nroff(1)

Name
nroff - format documents with groff for TTY (terminal) devices

Synopsis
nroff [-bcCEhikpRStUVz] [-d ctext] [-d string= text] [-K fallback-encoding] [-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 ...]
nroff --help
nroff -v
nroff --version

Description
nroff formats documents written in the groff(7) language for typewriter-like devices such as terminal emulators. GNU nroff emulates the AT&T nroff command using groff(1). nroff generates output via grotty(1), groff's terminal output driver, which needs to know the character encoding scheme used by the device. Consequently, acceptable arguments to the -T option are ascii, latin1, utf8, and cp1047; any others are ignored. If neither the GROFF_TYPESETTER environment variable nor the -T command-line option (which overrides the environment variable) specifies a (valid) device, nroff consults the locale to select an appropriate output device. It first tries the locale(1) program, then checks several locale-related environment variables; see section “Environment” below. If all of the foregoing fail, -Tascii is implied.

The -b, -c, -C, -d, -E, -i, -m, -M, -n, -o, -r, -U, -w, -W, and -z options have the effects described in troff(1). -c and -h imply “-P-c” and “-P-h”, respectively; -c is also interpreted directly by troff. In addition, this implementation ignores the AT&T nroff options -e, -q, and -s (which are not implemented in groff). The options -k, -K, -p, -P, -R, -t, and -S are documented in groff(1). -V causes nroff to display the constructed groff command on the standard output stream, but does not execute it. -v and --version show version information about nroff and the programs it runs, while --help displays a usage message; all exit afterward.

Exit status
nroff exits with error status 2 if there was a problem parsing its arguments, with status 0 if any of the options -V, -v, --version, or --help were specified, and with the status of groff otherwise.

Environment
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
    is a colon-separated list of directories in which to search for the groff executable before searching in PATH. If unset, /data/data/com.termux/files/usr/bin is used.

GROFF_TYPESETTER
    specifies the default output device for groff.

LC_ALL
LC_CTYPE
LANG
LESSCHARSET
    are pattern-matched in this order for contents matching standard character encodings supported by groff in the event no -T option is given and GROFF_TYPESETTER is unset, or the values specified are invalid.

Files

/data/data/com.termux/files/usr/share/groff/1.23.0/tmac/tty-char.tmac
    defines fallback definitions of roff special characters. These definitions more poorly optically approximate typeset output than those of tty.tmac in favor of communicating semantic information. nroff loads it automatically.

Notes
Pager programs like more(1) and less(1) may require command-line options to correctly handle some output sequences; see grotty(1).

See also
groff(1), troff(1), grotty(1), locale(1), roff(7)