# How can I draw a line around text, but open on one side? [duplicate]

I'd like to do something similar to \boxed{whatever}, but with the box open one side. Something like the following.

\documentclass{article}

\begin{document}

$\overline{\underline{abc |}}$

\end{document}


which results in the following output (ugly, but conceptually close to what I want):

I suppose there is a simple way to do what I need, but I couldn't find it.

Like this ?

With a tcolorbox:

\documentclass{article}
\usepackage{tcolorbox}

\newtcbox{\boxed}{on line,colframe=black,colback=white,sharp corners,
before upper={\rule[-3pt]{0pt}{10pt}},boxrule=1pt,leftrule=0pt,
boxsep=0pt,left=2pt,right=1pt,top=1pt,bottom=.5pt}

\begin{document}

Quick brown fox \boxed{jumped} over the lazy dog.

\end{document}

\documentclass{article}

\begin{document}

$\begin{array}{@{}|@{\,}l@{}} \hline abc\\ \hline \end{array}\quad\mbox{or}\quad \begin{array}{@{}l@{\,}|@{}} \hline abc\\ \hline \end{array}$

\end{document}


\documentclass{article}
\usepackage{tikz}
\usepackage{parskip}
\setlength{\parskip}{15pt}
\newsavebox{\mybox}
\newcommand{\PutInsideOpenBox}[3][-,black]{\ifdefined\extraxskip\relax\else\xdef\extraxskip{1pt}\fi\ifdefined\extrayskip\relax\else\xdef\extrayskip{3.5pt}\fi\savebox{\mybox}{\vbox{\hbox{#3}}}\begin{tikzpicture}[outer sep=0,inner sep=0pt,baseline=#2]\node at ({\wd\mybox/2},{(\ht\mybox+\dp\mybox)/2}){\usebox{\mybox}};
\draw[#1]({-\extraxskip},{-\extrayskip})--({\wd\mybox+\extraxskip},{-\extrayskip})--({\wd\mybox+\extraxskip},{(\ht\mybox+\dp\mybox)+\extrayskip})--({-\extraxskip},{(\ht\mybox+\dp\mybox)+\extrayskip});\end{tikzpicture}}
\begin{document}

$\PutInsideOpenBox{0pt}{ abc }$

In text: $$\PutInsideOpenBox[-,thick,red]{0pt}{AbcD}$$ that will expand in two lines and we will see that the baselineskip is slightly increased

Increasing borders:
\def\extraxskip{3pt}
\def\extrayskip{6pt}

In text: $$\PutInsideOpenBox[-,thick,red]{0pt}{AbcD}$$ that will expand in two lines and we will see that the baselineskip is enough increased

An equation:

$\PutInsideOpenBox{2.5pt}{f(x)}=x\cdot \PutInsideOpenBox[-,blue]{2.5pt}{(y+1)}$

\end{document}


With fbox package:

\documentclass{article}
\usepackage{fbox}

\begin{document}

\fbox[trb]{abc} \fbox[tlb]{abc}

\end{document}