How do define a command that takes parameters like \verb?

Question

I would like to define a newcommand that takes one required parameter, but instead of passing it in using {...} as normal, to use a different parameter delineator like the \verb command does (e.g., \mycmd|args|). Trying to do this with a normal \newcommand definition seems to behave strangely.

Answer 1

If you do not want catcode sanitization:

\newcommand\myverb[1]%
    {\def\domyverb##1#1{ the argument was `##1'}%
     \domyverb}

and then use it as follows.

\myverb|test|

\myverb+test+

\myverb!test!

Answer 2

It mostly depends on what you want to do. If all you need is to use the argument "as is", then

\def\mycmd|#1|{...#1...}

will do. This doesn't check whether \mycmd is defined; if you need the check, then use

\makeatletter
\@ifdefinable\mycmd{%
  \def\mycmd|#1|{...#1...}%
}
\makeatother

If you need this to do "verbatim" things, the definition must be quite more complicated.