web frameworks and content management systems to APIs for web services, development tools, testing systems, and interfaces to document formats and external resources.

For example, if you need to write a web service which accepts JSON data and produces Excel spreadsheets, you can glue together a few CPAN distributions and get the job done early. If you need to consume XML from a remote service and emit a PDF, you're in luck.

Perl's prowess as a general purpose programming language as well as its flexibility and power in managing text and gluing systems together make it a wonderful fit for web development. The community's adoption of modern Perl standards such as PSGI and Plack only enhance your power.

Web application development in Perl is still viable, and modern Perl tools and techniques and libraries make it more powerful and pleasant than ever.

• File System
  ls — list items in current directory
  ls -l — list items in current directory and show in long format to see perimissions, size, and modification date
  ls -a — list all items in current directory, including hidden files
  ls -F — list all items in current directory and show directories with a slash and executables with a star
  ls dir — list all items in directory dir
  cd dir — change directory to dir
  cd .. — go up one directory
  cd / — go to the root directory
  cd ~ — go to to your home directory
  cd - — go to the last directory you were just in
  pwd — show present working directory
  mkdir dir — make directory dir
  rm file — remove file
  rm -r dir — remove directory dir recursively
  cp file1 file2 — copy file1 to file2
  cp -r dir1 dir2 — copy directory dir1 to dir2 recursively
  mv file1 file2 — move (rename) file1 to file2
  ln -s file link — create symbolic link to file
  touch file — create or update file
  cat file — output the contents of file
  less file — view file with page navigation
  head file — output the first 10 lines of file
  tail file — output the last 10 lines of file
  tail -f file — output the contents of file as it grows, starting with the last 10 lines
  vim file — edit file
  alias name 'command' — create an alias for a command
  
• System
  shutdown — shut down machine
  reboot — restart machine
  date — show the current date and time
  whoami — who you are logged in as
  finger user — display information about user
  man command — show the manual for command
  df — show disk usage
  du — show directory space usage
  free — show memory and swap usage
  whereis app — show possible locations of app
  which app — show which app will be run by default
  
• Process Management
  ps — display your currently active processes
  top — display all running processes
  kill pid — kill process id pid
  kill -9 pid — force kill process id pid
  
• Permissions
  ls -l — list items in current directory and show permissions
  chmod ugo file — change permissions of file to ugo - u is the user's permissions, g is the group's permissions, and o is everyone else's permissions. The values of u, g, and o can be any number between 0 and 7.
  7 — full permissions
  6 — read and write only
  5 — read and execute only
  4 — read only
  3 — write and execute only
  2 — write only
  1 — execute only
  0 — no permissions
  chmod 600 file — you can read and write - good for files
  chmod 700 file — you can read, write, and execute - good for scripts
  chmod 644 file — you can read and write, and everyone else can only read - good for web pages
  chmod 755 file — you can read, write, and execute, and everyone else can read and execute - good for programs that you want to share
  
• Networking
  wget file — download a file
  curl file — download a file
  scp user@host:file dir — secure copy a file from remote server to the dir directory on your machine
  scp file user@host:dir — secure copy a file from your machine to the dir directory on a remote server
  scp -r user@host:dir dir — secure copy the directory dir from remote server to the directory dir on your machine
  ssh user@host — connect to host as user
  ssh -p port user@host — connect to host on port as user
  ssh-copy-id user@host — add your key to host for user to enable a keyed or passwordless login
  ping host — ping host and output results
  whois domain — get information for domain
  dig domain — get DNS information for domain
  dig -x host — reverse lookup host
  lsof -i tcp:1337 — list all processes running on port 1337
  
• Searching
  grep pattern files — search for pattern in files
  grep -r pattern dir — search recursively for pattern in dir
  grep -rn pattern dir — search recursively for pattern in dir and show the line number found
  grep -r pattern dir --include='*.ext — search recursively for pattern in dir and only search in files with .ext extension
  command | grep pattern — search for pattern in the output of command
  find file — find all instances of file in real system
  locate file — find all instances of file using indexed database built from the updatedb command. Much faster than find
  sed -i 's/day/night/g' file — find all occurrences of day in a file and replace them with night - s means substitude and g means global - sed also supports regular expressions
  
• Compression
  tar cf file.tar files — create a tar named file.tar containing files
  tar xf file.tar — extract the files from file.tar
  tar czf file.tar.gz files — create a tar with Gzip compression
  tar xzf file.tar.gz — extract a tar using Gzip
  gzip file — compresses file and renames it to file.gz
  gzip -d file.gz — decompresses file.gz back to file
  
• Shortcuts
  ctrl+a — move cursor to beginning of line
  ctrl+f — move cursor to end of line
  alt+f — move cursor forward 1 word
  alt+b — move cursor backward 1 word