groffer(1) — Linux manual page

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groffer(1)                 General Commands Manual                groffer(1)

Name         top

       groffer - display groff files and man pages on X and tty

Synopsis         top

       groffer [mode-option ...] [groff-option ...] [man-option ...] [X-
               option ...] [--] [filespec ...]

       groffer -h
       groffer --help

       groffer -v
       groffer --version

Description         top

       The groffer program is the easiest way to use groff(1).  It can
       display arbitrary documents written in the groff language, see
       groff(7), or other roff languages, see roff(7), that are compatible
       to the original troff language.  It finds and runs all necessary
       groff preprocessors, such as chem.

       The groffer program also includes many of the features for finding
       and displaying the Unix manual pages (man pages), such that it can be
       used as a replacement for a man(1) program.  Moreover, compressed
       files that can be handled by gzip(1) or bzip2(1) are decompressed on-

       The normal usage is quite simple by supplying a file name or name of
       a man page without further options.  But the option handling has many
       possibilities for creating special behaviors.  This can be done ei‐
       ther in configuration files, with the shell environment variable
       GROFFER_OPT, or on the command line.

       The output can be generated and viewed in several different ways
       available for groff.  This includes the X Window System-based groff
       program gxditview(1), each PostScript, PDF, or DVI display program, a
       web browser by generating HTML or XHTML in www mode, or several
       text modes in text terminals.

       Most of the options that must be named when running groff directly
       are determined automatically for groffer, due to the internal usage
       of the grog(1) program.  But all parts can also be controlled manual‐
       ly by arguments.

       Several file names can be specified on the command-line arguments.
       They are transformed into a single document in the normal way of

       Option handling is done in GNU style.  Options and file names can be
       mixed freely.  The option “--” closes the option handling, all fol‐
       lowing arguments are treated as file names.  Long options can be ab‐
       breviated in several ways.

Option Overview         top

       breaking options

               [-h | --help] [-v | --version]

       groffer mode options

               [--auto] [--default] [--default-modes mode1,mode2,...]
               [--dvi] [--groff] [--html] [--latin1] [--mode display_mode]
               [--pdf] [--pdf2] [--ps] [--source] [--text] [--to-stdout]
               [--tty] [--utf8] [--viewer prog] [--www] [--xhtml]
               [--x | --X]

       options related to groff

               [-T | --device device]
               [-Z | --intermediate-output | --ditroff]

              All further groff short options are accepted.

       options for man pages

               [--apropos] [--apropos-data] [--apropos-devel]
               [--apropos-progs] [--man] [--no-man] [--no-special]

       long options taken over from GNU man

               [--all] [--ascii] [--ditroff] [--extension suffix]
               [--locale language] [--local-file] [--location | --where]
               [--manpath dir1:dir2:...] [--no-location] [--pager program]
               [--sections sec1:sec2:...] [--systems sys1,sys2,...]
               [--troff-device device]

              Further long options of GNU man are accepted as well.

       options mapped to X Window System Toolkit Intrinsics options

               [--bd | --bordercolor pixels] [--bg | --background color]
               [--bw | --borderwidth pixels] [--display X-display]
               [--fg | --foreground color] [--fn | --ft | --font font_name]
               [--geometry size_pos] [--resolution value] [--rv]
               [--title string] [--xrm X-resource]

       options for development

               [--debug] [--debug-filenames] [--debug-grog] [--debug-keep]
               [--debug-params] [--debug-tmpdir] [--do-nothing]
               [--print text] [-V]

       filespec arguments

              The filespec parameters are all arguments that are neither an
              option nor an option argument.  They usually mean a file name
              or a man page searching scheme.

              In the following, the term section_extension is used.  It
              means a word that consists of a man section that is optionally
              followed by an extension.  The name of a man section is a sin‐
              gle character from [1–9on], the extension is some word.  The
              extension is mostly lacking.

              No filespec parameters means standard input.

              -         stands for standard input (can occur several times).

              filename  the path name of an existing file.

              section_extension name
                        search the man page name in the section with
                        optional extension section_extension.

              man:name  man page in the lowest man section that has name.

              name      if name is not an existing file search for the
                        man page name in the lowest man section.

Option Details         top

       The groffer program can usually be run with very few options.  But
       for special purposes, it supports many options.  These can be
       classified in 5 option classes.

       All short options of groffer are compatible with the short options of
       groff(1).  All long options of groffer are compatible with the long
       options of man(1).

       Arguments for long option names can be abbreviated in several ways.
       First, the argument is checked whether it can be prolonged as is.
       Furthermore, each minus sign - is considered as a starting point for
       a new abbreviation.  This leads to a set of multiple abbreviations
       for a single argument.  For example, --de-n-f can be used as an
       abbreviation for --debug-not-func, but --de-n works as well.  If the
       abbreviation of the argument leads to several resulting options an
       error is raised.

       These abbreviations are only allowed in the environment variable
       GROFFER_OPT, but not in the configuration files.  In configuration,
       all long options must be exact.

   groffer breaking options
       As soon as one of these options is found on the command line it is
       executed, printed to standard output, and the running groffer is
       terminated thereafter.  All other arguments are ignored.

       -h | --help
              Print help information with a short explanation of options to
              standard output.

       -v | --version
              Print version information to standard output.

   groffer mode options
       The display mode and the viewer programs are determined by these
       options.  If none of these mode and viewer options is specified
       groffer tries to find a suitable display mode automatically.  The
       default modes are mode pdf, mode ps, mode html, mode xhtml, mode x,
       and mode dvi in the X Window System with different viewers and mode
       tty with device utf8 under less on a terminal; other modes are tested
       if the programs for the main default mode do not exist.

       In the X Window System, many programs create their own window when
       called.  groffer can run these viewers as an independent program in
       the background.  As this does not work in text mode on a terminal
       (tty) there must be a way to know which viewers are X Window System-
       based graphical programs.  The groffer script has a small amount of
       information on some viewer names.  If a viewer argument of the
       command-line chooses an element that is recognized as an X Window
       System-based program in this list, it is treated as a viewer that can
       run in the background.  Unrecognized viewers are not run in the

       For each mode, you are free to choose whatever viewer you want.  That
       need not be some graphical viewer suitable for this mode.  There is a
       chance to view the output source; for example, the combination of the
       options --mode=ps and --viewer=less shows the content of the
       PostScript output, the source code, with the pager less.

       --auto Equivalent to --mode=auto.

              Reset all configuration from previously processed command-line
              options to the default values.  This is useful to wipe out all
              former options of the configuration, in GROFFER_OPT, and
              restart option processing using only the rest of the command

       --default-modes mode1,mode2,...
              Set the sequence of modes for auto mode to the comma separated
              list given in the argument.  See --mode for details on modes.
              Display in the default manner; actually, this means to try the
              modes x, ps, and tty in this sequence.

       --dvi  Equivalent to --mode=dvi.  Known DVI viewers for the X Window
              System include xdvi(1) and dvilx(1).

              Equivalent to --mode=groff.

       --html Equivalent to --mode=html.

       --mode value
              Set the display mode.  The following mode values are

              auto   Select the automatic determination of the display mode.
                     The sequence of modes that are tried can be set with
                     the --default-modes option.  Useful for restoring the
                     default mode when a different mode was specified

              dvi    Display formatted input in a DVI viewer program.  By
                     default, the formatted input is displayed with the
                     xdvi(1) program.

              groff  After the file determination, switch groffer to process
                     the input like groff(1) would do.  This disables the
                     groffer viewing features.

              html   Translate the input into HTML format and display the
                     result in a web browser program.  By default, the
                     existence of a sequence of standard web browsers is
                     tested, starting with konqueror(1) and mozilla(1).  The
                     text HTML viewer is lynx(1).  By default, the existence
                     of a sequence of standard web browsers is tested,
                     starting with konqueror(1) and mozilla(1).  The text
                     HTML viewer is lynx(1).

              pdf    Transform roff input files into a PDF file by using the
                     groff(1) device -Tpdf.  This is the default PDF
                     generator.  The generated PDF file is displayed with
                     suitable viewer programs, such as okular(1).

              pdf2   This is the traditional pdf mode.  Sometimes this mode
                     produces more correct output than the default PDF mode.
                     By default, the input is formatted by groff using the
                     PostScript device, then it is transformed into the PDF
                     file format using gs(1), or ps2pdf(1).  If that's not
                     possible, the PostScript mode (ps) is used instead.
                     Finally it is displayed using different viewer

              ps     Display formatted input in a PostScript viewer program.
                     By default, the formatted input is displayed in one of
                     many viewer programs.

              text   Format in a groff text mode and write the result to
                     standard output without a pager or viewer program.  The
                     text device, latin1 by default, can be chosen with
                     option -T.

              tty    Format in a groff text mode and write the result to
                     standard output using a text pager program, even when
                     in the X Window System.

              www    Equivalent to --mode=html.

              x      Display the formatted input in a native roff viewer.
                     By default, the formatted input is displayed with the
                     gxditview(1) program being distributed together with
                     groff.  But the legacy X Window System application
                     xditview(1) can also be chosen with the option
                     --viewer.  The default resolution is 75dpi, but 100dpi
                     are also possible.  The default groff device for the
                     resolution of 75dpi is X75-12, for 100dpi it is X100.
                     The corresponding groff intermediate output for the
                     actual device is generated and the result is displayed.
                     For a resolution of 100dpi, the default width of the
                     geometry of the display program is chosen to 850dpi.

              X      Equivalent to --mode=x.

              xhtml  Translate the input into XHTML format, which is an XML
                     version of HTML.  Then display the result in a web
                     browser program, mostly the known HTML viewers.

              The following modes do not use the groffer viewing features.
              They are only interesting for advanced applications.

              groff  Generate device output with plain groff without using
                     the special viewing features of groffer.  If no device
                     was specified by option -T the groff default ps is

              source Output the roff source code of the input files without
                     further processing.

       --pdf  Equivalent to --mode=pdf.
       --pdf2 Equivalent to --mode=pdf2.

       --ps   Equivalent to --mode=ps.  Common PostScript viewers include
              okular(1), evince(1), gv(1), ghostview(1), and gs(1), In each
              case, arguments can be provided additionally.

              Equivalent to --mode=source.

       --text Equivalent to --mode=text.

              The file for the chosen mode is generated and its content is
              printed to standard output.  It will not be displayed in
              graphical mode.

       --tty  Equivalent to --mode=tty.  The standard pager is less(1).
              This option is equivalent to man option --pager=prog.  The
              option argument can be a file name or a program to be searched
              in $PATH; arguments can be provided additionally.

       --viewer prog
              Choose a viewer program for actual device or mode.  This can
              be a file name or a program to be searched in $PATH; arguments
              can be provided additionally.

       --www  Equivalent to --mode=html.

       --X | --x
              Equivalent to --mode=x.  Suitable viewer programs are
              gxditview(1) which is the default and xditview(1).

       --     Signals the end of option processing; all remaining arguments
              are interpreted as filespec parameters.

       Besides these, groffer accepts all short options that are valid for
       the groff(1) program.  All non-groffer options are sent unmodified
       via grog to groff.  So postprocessors, macro packages, compatibility
       with classical troff, and much more can be manually specified.

   Options related to groff
       All short options of groffer are compatible with the short options of
       groff(1).  The following of groff options have either an additional
       special meaning within groffer or make sense for normal usage.

       Because of the special outputting behavior of the groff option -Z
       groffer was designed to be switched into groff mode; the groffer
       viewing features are disabled there.  The other groff options do not
       switch the mode, but allow to customize the formatting process.

       --a    This generates an ASCII approximation of output in the
              text modes.  That could be important when the text pager has
              problems with control sequences in tty mode.

       --m file
              Add file as a groff macro file.  This is useful in case it
              cannot be recognized automatically.

       --P opt_or_arg
              Send the argument opt_or_arg as an option or option argument
              to the actual groff postprocessor.

       --T devname | --device devname
              This option determines groff's output device.  The most
              important devices are the text output devices for referring to
              the different character sets, such as ascii, utf8, latin1,
              utf8, and others.  Each of these arguments switches groffer
              into a text mode using this device, to mode tty if the actual
              mode is not a text mode.  The following devname arguments are
              mapped to the corresponding groffer --mode=devname option:
              dvi, html, xhtml, and ps.  All X* arguments are mapped to
              mode x.  Each other devname argument switches to mode groff
              using this device.

       --X    is equivalent to groff -X.  It displays the groff intermediate
              output with gxditview.  As the quality is relatively bad this
              option is deprecated; use --X instead because the x mode uses
              an X* device for a better display.

       -Z | --intermediate-output | --ditroff
              Switch into groff mode and format the input with the groff
              intermediate output without postprocessing; see groff_out(5).
              This is equivalent to option --ditroff of man, which can be
              used as well.

       All other groff options are supported by groffer, but they are just
       transparently transferred to groff without any intervention.  The
       options that are not explicitly handled by groffer are transparently
       passed to groff.  Therefore these transparent options are not
       documented here, but in groff(1).  Due to the automatism in groffer,
       none of these groff options should be needed, except for advanced

   Options for man pages
              Start the apropos(1) command or facility of man(1) for
              searching the filespec arguments within all man page
              descriptions.  Each filespec argument is taken for search as
              it is; section specific parts are not handled, such that 7
              groff searches for the two arguments 7 and groff, with a large
              result; for the filespec groff.7 nothing will be found.  The
              language locale is handled only when the called programs do
              support this; the GNU apropos and man -k do not.  The display
              differs from the apropos program by the following concepts:

              * Construct a groff frame similar to a man page to the output
                of apropos,

              * each filespec argument is searched on its own.

              * The restriction by --sections is handled as well,

              * wildcard characters are allowed and handled without a
                further option.

              Show only the apropos descriptions for data documents, these
              are the man(7) sections 4, 5, and 7.  Direct section
              declarations are ignored, wildcards are accepted.

              Show only the apropos descriptions for development documents,
              these are the man(7) sections 2, 3, and 9.  Direct section
              declarations are ignored, wildcards are accepted.

              Show only the apropos descriptions for documents on programs,
              these are the man(7) sections 1, 6, and 8.  Direct section
              declarations are ignored, wildcards are accepted.

              For each filespec argument search all man pages and display
              their description — or say that it is not a man page.  This is
              written from anew, so it differs from man's whatis output by
              the following concepts

              * each retrieved file name is added,

              * local files are handled as well,

              * the language and system locale is supported,

              * the display is framed by a groff output format similar to a
                man page,

              * wildcard characters are allowed without a further option.

       The following options were added to groffer for choosing whether the
       file name arguments are interpreted as names for local files or as a
       search pattern for man pages.  The default is looking up for local

       --man  Check the non-option command-line arguments (filespecs) first
              on being man pages, then whether they represent an existing
              file.  By default, a filespec is first tested whether it is an
              existing file.

       --no-man | --local-file
              Do not check for man pages.  --local-file is the corresponding
              man option.

              Disable former calls of --all, --apropos*, and --whatis.

   Long options taken over from GNU man
       The long options of groffer were synchronized with the long options
       of GNU man.  All long options of GNU man are recognized, but not all
       of these options are important to groffer, so most of them are just
       ignored.  These ignored man options are --catman, --troff, and --up‐

       In the following, the man options that have a special meaning for
       groffer are documented.

       If your system has GNU man installed the full set of long and short
       options of the GNU man program can be passed via the environment
       variable MANOPT; see man(1).

       --all  In searching man pages, retrieve all suitable documents in‐
              stead of only one.

       -7 | --ascii
              In text modes, display ASCII translation of special characters
              for critical environment.  This is equivalent to groff
              -mtty_char; see groff_tmac(5).

              Produce groff intermediate output.  This is equivalent to
              groffer -Z.

       --extension suffix
              Restrict man page search to file names that have suffix ap‐
              pended to their section element.  For example, in the file
              name /usr/share/man/man3/terminfo.3ncurses.gz the man page ex‐
              tension is ncurses.

       --locale language
              Set the language for man pages.  This has the same effect, but
              overwrites $LANG.

              Print the location of the retrieved files to standard error.

              Do not display the location of retrieved files; this resets a
              former call to --location.  This was added by groffer.

       --manpath 'dir1:dir2:...'
              Use the specified search path for retrieving man pages instead
              of the program defaults.  If the argument is set to the empty
              string "" the search for man page is disabled.

              Set the pager program in tty mode; default is less.  This can
              be set with --viewer.

       --sections sec1:sec2:...
              Restrict searching for man pages to the given sections, a
              colon-separated list.

       --systems sys1,sys2,...
              Search for man pages for the given operating systems; the ar‐
              gument systems is a comma-separated list.

              Equivalent to --location.

   X Window System Toolkit Intrinsics options
       The following long options were adapted from the corresponding X Win‐
       dow System Toolkit Intrinsics options.  groffer will pass them to the
       actual viewer program if it is an X Window System program.  Otherwise
       these options are ignored.

       Unfortunately these options use the old style of a single minus for
       long options.  For groffer that was changed to the standard with us‐
       ing a double minus for long options, for example, groffer uses the
       option --font for the X Window System Toolkit Intrinsics option

       See X(7) and the manual X Toolkit Intrinsics – C Language Interface
       for more details on these options and their arguments.

       --background color
              Set the background color of the viewer window.

       --bd pixels
              This is equivalent to --bordercolor.

       --bg color
              This is equivalent to --background.

       --bw pixels
              This is equivalent to --borderwidth.

       --bordercolor pixels
              Specifies the color of the border surrounding the viewer win‐

       --borderwidth pixels
              Specifies the width in pixels of the border surrounding the
              viewer window.

       --display X-display
              Set the X Window System display on which the viewer program
              shall be started.  See section “Display Names” in X(7) for the
              syntax of the argument.

       --foreground color
              Set the foreground color of the viewer window.

       --fg color
              This is equivalent to --foreground.

       --fn font_name
              This is equivalent to --font.

       --font font_name
              Set the font used by the viewer window.  The argument is an X
              Window System font name.

       --ft font_name
              This is equivalent to --font.

       --geometry size_pos
              Set the geometry of the display window, that means its size
              and its starting position.  See section “Geometry Specifica‐
              tions” in X(7) for the syntax of the argument.

       --resolution value
              Set X Window System resolution in dpi (dots per inch) in some
              viewer programs.  The only supported dpi values are 75 and
              100.  Actually, the default resolution for groffer is set to
              75dpi.  The resolution also sets the default device in mode x.

       --rv   Reverse foreground and background color of the viewer window.

       --title 'some text'
              Set the title for the viewer window.

       --xrm 'resource'
              Set the X Window System server resource to the given value.

   Options for development
              Enable all debugging options --debug-type.  The temporary
              files are kept and not deleted, the grog output is printed,
              the name of the temporary directory is printed, the displayed
              file names are printed, and the parameters are printed.

              Print the names of the files and man pages that are displayed
              by groffer.

              Print the output of all grog commands.

              Enable two debugging informations.  Print the name of the tem‐
              porary directory and keep the temporary files, do not delete
              them during the run of groffer.

              Print the parameters, as obtained from the configuration
              files, from GROFFER_OPT, and the command-line arguments.

              Print the name of the temporary directory.

              This is like --version, but without the output; no viewer is
              started.  This makes only sense in development.

              Just print the argument to standard error.  This is good for
              parameter check.

       -V     This is an advanced option for debugging only.  Instead of
              displaying the formatted input, a lot of groffer specific in‐
              formation is printed to standard output:

              * the output file name in the temporary directory,

              * the display mode of the actual groffer run,

              * the display program for viewing the output with its argu‐

              * the active parameters from the config files, the arguments
                in GROFFER_OPT, and the arguments of the command line,

              * the pipeline that would be run by the groff program, but
                without executing it.

       Other useful debugging options are the groff option -Z and

   Filespec arguments
       A filespec parameter is an argument that is not an option or option
       argument.  In groffer, filespec parameters are a file name or a tem‐
       plate for searching man pages.  These input sources are collected and
       composed into a single output file such as groff does.

       The strange POSIX behavior to regard all arguments behind the first
       non-option argument as filespec arguments is ignored.  The GNU behav‐
       ior to recognize options even when mixed with filespec arguments is
       used throughout.  But, as usual, the double minus argument -- ends
       the option handling and interprets all following arguments as
       filespec arguments; so the POSIX behavior can be easily adopted.

       The options --apropos* have a special handling of filespec arguments.
       Each argument is taken as a search scheme of its own.  Also a regexp
       (regular expression) can be used in the filespec.  For example, grof‐
       fer --apropos '^gro.f$' searches groff in the man page name, while
       groffer --apropos groff searches groff somewhere in the name or de‐
       scription of the man pages.

       All other parts of groffer, such as the normal display or the output
       with --whatis have a different scheme for filespecs.  No regular ex‐
       pressions are used for the arguments.  The filespec arguments are
       handled by the following scheme.

       It is necessary to know that on each system the man pages are sorted
       according to their content into several sections.  The classical man
       sections have a single-character name, either a digit from 1 to 9 or
       one of the characters n or o.

       This can optionally be followed by a string, the so-called extension.
       The extension allows the storage of several man pages with the same
       name in the same section.  But the extension is only rarely used;
       usually it is omitted.  Then the extensions are searched automatical‐
       ly by alphabet.

       In the following, we use the name section_extension for a word that
       consists of a single character section name or a section character
       that is followed by an extension.  Each filespec parameter can have
       one of the following forms in decreasing sequence.

       * No filespec parameters means that groffer waits for standard input.
         The minus option - always stands for standard input; it can occur
         several times.  If you want to look up a man page called - use the
         argument man:-.

       * Next a filespec is tested whether it is the path name of an exist‐
         ing file.  Otherwise it is assumed to be a searching pattern for a
         man page.

       * man:name(section_extension), man:name.section_extension,
         name(section_extension), or name.section_extension search the
         man page name in man section and possibly extension of

       * Now man:name searches for a man page in the lowest man section that
         has a document called name.

       * section_extension name is a pattern of 2 arguments that originates
         from a strange argument parsing of the man program.  Again, this
         searches the man page name with section_extension, a combination of
         a section character optionally followed by an extension.

       * We are left with the argument name which is not an existing file.
         So this searches for the man page called name in the lowest
         man section that has a document for this name.

       Several file name arguments can be supplied.  They are mixed by groff
       into a single document.  Note that the set of option arguments must
       fit to all of these file arguments.  So they should have at least the
       same style of the groff language.

Output Modes         top

       By default, the groffer program collects all input into a single
       file, formats it with the groff program for a certain device, and
       then chooses a suitable viewer program.  The device and viewer
       process in groffer is called a mode.  The mode and viewer of a
       running groffer program is selected automatically, but the user can
       also choose it with options.  The modes are selected by option the
       arguments of --mode=anymode.  Additionally, each of this argument can
       be specified as an option of its own, such as anymode.  Most of these
       modes have a viewer program, which can be chosen by the option

       Several different modes are offered: graphical modes for the X Window
       System, text modes, and some direct groff modes for debugging and

       By default, groffer first tries whether x mode is possible, then
       ps mode, and finally tty mode.  This mode testing sequence for
       auto mode can be changed by specifying a comma separated list of
       modes with the option --default-modes.

       The searching for man pages and the decompression of the input are
       active in every mode.

   Graphical display modes
       The graphical display modes work mostly in the X Window System
       environment (or similar implementations within other windowing
       environments).  The environment variable DISPLAY and the option
       --display are used for specifying the X Window System display to be
       used.  If this environment variable is empty, groffer assumes that
       the X Window System is not running and changes to a text mode.  You
       can change this automatic behavior by the option --default-modes.

       Known viewers for the graphical display modes and their standard X
       Window System viewer programs are

       * in a PDF viewer (pdf mode)

       * in a web browser (html, xhtml, or www mode)

       * in a PostScript viewer (ps mode)

       * X Window System roff viewers such as gxditview(1) or xditview(1)
         (in x mode)

       * in a DVI viewer program (dvi mode)

       The pdf mode has a major advantage — it is the only graphical display
       mode that allows searching for text within the viewer; this can be a
       really important feature.  Unfortunately, it takes some time to
       transform the input into the PDF format, so it was not chosen as the
       major mode.

       These graphical viewers can be customized by options of the X Window
       System Toolkit Intrinsics.  But the groffer options use a leading
       double minus instead of the single minus used by the X Window System
       Toolkit Intrinsics.

   Text modes
       There are two modes for text output, mode text for plain output with‐
       out a pager and mode tty for a text output on a text terminal using
       some pager program.

       If the variable DISPLAY is not set or empty, groffer assumes that it
       should use tty mode.

       In the actual implementation, the groff output device latin1 is cho‐
       sen for text modes.  This can be changed by specifying option -T or

       The pager to be used can be specified by one of the options --pager
       and --viewer, or by the environment variable PAGER.  If all of this
       is not used the less(1) program with the option -r for correctly dis‐
       playing control sequences is used as the default pager.

   Special modes for debugging and development
       These modes use the groffer file determination and decompression.
       This is combined into a single input file that is fed directly into
       groff with different strategy without the groffer viewing facilities.
       These modes are regarded as advanced, they are useful for debugging
       and development purposes.

       The source mode with option --source just displays the decompressed

       Option --to-stdout does not display in a graphical mode.  It just
       generates the file for the chosen mode and then prints its content to
       standard output.

       The groff mode passes the input to groff using only some suitable op‐
       tions provided to groffer.  This enables the user to save the gener‐
       ated output into a file or pipe it into another program.

       In groff mode, the option -Z disables post-processing, thus producing
       the groff intermediate output.  In this mode, the input is formatted,
       but not postprocessed; see groff_out(5) for details.

       All groff short options are supported by groffer.

Man Page Searching         top

       The default behavior of groffer is to first test whether a file
       parameter represents a local file; if it is not an existing file
       name, it is assumed to represent the name of a man page.  The
       following options can be used to determine whether the arguments
       should be handled as file name or man page arguments.

       --man  forces to interpret all file parameters as filespecs for
              searching man pages.

              disable the man searching; so only local files are displayed.

       If neither a local file nor a man page was retrieved for some file
       parameter a warning is issued on standard error, but processing is

   Search algorithm
       Let us now assume that a man page should be searched.  The groffer
       program provides a search facility for man pages.  All long options,
       all environment variables, and most of the functionality of the GNU
       man(1) program were implemented.  The search algorithm shall
       determine which file is displayed for a given man page.  The process
       can be modified by options and environment variables.

       The only man action that is omitted in groffer are the preformatted
       man pages, also called cat pages.  With the excellent performance of
       the actual computers, the preformatted man pages aren't necessary any
       longer.  Additionally, groffer is a roff program; it wants to read
       roff source files and format them itself.

       The algorithm for retrieving the file for a man page needs first a
       set of directories.  This set starts with the so-called man path that
       is modified later on by adding names of operating system and
       language.  This arising set is used for adding the section
       directories which contain the man page files.

       The man path is a list of directories that are separated by colon.
       It is generated by the following methods.

       * The environment variable MANPATH can be set.

       * It can be read from the arguments of the environment variable

       * The man path can be manually specified by using the option
         --manpath.  An empty argument disables the man page searching.

       * When no man path was set the manpath(1) program is tried to
         determine one.

       * If this does not work a reasonable default path from $PATH is

       We now have a starting set of directories.  The first way to change
       this set is by adding names of operating systems.  This assumes that
       man pages for several operating systems are installed.  This is not
       always true.  The names of such operating systems can be provided by
       3 methods.

       * The environment variable SYSTEM has the lowest precedence.

       * This can be overridden by an option in MANOPT.

       * This again is overridden by the command-line option --systems.

       Several names of operating systems can be given by appending their
       names, separated by a comma.

       The man path is changed by appending each system name as subdirectory
       at the end of each directory of the set.  No directory of the
       man path set is kept.  But if no system name is specified the
       man path is left unchanged.

       After this, the actual set of directories can be changed by language
       information.  This assumes that there exist man pages in different
       languages.  The wanted language can be chosen by several methods.

       * Environment variable LANG.

       * This is overridden by LC_MESSAGES.

       * This is overridden by LC_ALL.

       * This can be overridden by providing an option in MANOPT.

       * All these environment variables are overridden by the command-line
         option --locale.

       The default language can be specified by specifying one of the
       pseudo-language parameters C or POSIX.  This is like deleting a
       formerly given language information.  The man pages in the default
       language are usually in English.

       Of course, the language name is determined by man.  In GNU man, it is
       specified in the POSIX 1003.1 based format:


       but the two-letter code in <language> is sufficient for most purpos‐
       es.  If for a complicated language formulation no man pages are found
       groffer searches the country part consisting of these first two char‐
       acters as well.

       The actual directory set is copied thrice.  The language name is ap‐
       pended as subdirectory to each directory in the first copy of the ac‐
       tual directory set (this is only done when a language information is
       given).  Then the 2-letter abbreviation of the language name is ap‐
       pended as subdirectories to the second copy of the directory set
       (this is only done when the given language name has more than 2 let‐
       ters).  The third copy of the directory set is kept unchanged (if no
       language information is given this is the kept directory set).  These
       maximally 3 copies are appended to get the new directory set.

       We now have a complete set of directories to work with.  In each of
       these directories, the man files are separated in sections.  The name
       of a section is represented by a single character, a digit between 1
       and 9, or the character o or n, in this order.

       For each available section, a subdirectory man<section> exists con‐
       taining all man files for this section, where <section> is a single
       character as described before.  Each man file in a section directory
       has the form
       man<section>/<name>.<section>[<extension>][.<compression>], where
       <extension> and <compression> are optional.  <name> is the name of
       the man page that is also specified as filespec argument on the com‐
       mand line.

       The extension is an addition to the section.  This postfix acts like
       a subsection.  An extension occurs only in the file name, not in name
       of the section subdirectory.  It can be specified on the command

       On the other hand, the compression is just an information on how the
       file is compressed.  This is not important for the user, such that it
       cannot be specified on the command line.

       There are 4 methods to specify a section on the command line:

       * Environment variable MANSECT

       * Command-line option --sections

       * Appendix to the name argument in the form <name>.<section>

       * Preargument before the name argument in the form <section> <name>

       It is also possible to specify several sections by appending the sin‐
       gle characters separated by colons.  One can imagine that this means
       to restrict the man page search to only some sections.  The multiple
       sections are only possible for MANSECT and --sections.

       If no section is specified all sections are searched one after the
       other in the given order, starting with section 1, until a suitable
       file is found.

       There are 4 methods to specify an extension on the command line.  But
       it is not necessary to provide the whole extension name, some abbre‐
       viation is good enough in most cases.

       * Environment variable EXTENSION

       * Command-line option --extension

       * Appendix to the <name>.<section> argument in the form <name>.<sec‐

       * Preargument before the name argument in the form <section><exten‐
         sion> <name>

       For further details on man page searching, see man(1).

   Examples of man files
              This is an uncompressed file for the man page groff in sec‐
              tion 1.  It can be called by
              sh# groffer groff
              No section is specified here, so all sections should be
              searched, but as section 1 is searched first this file will be
              found first.  The file name is composed of the following com‐
              ponents.  /usr/share/man/ must be part of the man path; the
              subdirectory man1/ and the part .1 stand for the section;
              groff is the name of the man page.

              The file name is composed of the following components.
              /usr/local/share/man must be part of the man path; the subdi‐
              rectory man7/ and the part .7 stand for the section; groff is
              the name of the man page; the final part .gz stands for a com‐
              pression with gzip(1).  As the section is not the first one it
              must be specified as well.  This can be done by one of the
              following commands.
              sh# groffer groff.7
              sh# groffer 7 groff
              sh# groffer --sections=7 groff

              Here /usr/local/man must be in man path; the subdirectory
              man1/ and the file name part .1 stand for section 1; the name
              of the man page is ctags; the section has an extension
              emacs21; and the file is compressed as .bz2 with bzip2(1).
              The file can be viewed with one of the following commands
              sh# groffer ctags.1e
              sh# groffer 1e ctags
              sh# groffer --extension=e --sections=1 ctags
              where e works as an abbreviation for the extension emacs21.

              The directory /usr/man is now part of the man path; then there
              is a subdirectory for an operating system name linux/; next
              comes a subdirectory de/ for the German language; the section
              names man7 and .7 are known so far; man is the name of the
              man page; and .Z signifies the compression that can be handled
              by gzip(1).  We want now show how to provide several values
              for some options.  That is possible for sections and operating
              system names.  So we use as sections 5 and 7 and as system
              names linux and aix.  The command is then

              sh# groffer --locale=de --sections=5:7 --systems=linux,aix man
              sh# LANG=de MANSECT=5:7 SYSTEM=linux,aix groffer man

Decompression         top

       The program has a decompression facility.  If standard input or a
       file that was retrieved from the command line parameters is
       compressed with a format that is supported by either gzip(1) or
       bzip2(1) it is decompressed on-the-fly.  This includes the GNU .gz,
       .bz2, and the traditional .Z compression.  The program displays the
       concatenation of all decompressed input in the sequence that was
       specified on the command line.

Environment         top

       The groffer program supports many system variables, most of them by
       courtesy of other programs.  All environment variables of groff(1)
       and GNU man(1) and some standard system variables are honored.

   Native groffer variables
              Store options for a run of groffer.  The options specified in
              this variable are overridden by the options given on the
              command line.  The content of this variable is run through the
              shell builtin “eval”, so arguments containing whitespace or
              special shell characters should be quoted.  Do not forget to
              export this variable, otherwise it does not exist during the
              run of groffer.

   System variables
       The following variables have a special meaning for groffer.

              If set, this variable indicates that the X Window System is
              running.  Testing this variable decides on whether graphical
              or text output is generated.  This variable should not be
              changed by the user carelessly, but it can be used to start
              the graphical groffer on a remote X Window System terminal.
              For example, depending on your system, groffer can be started
              on the second monitor by the command

              sh# DISPLAY=:0.1 groffer what.ever &

       LANG   If one of these variables is set (in the above sequence), its
              content is interpreted as the locale, the language to be used,
              especially when retrieving man pages.  A locale name is typi‐
              cally of the form language[_territory[.codeset[@modifier]]],
              where language is an ISO 639 language code, territory is an
              ISO 3166 country code, and codeset is a character set or en‐
              coding identifier like ISO-8859-1 or UTF-8; see setlocale(3).
              The locale values C and POSIX stand for the default, i.e. the
              man page directories without a language prefix.  This is the
              same behavior as when all 3 variables are unset.

       PAGER  This variable can be used to set the pager for the tty output.
              For example, to disable the use of a pager completely set this
              variable to the cat(1) program

              sh# PAGER=cat groffer anything

       PATH   All programs within the groffer script are called without a
              fixed path.  Thus this environment variable determines the set
              of programs used within the run of groffer.

   groff variables
       The groffer program internally calls groff, so all environment vari‐
       ables documented in groff(1) are internally used within groffer as
       well.  The following variable has a direct meaning for the groffer

              If the value of this variable is an existing, writable direc‐
              tory, groffer uses it for storing its temporary files, just as
              groff does.  See the groff(1) man page for more details on the
              location of temporary files.

   man variables
       Parts of the functionality of the man program were implemented in
       groffer; support for all environment variables documented in man(1)
       was added to groffer, but the meaning was slightly modified due to
       the different approach in groffer; but the user interface is the
       same.  The man environment variables can be overwritten by options
       provided with MANOPT, which in turn is overwritten by the command

              Restrict the search for man pages to files having this exten‐
              sion.  This is overridden by option --extension; see there for

       MANOPT This variable contains options as a preset for man(1).  As not
              all of these are relevant for groffer only the essential parts
              of its value are extracted.  The options specified in this
              variable overwrite the values of the other environment vari‐
              ables that are specific to man.  All options specified in this
              variable are overridden by the options given on the command

              If set, this variable contains the directories in which the
              man page trees are stored.  This is overridden by option

              If this is a colon separated list of section names, the search
              for man pages is restricted to those manual sections in that
              order.  This is overridden by option --sections.

       SYSTEM If this is set to a comma separated list of names these are
              interpreted as man page trees for different operating systems.
              This variable can be overwritten by option --systems; see
              there for details.

       The environment variable MANROFFSEQ is ignored by groffer because the
       necessary preprocessors are determined automatically.

Configuration Files         top

       The groffer program can be preconfigured by two configuration files.

              System-wide configuration file for groffer.

              User-specific configuration file for groffer, where $HOME
              denotes the user's home directory.  This file is called after
              the system-wide configuration file to enable overriding by the

       Both files are handled for the configuration, but the configuration
       file in /etc comes first; it is overwritten by the configuration file
       in the home directory; both configuration files are overwritten by
       the environment variable GROFFER_OPT; everything is overwritten by
       the command-line arguments.

       The configuration files contain options that should be called as
       default for every groffer run.  These options are written in lines
       such that each contains either a long option, a short option, or a
       short option cluster; each with or without an argument.  So each line
       with configuration information starts with a minus character “-”; a
       line with a long option starts with two minus characters “--”, a line
       with a short option or short option cluster starts with a single
       minus “-”.

       The option names in the configuration files may not be abbreviated,
       they must be exact.

       The argument for a long option can be separated from the option name
       either by an equal sign “=” or by whitespace, i.e. one or several
       space or tab characters.  An argument for a short option or short
       option cluster can be directly appended to the option name or
       separated by whitespace.  The end of an argument is the end of the
       line.  It is not allowed to use a shell environment variable in an
       option name or argument.

       It is not necessary to use quotes in an option or argument, except
       for empty arguments.  An empty argument can be provided by appending
       a pair of quotes to the separating equal sign or whitespace; with a
       short option, the separator can be omitted as well.  For a long
       option with a separating equal sign “=”, the pair of quotes can be
       omitted, thus ending the line with the separating equal sign.  All
       other quote characters are cancelled internally.

       In the configuration files, arbitrary whitespace is allowed at the
       beginning of each line, it is just ignored.  Each whitespace within a
       line is replaced by a single space character “ ” internally.

       All lines of the configuration lines that do not start with a minus
       character are ignored, such that comments starting with “#” are
       possible.  So there are no shell commands in the configuration files.

       As an example, consider the following configuration file that can be
       used either in /etc/groff/groffer.conf or ~/.groff/groffer.conf .

       # groffer configuration file
       # groffer options that are used in each call of groffer
       --viewer=gxditview -geometry 900x1200

       The lines starting with # are just ignored, so they act as command
       lines.  This configuration sets four groffer options (the lines
       starting with “-”).  This has the following effects:

       * Use a text color of DarkBlue in all viewers that support this, such
         as gxditview.

       * Use a resolution of 100dpi in all viewers that support this, such
         as gxditview.  By this, the default device in x mode is set to

       * Force gxditview(1) as the x-mode viewer using the geometry option
         for setting the width to 900px and the height to 1200px.  This ge‐
         ometry is suitable for a resolution of 100dpi.

       * Use xpdf(1) as the pdf-mode viewer with the argument -Z 150.

Example         top

       The usage of groffer is very easy.  Usually, it is just called with a
       file name or man page.  The following examples, however, show that
       groffer has much more fancy capabilities.

       sh# groffer /usr/local/share/doc/groff/

       Decompress, format and display the compressed file in
       the directory /usr/local/share/doc/groff, using the standard viewer
       gxditview as graphical viewer when in the X Window System, or the
       less(1) pager program otherwise.

       sh# groffer groff

       If the file ./groff exists use it as input.  Otherwise interpret the
       argument as a search for the man page named groff in the smallest
       possible man section, being section 1 in this case.

       sh# groffer man:groff

       search for the man page of groff even when the file ./groff exists.

       sh# groffer groff.7
       sh# groffer 7 groff

       search the man page of groff in man section 7.  This section search
       works only for a digit or a single character from a small set.

       sh# groffer fb.modes

       If the file ./fb.modes does not exist interpret this as a search for
       the man page of fb.modes.  As the extension modes is not a single
       character in classical section style the argument is not split to a
       search for fb.

       sh# groffer groff ’troff(1)’ man:roff

       The arguments that are not existing files are looked-up as the fol‐
       lowing man pages: groff (automatic search, should be found in
       man section 1), troff (in section 1), and roff (in the section with
       the lowest number, being 7 in this case).  The quotes around
       ’troff(1)’ are necessary because the parentheses are special shell
       characters; escaping them with a backslash character \( and \) would
       be possible, too.  The formatted files are concatenated and displayed
       in one piece.

       sh# LANG=de groffer --man --viewer=galeon ls

       Retrieve the German man page (language de) for the ls program, decom‐
       press it, format it to html or xhtml format (www mode) and view the
       result in the web browser galeon.  The option --man guarantees that
       the man page is retrieved, even when a local file ls exists in the
       actual directory.

       sh# groffer --source 'man:roff(7)'

       Get the man page called roff in man section 7, decompress it, and
       print its unformatted content, its source code.

       sh# groffer --de-p --in --ap

       This is a set of abbreviated arguments, it is determined as

       sh# groffer --debug-params --intermediate-output --apropos

       sh# cat file.gz | groffer -Z -mfoo

       The file file.gz is sent to standard input, this is decompressed, and
       then this is transported to the groff intermediate output mode with‐
       out post-processing (groff option -Z), using macro package foo (groff
       option -m).

       sh# echo '\f(CBWOW!' |
       > groffer --x --bg red --fg yellow --geometry 200x100 -

       Display the word WOW! in a small window in constant-width bold font,
       using color yellow on red background.

Compatibility         top

       The groffer program is written in Perl, the Perl version during
       writing was v5.8.8.

       groffer provides its own parser for command-line arguments that is
       compatible to both POSIX getopts(1) and GNU getopt(1).  It can handle
       option arguments and file names containing white space and a large
       set of special characters.  The following standard types of options
       are supported.

       * The option consisting of a single minus - refers to standard input.

       * A single minus followed by characters refers to a single character
         option or a combination thereof; for example, the groffer short
         option combination -Qmfoo is equivalent to -Q -m foo.

       * Long options are options with names longer than one character; they
         are always preceded by a double minus.  An option argument can
         either go to the next command-line argument or be appended with an
         equal sign to the argument; for example, --long=arg is equivalent
         to --long arg.

       * An argument of -- ends option parsing; all further command-line
         arguments are interpreted as filespec parameters, i.e. file names
         or constructs for searching man pages).

       * All command-line arguments that are neither options nor option
         arguments are interpreted as filespec parameters and stored until
         option parsing has finished.  For example, the command line

         sh# groffer file1 -a -o arg file2

         is equivalent to

         sh# groffer -a -o arg -- file1 file2

       The free mixing of options and filespec parameters follows the GNU
       principle.  That does not fulfill the strange option behavior of
       POSIX that ends option processing as soon as the first non-option
       argument has been reached.  The end of option processing can be
       forced by the option “--” anyway.

Authors         top

       groffer was written by Bernd Warken ⟨⟩.

See Also         top

       groff(1), troff(1)
              Details on the options and environment variables available in
              groff; all of them can be used with groffer.

              This program tries to guess the necessary groff command-line
              options from the input and the groffer options.

              Documentation of the groff language.

              Documentation on the groff characters, special characters, and

              Documentation on the groff macro files.

              Documentation on the groff intermediate output before the run
              of a postprocessor.  (ditroff output).  This can be run by the
              groff or groffer option -Z.

       man(1) The standard program to display man pages.  The information
              there is only useful if it is the man page for GNU man.  Then
              it documents the options and environment variables that are
              supported by groffer.

              Viewers for groffer's x mode.

       gs(1)  Viewers for groffer's ps mode.

       ggv(1) Viewers for groffer's pdf mode.

       kdvi(1), xdvi(1), dvilx(1)
              Viewers for groffer's dvi mode.

              Web-browsers for groffer's html, xhtml, or www mode.

              Standard pager program for the tty mode.

       xz(1)  The decompression programs supported by groffer.

COLOPHON         top

       This page is part of the groff (GNU troff) project.  Information
       about the project can be found at 
       ⟨⟩.  If you have a bug report for
       this manual page, see ⟨⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨⟩ on 2020-07-14.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-07-12.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to

groff           30 January 2020                    groffer(1)

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