grops(1)


NAME

   grops - PostScript driver for groff

SYNOPSIS

   grops [-glmv] [-b n] [-c n] [-F dir] [-I dir] [-p papersize]
         [-P prologue] [-w n] [files ...]

DESCRIPTION

   grops translates the output of GNU troff to PostScript.  Normally grops
   should  be  invoked  by  using  the  groff  command with a -Tps option.
   (Actually, this is the default for groff.)   If  no  files  are  given,
   grops  reads  the standard input.  A filename of - also causes grops to
   read the standard input.  PostScript output is written to the  standard
   output.   When  grops  is  run  by groff options can be passed to grops
   using groff's -P option.

   Note that grops doesn't produce a valid document structure  (conforming
   to  the  Document  Structuring Convention) if called with multiple file
   arguments.  To print  such  concatenated  output  it  is  necessary  to
   deactivate  DSC  handling  in  the  printing program or previewer.  See
   section FONT INSTALLATION below for a guide how to  install  fonts  for
   grops.

OPTIONS

   It is possible to have whitespace between a command line option and its
   parameter.

   -bn    Provide workarounds for older  printers,  broken  spoolers,  and
          previewers.    Normally  grops  produces  output  at  PostScript
          LanguageLevel  2  that  conforms  to  the  Document  Structuring
          Conventions  version  3.0.   Some  older printers, spoolers, and
          previewers can't handle such output.  The value  of  n  controls
          what  grops does to make its output acceptable to such programs.
          A value of 0 causes grops not to employ any workarounds.

          Add 1 if no %%BeginDocumentSetup and %%EndDocumentSetup comments
          should  be  generated;  this  is  needed  for  early versions of
          TranScript that get confused by anything between the %%EndProlog
          comment and the first %%Page comment.

          Add  2  if  lines  in included files beginning with %! should be
          stripped out; this is needed for Sun's pageview previewer.

          Add 4 if %%Page, %%Trailer and %%EndProlog  comments  should  be
          stripped out of included files; this is needed for spoolers that
          don't understand the %%BeginDocument and %%EndDocument comments.

          Add 8 if the first line of the PostScript output should be %!PS-
          Adobe-2.0  rather than %!PS-Adobe-3.0; this is needed when using
          Sun's Newsprint with a printer that requires page reversal.

          Add 16 if no media size information should be  included  in  the
          document   (this   is,   neither  use  %%DocumentMedia  nor  the
          setpagedevice PostScript command).  This was  the  behaviour  of
          groff  version  1.18.1  and  earlier;  it  is  needed  for older
          printers which don't understand PostScript LanguageLevel 2.   It
          is  also  necessary if the output is further processed to get an
          encapsulated PS (EPS) file -- see below.

          The default value can be specified by a

                 broken n

          command in the DESC file.  Otherwise the default value is 0.

   -cn    Print n copies of each page.

   -Fdir  Prepend directory dir/devname to the search path  for  prologue,
          font,  and  device  description  files;  name is the name of the
          device, usually ps.

   -g     Guess the page length.   This  generates  PostScript  code  that
          guesses  the  page  length.   The  guess  is correct only if the
          imageable area is vertically centered on the page.  This  option
          allows  you  to  generate  documents that can be printed both on
          letter (8.511) paper and on A4 paper without change.

   -Idir  This option may be used to add a directory to  the  search  path
          for  files on the command line and files named in \X'ps: import'
          and \X'ps: file' escapes.  The search path is  initialized  with
          the  current  directory.  This option may be specified more than
          once; the directories are then searched in the  order  specified
          (but  before  the  current  directory).  If you want to make the
          current directory be read before other directories, add  -I.  at
          the appropriate place.

          No directory search is performed for files with an absolute file
          name.

   -l     Print the document in landscape format.

   -m     Turn manual feed on for the document.

   -ppaper-size
          Set physical dimension of output  medium.   This  overrides  the
          papersize,  paperlength,  and  paperwidth  commands  in the DESC
          file; it accepts the same arguments as  the  papersize  command.
          See groff_font (5) for details.

   -Pprologue-file
          Use  the  file  prologue-file (in the font path) as the prologue
          instead of the default  prologue  file  prologue.   This  option
          overrides the environment variable GROPS_PROLOGUE.

   -wn    Lines  should  be drawn using a thickness of n thousandths of an
          em.  If this option is not given, the line thickness defaults to
          0.04 em.

   -v     Print the version number.

USAGE

   The  input  to grops must be in the format output by troff(1).  This is
   described in groff_out(5).

   In addition, the device and font description files for the device  used
   must  meet  certain  requirements:  The  resolution  must be an integer
   multiple of 72 times the sizescale.  The ps device uses a resolution of
   72000 and a sizescale of 1000.

   The  device  description  file  must  contain  a  valid paper size; see
   groff_font(5) for more information.

   Each font description file must contain a command

          internalname psname

   which says that the PostScript name of the font is psname.  It may also
   contain a command

          encoding enc_file

   which  says  that  the  PostScript  font  should be reencoded using the
   encoding described in enc_file; this file should consist of a  sequence
   of lines of the form:

          pschar code

   where  pschar  is the PostScript name of the character, and code is its
   position in the encoding expressed as a decimal integer;  valid  values
   are  in  the range 0 to 255.  Lines starting with # and blank lines are
   ignored.  The code for each character  given  in  the  font  file  must
   correspond  to  the  code for the character in encoding file, or to the
   code in the default encoding for the font if the PostScript font is not
   to  be reencoded.  This code can be used with the \N escape sequence in
   troff to select the character, even if the character does  not  have  a
   groff  name.   Every  character  in  the  font  file  must exist in the
   PostScript font, and the widths given in the font file must  match  the
   widths  used  in  the  PostScript font.  grops assumes that a character
   with a groff name of space is blank (makes no marks on  the  page);  it
   can make use of such a character to generate more efficient and compact
   PostScript output.

   Note that grops is able to display all glyphs in a PostScript font, not
   only  256.   enc_file  (or  the  default  encoding  if no encoding file
   specified)  just  defines  the  order  of  glyphs  for  the  first  256
   characters;  all  other  glyphs  are  accessed with additional encoding
   vectors which grops produces on the fly.

   grops can automatically include the  downloadable  fonts  necessary  to
   print  the document.  Such fonts must be in PFA format.  Use pfbtops(1)
   to convert a Type 1 font in PFB format.  Any downloadable  fonts  which
   should,  when required, be included by grops must be listed in the file
   /usr/share/groff/1.22.3/font/devps/download;  this  should  consist  of
   lines of the form

          font filename

   where font is the PostScript name of the font, and filename is the name
   of the file containing the font; lines beginning with # and blank lines
   are  ignored;  fields  may  be separated by tabs or spaces; filename is
   searched for using the same mechanism  that  is  used  for  groff  font
   metric files.  The download file itself is also searched for using this
   mechanism; currently, only the first found file in  the  font  path  is
   used.

   If  the  file  containing  a  downloadable  font  or  imported document
   conforms to the Adobe  Document  Structuring  Conventions,  then  grops
   interprets  any  comments  in the files sufficiently to ensure that its
   own output is conforming.  It also supplies any needed  font  resources
   that  are  listed  in  the  download  file  as  well as any needed file
   resources.  It is also able to handle inter-resource dependencies.  For
   example, suppose that you have a downloadable font called Garamond, and
   also a downloadable  font  called  Garamond-Outline  which  depends  on
   Garamond  (typically  it  would  be  defined  to  copy  Garamond's font
   dictionary, and  change  the  PaintType),  then  it  is  necessary  for
   Garamond  to appear before Garamond-Outline in the PostScript document.
   grops handles this automatically provided that  the  downloadable  font
   file for Garamond-Outline indicates its dependence on Garamond by means
   of the Document Structuring Conventions, for example by beginning  with
   the following lines

          %!PS-Adobe-3.0 Resource-Font
          %%DocumentNeededResources: font Garamond
          %%EndComments
          %%IncludeResource: font Garamond

   In this case both Garamond and Garamond-Outline would need to be listed
   in the download file.  A downloadable font should not include  its  own
   name in a %%DocumentSuppliedResources comment.

   grops  does  not  interpret  %%DocumentFonts comments.  The %%Document
   NeededResources,    %%DocumentSuppliedResources,     %%IncludeResource,
   %%BeginResource,  and  %%EndResource  comments  (or  possibly  the  old
   %%DocumentNeededFonts, %%DocumentSuppliedFonts, %%IncludeFont, %%Begin
   Font, and %%EndFont comments) should be used.

   In the default setup there are styles called R, I, B, and BI mounted at
   font positions 1 to 4.  The fonts are grouped into families A,  BM,  C,
   H, HN, N, P, and T having members in each of these styles:

          AR     AvantGarde-Book
          AI     AvantGarde-BookOblique
          AB     AvantGarde-Demi
          ABI    AvantGarde-DemiOblique
          BMR    Bookman-Light
          BMI    Bookman-LightItalic
          BMB    Bookman-Demi
          BMBI   Bookman-DemiItalic
          CR     Courier
          CI     Courier-Oblique
          CB     Courier-Bold
          CBI    Courier-BoldOblique
          HR     Helvetica
          HI     Helvetica-Oblique
          HB     Helvetica-Bold
          HBI    Helvetica-BoldOblique
          HNR    Helvetica-Narrow
          HNI    Helvetica-Narrow-Oblique
          HNB    Helvetica-Narrow-Bold
          HNBI   Helvetica-Narrow-BoldOblique
          NR     NewCenturySchlbk-Roman
          NI     NewCenturySchlbk-Italic
          NB     NewCenturySchlbk-Bold
          NBI    NewCenturySchlbk-BoldItalic
          PR     Palatino-Roman
          PI     Palatino-Italic
          PB     Palatino-Bold
          PBI    Palatino-BoldItalic
          TR     Times-Roman
          TI     Times-Italic
          TB     Times-Bold
          TBI    Times-BoldItalic

   There is also the following font which is not a member of a family:

          ZCMI   ZapfChancery-MediumItalic

   There  are also some special fonts called S for the PS Symbol font, and
   SS, containing slanted lowercase Greek letters taken  from  PS  Symbol.
   Zapf   Dingbats   is  available  as  ZD,  and  a  reversed  version  of
   ZapfDingbats (with symbols  pointing  in  the  opposite  direction)  is
   available  as  ZDR; most characters in these fonts are unnamed and must
   be accessed using \N.

   The default color for \m and \M is black; for  colors  defined  in  the
   'rgb'   color   space   setrgbcolor  is  used,  for  'cmy'  and  'cmyk'
   setcmykcolor, and for 'gray' setgray.   Note  that  setcmykcolor  is  a
   PostScript LanguageLevel 2 command and thus not available on some older
   printers.

   grops understands various X  commands  produced  using  the  \X  escape
   sequence; grops only interprets commands that begin with a ps: tag.

   \X'ps: exec code'
          This  executes  the  arbitrary PostScript commands in code.  The
          PostScript currentpoint is set to the position of the \X command
          before  executing code.  The origin is at the top left corner of
          the  page,  and  y  coordinates  increase  down  the  page.    A
          procedure  u  is  defined  that  converts  groff  units  to  the
          coordinate system in effect (provided the  user  doesn't  change
          the scale).  For example,

                 .nr x 1i
                 \X'ps: exec \nx u 0 rlineto stroke'

          draws a horizontal line one inch long.  code may make changes to
          the graphics state, but any changes persist only to the  end  of
          the  page.  A dictionary containing the definitions specified by
          the def and mdef is on top of the  dictionary  stack.   If  your
          code  adds  definitions  to this dictionary, you should allocate
          space for them using  \X'ps mdef n'.   Any  definitions  persist
          only  until  the  end  of  the  page.   If you use the \Y escape
          sequence with an argument that names a macro,  code  can  extend
          over multiple lines.  For example,

                 .nr x 1i
                 .de y
                 ps: exec
                 \nx u 0 rlineto
                 stroke
                 ..
                 \Yy

          is  another  way  to draw a horizontal line one inch long.  Note
          the single backslash before 'nx' -- the  only  reason  to  use  a
          number  register  while  defining  the macro 'y' is to convert a
          user-specified dimension '1i' to internal groff units which  are
          in turn converted to PS units with the u procedure.

          grops  wraps  user-specified  PostScript code into a dictionary,
          nothing more.  In particular,  it  doesn't  start  and  end  the
          inserted code with save and restore, respectively.  This must be
          supplied by the user, if necessary.

   \X'ps: file name'
          This is the same as the exec command except that the  PostScript
          code is read from file name.

   \X'ps: def code'
          Place a PostScript definition contained in code in the prologue.
          There should be at most one definition  per  \X  command.   Long
          definitions  can be split over several \X commands; all the code
          arguments are simply joined together separated by newlines.  The
          definitions  are  placed  in a dictionary which is automatically
          pushed on the dictionary stack when an exec command is executed.
          If  you use the \Y escape sequence with an argument that names a
          macro, code can extend over multiple lines.

   \X'ps: mdef n code'
          Like def, except that code may  contain  up  to  n  definitions.
          grops  needs  to know how many definitions code contains so that
          it can create an appropriately sized  PostScript  dictionary  to
          contain them.

   \X'ps: import file llx lly urx ury width [ height ]'
          Import  a PostScript graphic from file.  The arguments llx, lly,
          urx, and ury give the bounding box of the graphic in the default
          PostScript  coordinate  system; they should all be integers; llx
          and lly are the x and y coordinates of the lower left corner  of
          the  graphic;  urx  and  ury  are the x and y coordinates of the
          upper right corner of the graphic; width and height are integers
          that  give  the  desired  width and height in groff units of the
          graphic.

          The graphic is scaled so that it has this width and  height  and
          translated  so  that  the  lower  left  corner of the graphic is
          located at the position associated  with  \X  command.   If  the
          height  argument  is omitted it is scaled uniformly in the x and
          y directions so that it has the specified width.

          Note that the contents of the \X command are not interpreted  by
          troff;  so  vertical  space for the graphic is not automatically
          added, and the width and height arguments  are  not  allowed  to
          have attached scaling indicators.

          If   the  PostScript  file  complies  with  the  Adobe  Document
          Structuring Conventions and contains  a  %%BoundingBox  comment,
          then the bounding box can be automatically extracted from within
          groff by using the psbb request.

          See groff_tmac(5) for a description of  the  PSPIC  macro  which
          provides  a  convenient  high-level  interface  for inclusion of
          PostScript graphics.

   \X'ps: invis'
   \X'ps: endinvis'
          No output is generated for text and drawing  commands  that  are
          bracketed  with  these \X commands.  These commands are intended
          for use  when  output  from  troff  is  previewed  before  being
          processed  with  grops;  if  the  previewer is unable to display
          certain characters or other constructs,  then  other  substitute
          characters   or   constructs  can  be  used  for  previewing  by
          bracketing them with these \X commands.

          For example, gxditview is not able  to  display  a  proper  \(em
          character because the standard X11 fonts do not provide it; this
          problem can be overcome by executing the following request

                 .char \(em \X'ps: invis'\
                 \Z'\v'-.25m'\h'.05m'\D'l .9m 0'\h'.05m''\
                 \X'ps: endinvis'\(em

          In this case, gxditview is unable to display the \(em  character
          and  draws the line, whereas grops prints the \(em character and
          ignores the line (this code is already in file Xps.tmac which is
          loaded  if  a  document  intended  for  grops  is previewed with
          gxditview).

   If a PostScript procedure BPhook has been defined via  a  'ps: def'  or
   'ps: mdef'  device  command,  it  is executed at the beginning of every
   page (before anything is drawn or written by groff).  For  example,  to
   underlay  the  page  contents  with the word 'DRAFT' in light gray, you
   might use

          .de XX
          ps: def
          /BPhook
          { gsave .9 setgray clippath pathbbox exch 2 copy
            .5 mul exch .5 mul translate atan rotate pop pop
            /NewCenturySchlbk-Roman findfont 200 scalefont setfont
            (DRAFT) dup stringwidth pop -.5 mul -70 moveto show
            grestore }
          def
          ..
          .devicem XX

   Or, to cause lines and polygons to be drawn with  square  linecaps  and
   mitered  linejoins instead of the round linecaps and linejoins normally
   used by grops, use

          .de XX
          ps: def
          /BPhook { 2 setlinecap 0 setlinejoin } def
          ..
          .devicem XX

   (square linecaps, as opposed to butt linecaps (0 setlinecap), give true
   corners in boxed tables even though the lines are drawn unconnected).

   Encapsulated PostScript
   grops  itself  doesn't emit bounding box information.  With the help of
   Ghostscript  the  following  simple  script,  groff2eps,  produces   an
   encapsulated PS file.

          #! /bin/sh
          groff -P-b16 $1 > $1.ps
          gs -dNOPAUSE -sDEVICE=bbox -- $1.ps 2> $1.bbox
          sed -e "/^%%Orientation/r $1.bbox" \
              -e "/^%!PS-Adobe-3.0/s/$/ EPSF-3.0/" $1.ps > $1.eps
          rm $1.ps $1.bbox

   Just say

          groff2eps foo

   to convert file foo to foo.eps.

   TrueType and other font formats
   TrueType  fonts  can  be  used with grops if converted first to Type 42
   format, a special PostScript  wrapper  equivalent  to  the  PFA  format
   mentioned  in  pfbtops(1).   There  are  several  different  methods to
   generate a type42 wrapper and  most  of  them  involve  the  use  of  a
   PostScript interpreter such as Ghostscript -- see gs(1).

   Yet,   the   easiest   method  involves  the  use  of  the  application
   ttftot42(1).  This program uses freetype(3) (version 1.3.1) to generate
   type42  font  wrappers and well-formed AFM files that can be fed to the
   afmtodit(1) script to create appropriate metric files.   The  resulting
   font  wrappers  should  be added to the download file.  ttftot42 source
   code  can  be  downloaded  from  ftp://www.giga.or.at/pub/nih/ttftot42/
   ftp://www.giga.or.at/pub/nih/ttftot42/.

   Another  solution  for  creating  type42  wrappers is to use FontForge,
   available from http://fontforge.sf.net http://fontforge.sf.net.  This
   font editor can convert most outline font formats.

FONT INSTALLATION

   This section gives a summary of the above explanations; it can serve as
   a step-by-step font installation guide for grops.

    *  Convert your font to something groff understands.  This is either a
       PostScript  Type 1 font in PFA format or a PostScript Type 42 font,
       together with an AFM file.

       The very first characters in a PFA file look like this:

              %!PS-AdobeFont-1.0:

       A PFB file has this also in the  first  line,  but  the  string  is
       preceded with some binary bytes.

       The very first characters in a Type 42 font file look like this:

              %!PS-TrueTypeFont

       This is a wrapper format for TrueType fonts.  Old PS printers might
       not support it (this is, they don't have a built-in  TrueType  font
       interpreter).

       If  your  font is in PFB format (such fonts normally have '.pfb' as
       the file extension), you might use groff's  pfbtops(1)  program  to
       convert  it to PFA.  For TrueType fonts, try ttftot42 or fontforge.
       For all other font formats use fontforge  which  can  convert  most
       outline font formats.

    *  Convert  the  AFM  file  to  a groff font description file with the
       afmtodit(1) program.  An example call is

              afmtodit Foo-Bar-Bold.afm textmap FBB

       which converts the metric file 'Foo-Bar-Bold.afm' to the groff font
       'FBB'.   If  you  have a font family which comes with normal, bold,
       italic, and bold italic faces, it is recommended to use the letters
       R, B, I, and BI, respectively, as postfixes in the groff font names
       to make groff's '.fam' request work.  An example is groff's  built-
       in  Times-Roman font: The font family name is T, and the groff font
       names are TR, TB, TI, and TBI.

    *  Install both the groff font description files and the  fonts  in  a
       'devps'  subdirectory  of the font path which groff finds.  See the
       ENVIRONMENT section in the troff(1) man page which lists the actual
       value  of the font path.  Note that groff doesn't use the AFM files
       (but it is a good idea to store them anyway).

    *  Register all fonts which must be downloaded to the printer  in  the
       'devps/download'  file.   Only the first occurrence of this file in
       the font path is read.  This means that you should copy the default
       'download'  file  to  the first directory in your font path and add
       your fonts there.  To continue the above example we assume that the
       PS font name for Foo-Bar-Bold.pfa is 'XY-Foo-Bar-Bold' (the PS font
       name is stored in the internalname field in the 'FBB'  file),  thus
       the following line should be added to 'download'.

              XY-Foo-Bar-Bold Foo-Bar-Bold.pfa

OLD FONTS

   groff  versions  1.19.2 and earlier contain a slightly different set of
   the 35 Adobe core fonts; the difference  is  mainly  the  lack  of  the
   'Euro'  glyph  and  a  reduced  set  of  kerning  pairs.  For backwards
   compatibility, these old fonts are installed also in the

          /usr/share/groff/1.22.3/oldfont/devps

   directory.

   To use them, make sure that grops finds the fonts  before  the  default
   system  fonts  (with the same names): Either add command line option -F
   to grops

          groff -Tps -P-F -P/usr/share/groff/1.22.3/oldfont ...

   or add the directory to groff's font path environment variable

          GROFF_FONT_PATH=/usr/share/groff/1.22.3/oldfont

ENVIRONMENT

   GROPS_PROLOGUE
          If this is set to foo, then grops uses the file foo (in the font
          path) instead of the default prologue file prologue.  The option
          -P overrides this environment variable.

   GROFF_FONT_PATH
          A list of  directories  in  which  to  search  for  the  devname
          directory  in  addition  to  the default ones.  See troff(1) and
          groff_font(5) for more details.

   SOURCE_DATE_EPOCH
          A timestamp (expressed as seconds since the Unix epoch)  to  use
          as the creation timestamp in place of the current time.

FILES

   /usr/share/groff/1.22.3/font/devps/DESC
          Device description file.

   /usr/share/groff/1.22.3/font/devps/F
          Font description file for font F.

   /usr/share/groff/1.22.3/font/devps/download
          List of downloadable fonts.

   /usr/share/groff/1.22.3/font/devps/text.enc
          Encoding used for text fonts.

   /usr/share/groff/1.22.3/tmac/ps.tmac
          Macros for use with grops; automatically loaded by troffrc

   /usr/share/groff/1.22.3/tmac/pspic.tmac
          Definition of PSPIC macro, automatically loaded by ps.tmac.

   /usr/share/groff/1.22.3/tmac/psold.tmac
          Macros  to  disable  use  of  characters  not  present  in older
          PostScript printers (e.g., 'eth' or 'thorn').

   /tmp/gropsXXXXXX
          Temporary file.  See groff(1) for details  on  the  location  of
          temporary files.

SEE ALSO

   afmtodit(1),     groff(1),    troff(1),    pfbtops(1),    groff_out(5),
   groff_font(5), groff_char(7), groff_tmac(5)

   PostScript  Language  Document  Structuring  Conventions  Specification
   http://partners.adobe.com/public/developer/en/ps/5001.DSC_Spec.pdf

COPYING

   Copyright  1989-2014 Free Software Foundation, Inc.

   Permission  is  granted  to make and distribute verbatim copies of this
   manual provided the copyright notice and  this  permission  notice  are
   preserved on all copies.

   Permission  is granted to copy and distribute modified versions of this
   manual under the conditions for verbatim  copying,  provided  that  the
   entire  resulting  derived  work  is  distributed  under the terms of a
   permission notice identical to this one.

   Permission is granted to  copy  and  distribute  translations  of  this
   manual  into  another language, under the above conditions for modified
   versions, except  that  this  permission  notice  may  be  included  in
   translations approved by the Free Software Foundation instead of in the
   original English.





Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.