--- name: "groff" section: "1" platform: "linux" package: "groff" version: "1.24.2-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/groff" --- # groff(1) front end to the GNU roff document formatting system ## Name groff - front end to the GNU *roff* document formatting system ## Synopsis **groff** \[**-abcCeEgGijklNpRsStUVXzZ**\] \[**-d** *ctext*\] \[**-d** *string***=** *text*\] \[**-D** *fallback-encoding*\] \[**-f** *font-family*\] \[**-F** *font-directory*\] \[**-I** *inclusion-directory*\] \[**-K** *input-encoding*\] \[**-L** *spooler-argument*\] \[**-m** *macro-package*\] \[**-M** *macro-directory*\] \[**-n** *page-number*\] \[**-o** *page-list*\] \[**-P** *postprocessor-argument*\] \[**-r** *cnumeric-expression*\] \[**-r** *register***=** *numeric-expression*\] \[**-T** *output-device*\] \[**-w** *warning-category*\] \[**-W** *warning-category*\] \[*file* ...\] **groff** **-h** **groff** **--help** **groff** **-v** \[*option* ...\] \[*file* ...\] **groff** **--version** \[*option* ...\] \[*file* ...\] ## Description *groff* is the primary front end to the GNU *roff* document formatting system. GNU *roff* is a typesetting system that reads plain text input that includes formatting commands to produce output in PostScript, PDF, HTML, or other formats, or for display to a terminal. Formatting commands can be low-level typesetting primitives, macros from a supplied package, or user-defined macros. All three approaches can be combined. If no *file* operands are specified, or if *file* is “**-**”, *groff* reads the standard input stream. A reimplementation and extension of *troff* and other programs from AT&T Unix, *groff* is widely available on POSIX and other systems owing to its long association with Unix manuals, including man pages. It and its predecessor have produced several best-selling software engineering texts. *groff* can create typographically sophisticated documents while consuming minimal system resources. Like its predecessor “troff”, the term “groff” affords two popular pronunciations: as one syllable (like the surname), rhyming with “trough”, or as “jee-roff”, in analogy to the Bell Labs pronunciation “tee-roff”. Little risk of confusion exists; use whichever suits you. The *groff* command orchestrates the execution of preprocessors, the transformation of input documents into a device-independent page description language, and the production of output from that language. ## Options **-h** and **--help** display a usage message and exit. Because *groff* is intended to subsume most users' direct invocations of the [*troff*(1)](/troff/1.md) formatter, the two programs share a set of options. However, *groff* has some options that *troff* does not share, and others which *groff* interprets differently. At the same time, not all valid *troff* options can be given to *groff*. ### *groff*-specific options The following options either do not exist in GNU *troff* or are interpreted differently by *groff*. - **-D** *enc* Use *enc* as [*preconv*(1)](/preconv/1.md)'s fallback input encoding; implies **-k**. - **-e** Run [*eqn*(1)](/eqn/1.md) preprocessor. - **-g** Run [*grn*(1)](/grn/1.md) preprocessor. - **-G** Run [*grap*(1)](/grap/1.md) preprocessor; implies **-p**. - **-I** *dir* Works as *troff*'s option (see below), but also implies **-g** and **-s**. *groff* passes **-I** options and their arguments to [*soelim*(1)](/soelim/1.md), [*troff*(1)](/troff/1.md), and output drivers; with the option letter changed to **-M**, it passes the same arguments to [*grn*(1)](/grn/1.md). - **-j** Run [*chem*(1)](/chem/1.md) preprocessor; implies **-p**. - **-k** Run [*preconv*(1)](/preconv/1.md) preprocessor. Refer to its man page for its behavior if neither of *groff*'s **-K** or **-D** options is also specified. - **-K** *enc* Set input encoding used by [*preconv*(1)](/preconv/1.md) to *enc*; implies **-k**. - **-l** Send the output to a spooler program for printing. The “**print**” directive in the device description file specifies the default command to be used; see [*groff\_font*(5)](/groff_font/5.md). If no such directive is present for the output device, this option is ignored. See options **-L** and **-X**. - **-L** *arg* Pass *arg* to the print spooler. If multiple *arg*s are required, pass each with a separate **-L** option. *groff* does not prefix an option dash to *arg* before passing it to the spooler. - **-M** Works as *troff*'s option (see below), but is also passed to [*eqn*(1)](/eqn/1.md), [*grap*(1)](/grap/1.md), and [*grn*(1)](/grn/1.md). - **-N** Prohibit newlines between *eqn* delimiters: pass **-N** to [*eqn*(1)](/eqn/1.md). - **-p** Run [*pic*(1)](/pic/1.md) preprocessor. - **-P** *arg* Pass *arg* to the postprocessor. If multiple *arg*s are required, pass each with a separate **-P** option. *groff* does not prefix an option dash to *arg* before passing it to the postprocessor. - **-R** Run [*refer*(1)](/refer/1.md) preprocessor. No mechanism is provided for passing arguments to it; most *refer* options have equivalent language elements that can be specified within the document. - **-s** Run [*soelim*(1)](/soelim/1.md) preprocessor. - **-S** Enable safer mode and ignore any subsequent **-U** option. *groff* passes the **-S** option to [*pic*(1)](/pic/1.md) and [*troff*(1)](/troff/1.md). - **-t** Run [*tbl*(1)](/tbl/1.md) preprocessor. - **-T** *dev* Prepare output for device *dev.* *groff* passes the **-T** option and its argument to *troff*, then (unless the **-Z** option is used) runs an output driver to convert *troff*'s output to a form appropriate for *dev*; see subsection “Output devices” below. - **-U** Operate in unsafe mode. *groff* passes the **-U** option to [*pic*(1)](/pic/1.md) and [*troff*(1)](/troff/1.md). - **--version** **-v** Write version information for *groff* and all programs run by it to the standard output stream; that is, the given command line is processed in the usual way, passing **-v** to the formatter and any pre- or postprocessors invoked. - **-V** Output the pipeline that *groff* would run to the standard output stream and exit. If given more than once, *groff* both writes the pipeline to the standard error stream and runs it. - **-X** Use [*gxditview*(1)](/gxditview/1.md) instead of the usual postprocessor to (pre)view a document on an X11 display. Combining this option with “**-T ps**” uses the font metrics of the PostScript device, whereas the “**-T X75**”, “**-T X75-12**” “**-T X100**”, and “**-T X100-12**” options use the metrics of X11 fonts. - **-Z** Disable postprocessing. *troff* output appears on the standard output stream (unless suppressed with **-z**); see [*groff\_out*(5)](/groff_out/5.md) for a description of this format. ### Transparent options The following options are passed as-is to the formatter program [*troff*(1)](/troff/1.md) and described in more detail in its man page. - **-a** Generate a plain text approximation of the typeset output. - **-b** Write a backtrace to the standard error stream on each error or warning. - **-c** Start with color output disabled. - **-C** Enable AT&T *troff* compatibility mode; implies **-c**. - **-d** *ctext* **-d** *string***=***text* Define string. - **-E** Inhibit *troff* error messages; implies **-Ww**. - **-f** *fam* Set default font family. - **-F** *dir* Search in directory *dir* for the selected output device's directory of device and font description files. - **-i** Process standard input after the specified input files. - **-I** *dir* Search *dir* for input files. - **-m** *mac* Read macro package *mac* before input. *groff* passes **-m** options and their arguments to [*eqn*(1)](/eqn/1.md), [*grap*(1)](/grap/1.md), and [*grn*(1)](/grn/1.md). - **-M** *dir* Search directory *dir* for macro files. *groff* passes **-M** options and their arguments to [*eqn*(1)](/eqn/1.md), [*grap*(1)](/grap/1.md), and [*grn*(1)](/grn/1.md). - **-n** *num* Begin numbering pages at *num.* - **-o** *list* Output only pages in *list*. - **-r** *cnumeric-expression* **-r** *register***=***numeric-expression* Define register. - **-S** Enable safer mode and ignore any subsequent **-U** option. - **-U** Operate in unsafe mode. - **-w** *cat* **-W** *cat* Enable and inhibit, respectively, warnings in category *cat.* - **-z** Suppress formatted device-independent output of *troff*. ## Usage The architecture of the GNU *roff* system follows that of other device-independent *roff* implementations, comprising preprocessors, macro packages, output drivers (or “postprocessors”), and a suite of utilities, with the formatter program [*troff*(1)](/troff/1.md) at its heart. See [*roff*(7)](/roff/7.md) for a survey of how a *roff* system works. The front end programs available in the GNU *roff* system make it easier to use than traditional *roff*s that required the construction of pipelines or use of temporary files to carry a source document from maintainable form to device-ready output. The discussion below summarizes the constituent parts of the GNU *roff* system. It complements [*roff*(7)](/roff/7.md) with *groff*-specific information. ### Getting started Those who prefer to learn by experimenting or are desirous of rapid feedback from the system may wish to start with a “Hello, world!” document. ``` $ echo "Hello, world!" | groff -Tascii | sed '/^$/d' Hello, world! ``` We used a [*sed*(1)](/sed/1.md) command only to eliminate the 65 blank lines that would otherwise flood the terminal screen. (*roff* systems were developed in the days of paper-based terminals with 66 lines to a page.) Today's users may prefer output to a UTF-8-capable terminal. ``` $ echo "Hello, world!" | groff -Tutf8 | sed '/^$/d' ``` Producing PDF, HTML, or TeX's DVI is also straightforward. The hard part may be selecting a viewer program for the output. ``` $ echo "Hello, world!" | groff -Tpdf > hello.pdf $ evince hello.pdf $ echo "Hello, world!" | groff -Thtml > hello.html $ firefox hello.html $ echo "Hello, world!" | groff -Tdvi > hello.dvi $ xdvi hello.dvi ``` ### Using *groff* as a REPL Those with a programmer's bent may be pleased to know that they can use *groff* in a read-evaluate-print loop (REPL). Doing so can be handy to verify one's understanding of the formatter's behavior and/or the syntax it accepts. Turning on all warnings with **-ww** can aid this goal. ``` $ groff -ww -Tutf8 \# This is a comment. Let's define a register. .nr a 1 \# Do integer arithmetic with operators evaluated left-to-right. .nr b \n[a]+5/2 \# Let's get the result on the standard error stream. .tm \n[b] 3 \# Now we'll define a string. .ds name Leslie\" This is another form of comment. .nr b (\n[a] + (7/2)) \# Center the next two text input lines. .ce 2 Hi, \*[name]. Your secret number is \n[b]. \# We will see that the division rounded toward zero. It is \# Here's an if-else control structure. .ie (\n[b] % 2) odd. .el even. \# This trick sets the page length to the current vertical \# position, so that blank lines don't spew when we're done. .pl \n[nl]u Hi, Leslie. Your secret number is 4. It is even. ``` ### Paper format The formatter reads the device description file *DESC* for the selected output device when it starts; page dimensions declared there are used if present. *groff*'s build process configures a default page format and writes it to typesetters' *DESC* files. This installation defaults to “**A4**”. If the *DESC* file lacks this information, the formatter and output driver use a page length of **“**11i**”** (eleven inches) for compatibility with AT&T *troff*. See [*groff\_font*(5)](/groff_font/5.md). In the formatter, the **pl** request changes the page length, but macro packages often do not support alteration of the paper format within a document. One might, for instance, want to switch between portrait and landscape orientations. Macro packages lack a consistent approach to configuration of parameters dependent on the paper format; some, like *ms*, benefit from a preamble in the document prior to the first macro call, while others, like *mm*, instead require the specification of registers on the command line, or otherwise before its macro file is interpreted, to configure page dimensions. Output drivers for typesetters also recognize command-line options **-p** to override the default page dimensions and **-l** to use landscape orientation. The output driver's man page, such as [*grops*(1)](/grops/1.md), may be helpful. *groff*'s “**-d paper**” command-line option is a convenient means of setting the paper format; see [*groff\_tmac*(5)](/groff_tmac/5.md). Combine it with appropriate **-P** options for the output driver, overriding its defaults. The following command formats for PostScript on A4 paper in landscape orientation. ``` $ groff -T ps -d paper=a4l -P -pa4 -P -l -ms my.ms >my.ps ``` ### Front end The *groff* program wraps [*troff*(1)](/troff/1.md), allowing one to specify preprocessors via command-line options and running the appropriate output driver for the selected output device. This convenience avoids the manual construction of pipelines or management of temporary files required of users of traditional [*roff*(7)](/roff/7.md) systems. Use [*grog*(1)](/grog/1.md) to infer an appropriate *groff* command line to format a document. ### Language Input to a *roff* system is in plain text interleaved with control lines and escape sequences. The combination constitutes a document in one of a family of languages we also call *roff*; see [*roff*(7)](/roff/7.md) for background. An overview of GNU *roff* language syntax and features, including lists of all supported escape sequences, requests, and predefined registers, can be found in [*groff*(7)](/groff/7.md). GNU *roff* extensions to the AT&T *troff* language, a common subset of *roff* dialects extant today, are detailed in [*groff\_diff*(7)](/groff_diff/7.md). ### Preprocessors A preprocessor interprets a domain-specific language that produces *roff* language output. Frequently, such input is confined to sections or regions of *roff* input (bracketed with macro calls specific to each preprocessor), which it replaces. Preprocessors therefore often interpret a subset of *roff* syntax along with their own language. GNU *roff* provides reimplementations of most preprocessors familiar to users of AT&T *troff*; these routinely have extended features and/or require GNU *troff* to format their output.\ | | | | --- | --- | | *tbl* | lays out tables; | | *eqn* | typesets mathematics; | | *pic* | draws diagrams; | | *refer* | processes bibliographic references; | | *soelim* | preprocesses “sourced” input files; | | *grn* | renders diagrams; | | *chem* | draws chemical structural formulæ using *pic*;*"*generic | | *gperl* | populates *groff* registers and strings using | | *glilypond* | embeds *LilyPond* sheet music; and | | *gpinyin* | eases Mandarin Chinese input using Hanyu Pinyin. | A preprocessor unique to GNU *roff* is [*preconv*(1)](/preconv/1.md), which converts various input encodings to something GNU *troff* can understand. When used, it is run before any other preprocessors. Most preprocessors enclose content between a pair of characteristic tokens. Such a token must occur at the beginning of an input line and use the dot control character. Spaces and tabs must not follow the control character or precede the end of the input line. Deviating from these rules defeats a token's recognition by the preprocessor. Tokens are generally preserved in preprocessor output and interpreted as macro calls subsequently by *troff*. The *ideal* preprocessor is not yet available in *groff*. | | | | | --- | --- | --- | | preprocessor | starting token | ending token | | *chem* | | | | *eqn* | | | | *grap* | | | | *grn* | | | | *ideal* | | | | | | | | *pic* | | | | | | | | | | | | *refer* | | | | *tbl* | | | | *glilypond* | | | | *gperl* | | | | *gpinyin* | | | ### Macro packages Macro files are *roff* input files designed to produce no output themselves but instead ease the preparation of other *roff* documents. When a macro file is installed at a standard location and suitable for use by a general audience, it is termed a *macro package*.\ The **-m** option loads a macro package prior to any *roff* input documents, and after performing any string and register assignments directed by **-d** and **-r** options. The GNU *roff* system implements most well-known macro packages for AT&T *troff* in a compatible way and extends them. These have one- or two-letter names arising from intense practices of naming economy in early Unix culture, a laconic approach that led to many of the packages being identified in general usage with the *nroff* and *troff* option letter used to invoke them, sometimes to punning effect, as with “man” (short for “manual”), and even with the option dash, as in the case of the *s* package, much better known as *ms* or even *-ms*. Macro packages serve a variety of purposes. Some are “full-service” packages, adopting responsibility for page layout among other fundamental tasks, and defining their own lexicon of macros for document composition; each such package stands alone and a given document can use at most one. - *an* is used to compose man pages in the format originating in Version 7 Unix (1979); see [*groff\_man*(7)](/groff_man/7.md). It can be specified on the command line as **-man**. - *doc* is used to compose man pages in the format originating in 4.3BSD-Reno (1990); see [*groff\_mdoc*(7)](/groff_mdoc/7.md). It can be specified on the command line as **-mdoc**. - *e* is the Berkeley general-purpose macro suite, developed as an alternative to AT&T's *s*; see [*groff\_me*(7)](/groff_me/7.md). It can be specified on the command line as **-me**. - *m* implements the format used by the second-generation AT&T macro suite for general documents, a successor to *s*; see [*groff\_mm*(7)](/groff_mm/7.md). It can be specified on the command line as **-mm**. - *om* (invariably called “mom”) is a modern package written by Peter Schaffter specifically for GNU *roff*. Consult the *mom* HTML manual ⟨file://\\:/usr/\\:\\%share/\\:\\%doc/\\:\\%groff\\-1.24.2/\\:\\%html/\\:mom/\\:toc\\:.html⟩ for extensive documentation. She—for *mom* takes the female pronoun—can be specified on the command line as **-mom**. - *s* is the original AT&T general-purpose document format; see [*groff\_ms*(7)](/groff_ms/7.md). It can be specified on the command line as **-ms**. Others are supplemental. For instance, *andoc* is a wrapper package specific to GNU *roff* that recognizes whether a document uses *man* or *mdoc* format and loads the corresponding macro package. It can be specified on the command line as **-mandoc**. A [*man*(1)](/man/1.md) librarian may use this macro file to delegate loading of the correct macro package; it is thus unnecessary for *man* itself to scan the contents of a document to decide the issue. Many macro files augment the function of the full-service packages, or of *roff* documents that do not employ such a package—the latter are sometimes characterized as “raw”. These auxiliary packages are described, along with details of macro file naming and placement, in [*groff\_tmac*(5)](/groff_tmac/5.md). ### Formatters The formatter, the program that interprets *roff* language input, is [*troff*(1)](/troff/1.md). It provides the features of the AT&T *troff* and *nroff* programs as well as many extensions. The command-line option **-C** switches *troff* into *compatibility mode*, which tries to emulate AT&T *troff* as closely as is practical to enable the formatting of documents written for the older system. A shell script, [*nroff*(1)](/nroff/1.md), emulates the behavior of AT&T *nroff*. It attempts to correctly encode the output based on the locale, relieving the user of the need to specify an output device with the **-T** option and is therefore convenient for use with terminal output devices, described in the next subsection. GNU *troff* generates output in a device-independent, but not device-agnostic, page description language detailed in [*groff\_out*(5)](/groff_out/5.md). ### Output devices *troff* output is formatted for a particular *output device*, typically specified by the **-T** option to the formatter or a front end. If neither this option nor the *GROFF\_TYPESETTER* environment variable is used, the default output device is **ps**. An output device may be any of the following. - **ascii** for terminals using the ISO 646 1991:IRV character set and encoding, also known as US-ASCII. - **dvi** for TeX DVI format. - **html** **xhtml** for HTML and XHTML output, respectively. - **latin1** for terminals using the ISO Latin-1 (8859-1) character set and encoding. - **lbp** for Canon CaPSL printers (LBP-4 and LBP-8 series laser printers). - **lj4** for HP LaserJet4-compatible (or other PCL5-compatible) printers. - **pdf** for PDF output. - **ps** for PostScript output. - **utf8** for terminals using the ISO 10646 (“Unicode”) character set in UTF-8 encoding. - **X75** for previewing with *gxditview* using 75 dpi resolution and a 10-point base type size. - **X75-12** for previewing with *gxditview* using 75 dpi resolution and a 12-point base type size. - **X100** for previewing with *gxditview* using 100 dpi resolution and a 10-point base type size. - **X100-12** for previewing with *gxditview* using 100 dpi resolution and a 12-point base type size. ### Postprocessors Any program that interprets the output of GNU *troff* is a postprocessor. The postprocessors provided by GNU *roff* are *output drivers*, which prepare a document for viewing or printing. Postprocessors for other purposes, such as page resequencing or statistical measurement of a document, are conceivable. An output driver supports one or more output devices, each with its own device description file. A device determines its postprocessor with the **postpro** directive in its device description file; see [*groff\_font*(5)](/groff_font/5.md). The **-X** option overrides this selection, causing *gxditview* to serve as the output driver. - [*grodvi*(1)](/grodvi/1.md) provides **dvi**. - [*grohtml*(1)](/grohtml/1.md) provides **html** and **xhtml**. - [*grolbp*(1)](/grolbp/1.md) provides **lbp**. - [*grolj4*(1)](/grolj4/1.md) provides **lj4**. - [*gropdf*(1)](/gropdf/1.md) provides **pdf**. - [*grops*(1)](/grops/1.md) provides **ps**. - [*grotty*(1)](/grotty/1.md) provides **ascii**, **latin1**, and **utf8**. - [*gxditview*(1)](/gxditview/1.md) provides **X75**, **X75-12**, **X100**, and **X100-12**, and additionally can preview **ps**. ### Utilities GNU *roff* includes a suite of utilities. - [*gdiffmk*(1)](/gdiffmk/1.md) marks differences between a pair of *roff* input files. - [*grog*(1)](/grog/1.md) infers the *groff* command a document requires. Several utilities prepare descriptions of fonts, enabling the formatter to use them when producing output for a given device. - [*addftinfo*(1)](/addftinfo/1.md) adds information to AT&T *troff* font description files to enable their use with GNU *troff*. - [*afmtodit*(1)](/afmtodit/1.md) creates font description files for PostScript Type 1 fonts. - [*pfbtops*(1)](/pfbtops/1.md) translates a PostScript Type 1 font in PFB (Printer Font Binary) format to PFA (Printer Font ASCII), which can then be interpreted by *afmtodit*. - [*hpftodit*(1)](/hpftodit/1.md) creates font description files for the HP LaserJet 4 family of printers. - [*tfmtodit*(1)](/tfmtodit/1.md) creates font description files for the TeX DVI device. - [*xtotroff*(1)](/xtotroff/1.md) creates font description files for X Window System core fonts. A trio of tools transform material constructed using *roff* preprocessor languages into graphical image files. - [*eqn2graph*(1)](/eqn2graph/1.md) converts an *eqn* equation into a cropped image. - [*grap2graph*(1)](/grap2graph/1.md) converts a *grap* diagram into a cropped image. - [*pic2graph*(1)](/pic2graph/1.md) converts a *pic* diagram into a cropped image. Another set of programs works with the bibliographic data files used by the [*refer*(1)](/refer/1.md) preprocessor. - [*indxbib*(1)](/indxbib/1.md) makes inverted indices for bibliographic databases, speeding lookup operations on them. - [*lkbib*(1)](/lkbib/1.md) searches the databases. - [*lookbib*(1)](/lookbib/1.md) interactively searches the databases. ## Exit status *groff* exits successfully (with status **0**) if either of the options **-h** or **--help** is specified, status **2** if the program cannot interpret its command-line arguments, and status **1** if it encounters an error during operation. Otherwise, *groff* runs a pipeline to process its input; if all commands within the pipeline exit successfully, *groff* does likewise. If not, *groff*'s exit status encodes a summary of problems encountered, setting bit 2 if a command exited with a failure status, bit 3 if a command was terminated with a signal, and bit 4 if a command could not be executed. (Thus, if all three misfortunes befall one's pipeline, *groff* exits with status 2^2 + 2^3 + 2^4 = 4+8+16 = 28.) To troubleshoot pipeline problems, re-run the *groff* command with the **-V** option and break the reported pipeline down into separate stages, inspecting the exit status of, and diagnostic messages emitted by, each command. ## Environment Environment variables in the host system affect the behavior of programs supplied by *groff* as follows. Normally, the path separator in environment variables ending with *PATH* is the colon; this may vary depending on the operating system. For example, Windows uses a semicolon instead. - *GROFF\_BIN\_PATH* Locate *groff* commands in these directories, followed by those in *PATH*. If not set, the installation directory of GNU *roff* executables, */usr/bin*, is searched before *PATH*. - *GROFF\_COMMAND\_PREFIX* Apply a prefix to certain GNU *roff* commands. *groff* can be configured at compile time to apply a prefix to the names of programs it provides that had counterparts in AT&T *troff*, so that name collisions are avoided at run time. The default prefix is empty. - When used, this prefix is conventionally the letter “g”. For example, GNU *troff* would be installed as *gtroff*. Besides *troff*, the prefix applies to the formatter wrapper *nroff*; the preprocessors *eqn*, *grn*, *pic*, *refer*, *tbl*, and *soelim*; and the utilities *indxbib* and *lookbib*. - *GROFF\_ENCODING* Specify the assumed character encoding of the input. *groff* passes its value as an argument to [*preconv*(1)](/preconv/1.md) preprocessor's **-e** option. This variable's existence implies the *groff* option **-k**. If set but empty, *groff* runs *preconv* without an **-e** option. *groff*'s **-K** option overrides *GROFF\_ENCODING*. - *GROFF\_FONT\_PATH* Seek the selected output device's directory of device and font description files in this list of directories. See [*troff*(1)](/troff/1.md) and [*groff\_font*(5)](/groff_font/5.md). - *GROFF\_TMAC\_PATH* Seek macro packages in this list of directories. See [*troff*(1)](/troff/1.md) and [*groff\_tmac*(5)](/groff_tmac/5.md). - *GROFF\_TMPDIR* Create temporary files in this directory. If not set, but *TMPDIR* is, the latter is used instead. On Windows systems, if neither of the foregoing are set, the environment variables *TMP* and *TEMP* (in that order) are checked also. Otherwise, temporary files are created in */tmp*. The [*refer*(1)](/refer/1.md), [*grohtml*(1)](/grohtml/1.md), and [*grops*(1)](/grops/1.md) commands use temporary files. - *GROFF\_TYPESETTER* Set the default output device. If empty or not set, **ps** is used. The **-T** option overrides *GROFF\_TYPESETTER*. - *SOURCE\_DATE\_EPOCH* Declare a time stamp (expressed as seconds since the Unix epoch) to use as the output creation time stamp in place of the current time. The time is converted to human-readable form using [*gmtime*(3)](/gmtime/3.md) and [*asctime*(3)](/asctime/3.md) when the formatter starts up and stored in registers usable by documents and macro packages. - *TZ* Declare the time zone to use when converting the current time to human-readable form; see [*tzset*(3)](/tzset/3.md). If *SOURCE\_DATE\_EPOCH* is used, it is always converted to human-readable form using UTC. ## Examples *roff* systems are best known for formatting man pages. A [*man*(1)](/man/1.md) librarian program, having located a page, might render it with a *groff* command. ``` groff -t -man -Tutf8 /usr/share/man/man1/groff.1 ``` The librarian will also pipe the output through a pager, which might not interpret terminal escape sequences *groff* emits for boldface, underlining, italics, or hyperlinking; see section “Limitations” below. To process a *roff* input file using the preprocessors *tbl* and *pic* and the *me* macro package in the way to which AT&T *troff* users were accustomed, one would type (or script) a pipeline. - ``` pic foo.me | tbl | troff -me -Tutf8 | grotty ``` Shorten this pipeline to an equivalent command using *groff*. - ``` groff -p -t -me -T utf8 foo.me ``` An even easier way to do this is to use [*grog*(1)](/grog/1.md) to guess the preprocessor and macro options and execute the result by using the command substitution feature of the shell. - ``` $(grog -Tutf8 foo.me) ``` Each command-line option to a postprocessor must be specified with any required leading dashes “**-**” because *groff* passes the arguments as-is to the postprocessor; this permits arbitrary arguments to be transmitted. For example, to pass a title to the *gxditview* postprocessor, the shell commands ``` groff -X -P -title -P 'trial run' mydoc.t ``` and ``` groff -X -Z mydoc.t | gxditview -title 'trial run' - ``` are equivalent. ## Limitations When paging output for the **ascii**, **latin1**, and **utf8** devices, programs like [*more*(1)](/more/1.md) and [*less*(1)](/less/1.md) may require command-line options to correctly handle some terminal escape sequences; see [*grotty*(1)](/grotty/1.md). ## Installation directories GNU *roff* installs files in varying locations depending on its compile-time configuration. On this installation, the following locations are used. - */usr/lib/X11/app-defaults* Application defaults directory for [*gxditview*(1)](/gxditview/1.md). - */usr/bin* Directory containing *groff*'s executable commands. - */usr/share/groff/1.24.2/eign* List of common words for [*indxbib*(1)](/indxbib/1.md). - */usr/share/groff/1.24.2* Directory for data files. - */usr/dict/papers/Ind* Default index for [*lkbib*(1)](/lkbib/1.md) and [*refer*(1)](/refer/1.md). - */usr/share/doc/groff-1.24.2* Documentation directory. - */usr/share/doc/groff-1.24.2/examples* Example directory. - */usr/share/groff/1.24.2/font* Font directory. - */usr/share/doc/groff-1.24.2/html* HTML documentation directory. - */usr/lib/font* Legacy font directory. - */usr/share/groff/site-font* Local font directory. - */usr/share/groff/site-tmac* Local macro package (*tmac* file) directory. - */usr/share/groff/1.24.2/tmac* Macro package (*tmac* file) directory. - */usr/share/groff/1.24.2/oldfont* Font directory for compatibility with old versions of *groff*; see [*grops*(1)](/grops/1.md). - */usr/share/doc/groff-1.24.2/pdf* PDF documentation directory. ### *groff* macro directory Most macro files supplied with GNU *roff* are stored in */usr/share/groff/1.24.2/tmac* for the installation corresponding to this document. As a rule, multiple directories are searched for macro files; see [*troff*(1)](/troff/1.md). For a catalog of macro files GNU *roff* provides, see [*groff\_tmac*(5)](/groff_tmac/5.md). ### *groff* device and font description directory Device and font description files supplied with GNU *roff* are stored in */usr/share/groff/1.24.2/font* for the installation corresponding to this document. As a rule, multiple directories are searched for device and font description files; see [*troff*(1)](/troff/1.md). For the formats of these files, see [*groff\_font*(5)](/groff_font/5.md). ## Availability Obtain links to *groff* releases for download, its source repository, discussion mailing lists, a support ticket tracker, and further information from the *groff* page of the GNU website ⟨http://\\:www\\:.gnu\\:.org/\\:software/\\:groff⟩. A free implementation of the *grap* preprocessor, written by Ted Faber ⟨faber@\\:lunabase\\:.org⟩, can be found at the *grap* website ⟨http://\\:www\\:.lunabase\\:.org/\\:\\\[ti\]faber/\\:Vault/\\:software/\\:grap/⟩. *groff* supports only this *grap*. ## Authors *groff* (both the front-end command and the overall system) was primarily written by James Clark ⟨jjc@\\:jclark\\:.com⟩. Contributors to this document include Clark, Trent A. Fisher, Werner Lemberg ⟨wl@gnu.org⟩, Bernd Warken ⟨groff\\-bernd.warken\\-72@\\:web\\:.de⟩, and G. Branden Robinson ⟨g.branden\\:.robinson@\\:gmail\\:.com⟩. ## See also *Groff: The GNU Implementation of troff*, by Trent A. Fisher and Werner Lemberg, is the primary *groff* manual. You can browse it interactively with “info groff”. A list of all *groff* man pages follows. A few (*grohtml*, *gropdf*, *gxditview*, and *xtotroff*) will be unavailable if their corresponding programs were disabled during compilation. - Introduction, history, and further reading: [*roff*(7)](/roff/7.md) - Viewer for *groff* (and AT&T device-independent *troff*) documents: [*gxditview*(1)](/gxditview/1.md) - Preprocessors: [*chem*(1)](/chem/1.md), [*eqn*(1)](/eqn/1.md), [*neqn*(1)](/neqn/1.md), [*glilypond*(1)](/glilypond/1.md), [*grn*(1)](/grn/1.md), [*preconv*(1)](/preconv/1.md), [*gperl*(1)](/gperl/1.md), [*pic*(1)](/pic/1.md), [*gpinyin*(1)](/gpinyin/1.md), [*refer*(1)](/refer/1.md), [*soelim*(1)](/soelim/1.md), [*tbl*(1)](/tbl/1.md) - Macro packages: [*groff\_hdtbl*(7)](/groff_hdtbl/7.md), [*groff\_man*(7)](/groff_man/7.md), [*groff\_man\_style*(7)](/groff_man_style/7.md), [*groff\_mdoc*(7)](/groff_mdoc/7.md), [*groff\_me*(7)](/groff_me/7.md), [*groff\_mm*(7)](/groff_mm/7.md), [*groff\_mmse*(7)](/groff_mmse/7.md), [*groff\_mom*(7)](/groff_mom/7.md), [*groff\_ms*(7)](/groff_ms/7.md), [*groff\_rfc1345*(7)](/groff_rfc1345/7.md), [*groff\_trace*(7)](/groff_trace/7.md), [*groff\_www*(7)](/groff_www/7.md) - Bibliographic database management tools: [*indxbib*(1)](/indxbib/1.md), [*lkbib*(1)](/lkbib/1.md), [*lookbib*(1)](/lookbib/1.md) - Language, conventions, and GNU extensions: [*groff*(7)](/groff/7.md), [*groff\_char*(7)](/groff_char/7.md), [*groff\_diff*(7)](/groff_diff/7.md), [*groff\_font*(5)](/groff_font/5.md), [*groff\_tmac*(5)](/groff_tmac/5.md) - Device-independent page description language: [*groff\_out*(5)](/groff_out/5.md) - Formatter program: [*troff*(1)](/troff/1.md) - Formatter wrappers: [*nroff*(1)](/nroff/1.md), [*mmroff*(1)](/mmroff/1.md), [*pdfmom*(1)](/pdfmom/1.md) - Postprocessors for output devices: [*grodvi*(1)](/grodvi/1.md), [*grohtml*(1)](/grohtml/1.md), [*grolbp*(1)](/grolbp/1.md), [*grolj4*(1)](/grolj4/1.md), [*gropdf*(1)](/gropdf/1.md), [*grops*(1)](/grops/1.md), [*grotty*(1)](/grotty/1.md) - Font support utilities: [*addftinfo*(1)](/addftinfo/1.md), [*afmtodit*(1)](/afmtodit/1.md), [*hpftodit*(1)](/hpftodit/1.md), [*pfbtops*(1)](/pfbtops/1.md), [*tfmtodit*(1)](/tfmtodit/1.md), [*xtotroff*(1)](/xtotroff/1.md) - Graphics conversion utilities: [*eqn2graph*(1)](/eqn2graph/1.md), [*grap2graph*(1)](/grap2graph/1.md), [*pic2graph*(1)](/pic2graph/1.md) - Difference-marking utility: [*gdiffmk*(1)](/gdiffmk/1.md) - “groff guess” utility: [*grog*(1)](/grog/1.md)