UL(1) User Commands UL(1)

ul - do underlining

ul [options] [file...]

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.

-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.

-h, --help

Display help text and exit.

-V, --version

Print version and exit.

The following environment variable is used:


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(3)).

The ul command appeared in 3.0BSD.

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.

colcrt(1), login(1), man(1), nroff(1), setenv(3), terminfo(5)

For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.

The ul command is part of the util-linux package which can be downloaded from Linux Kernel Archive https://www.kernel.org/pub/linux/utils/util-linux/.

2024-07-04 util-linux 2.40.2