Linux ul command

Updated: 11/06/2021 by Computer Hope
ul command

On Unix-like operating systems, the ul utility performs the underlining of text.

This page covers the Linux version of ul.


ul [-i] [-t terminal] [file ...]


The ul utility 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 file /etc/termcap is read to determine the appropriate sequences for underlining. If the terminal cannot underline, but can do standout mode (boldface, for example), then that is used instead. If the terminal can overstrike, or handles underlining automatically, ul degenerates to a level of operation equivalent to cat. If the terminal cannot underline, underlining is ignored. During the translation some other special characters also get translated; for example, tabs get expanded to spaces.

-i Underlining is indicated by a separate line containing appropriate dashes ‘-’; this is useful when you want to look at the underlining that is present in an nroff output stream on a terminal.
-t terminal Overrides the terminal type specified in the environment with terminal type terminal.


The LANG, LC_ALL, LC_CTYPE and TERM environment variables affect the execution of ul.


ul myfile.txt

Processes myfile.txt for the underlining of text.

cat — Output the contents of a file.
man — Display the manual page of a given command.
nroff — Format documents for terminal display or line-printer.