UL(1)                           User Commands                          UL(1)

NAME         top

       ul - do underlining

SYNOPSIS         top

       ul [options] [file...]

DESCRIPTION         top

       ul reads the named files (or standard input if none are given) and
       translates occurrences of underscores to the sequence which indicates
       underlining for the terminal in use, as specified by the environment
       variable TERM.  The terminfo database is read to determine the
       appropriate sequences for underlining.  If the terminal is incapable
       of underlining but is capable of a standout mode, then that is used
       instead.  If the terminal can overstrike, or handles underlining
       automatically, ul degenerates to cat(1).  If the terminal cannot
       underline, underlining is ignored.

OPTIONS         top

       -i, --indicated
              Underlining is indicated by a separate line containing
              appropriate dashes `-'; this is useful when you want to look
              at the underlining which is present in an nroff output stream
              on a crt-terminal.

       -t, -T, --terminal terminal
              Override the environment variable TERM with the specified
              terminal type.

       -V, --version
              Display version information and exit.

       -h, --help
              Display help text and exit.

ENVIRONMENT         top

       The following environment variable is used:

       TERM   The TERM variable is used to relate a tty device with its
              device capability description (see terminfo(5)).  TERM is set
              at login time, either by the default terminal type specified
              in /etc/ttys or as set during the login process by the user in
              their login file (see setenv(1)).

SEE ALSO         top

       colcrt(1), login(1), man(1), nroff(1), setenv(1), terminfo(5)

BUGS         top

       nroff usually outputs a series of backspaces and underlines
       intermixed with the text to indicate underlining.  No attempt is made
       to optimize the backward motion.

HISTORY         top

       The ul command appeared in 3.0BSD.

AVAILABILITY         top

       The ul command is part of the util-linux package and is available
       from Linux Kernel Archive 

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) project.  Information about the project can be found at 
       ⟨⟩.  If you have a
       bug report for this manual page, send it to  This page was obtained from the
       project's upstream Git repository 
       ⟨git://⟩ on
       2017-03-13.  If you discover any rendering problems in this HTML ver‐
       sion 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 man‐
       ual page), send a mail to

util-linux                     September 2011                          UL(1)