DETROFF is a C++ program which makes a copy of a file from which all pairs of backspace+character have been removed.
Given the string of 8 characters:
where we are using "#" to represent a backspace, the returned string will be
This function was originally written for use in "cleaning up" MAN pages so that they would print properly. These MAN pages were formatted in the Paleolithic and Byzantine TROFF printing format. Although the files were text, and would seem to "print" correctly to the screen, an unholy mess would emerge if the same file was sent to the printer. This is because the screen handled the backspaces by backspacing, but most printers don't know anymore how to handle TROFF's backspaces, and so they just print them as blobs, instead of, say, spacing back.
Passages which are to be underlined were written so:
when what is meant is that "Text" is to be underlined if possible. Note that the seemingly equivalent
is NOT used. This is because, in the olden days, certain screen terminals could backspace, but would only display the new character, obliterating rather than overwriting the old one. This convention allows us to know that we want to delete "character" + Backspace, rather than Backspace + "character".
Passages which are meant to be in BOLDFACE are written so:
when what is meant is that "Ugly" is to be printed as boldly as possible. These boldface passages may also be cleaned up using the same rule of removing all occurrences of "character" + Backspace.
It is truly a fright to look at the text of one of these MAN pages with all the ugly Backspace's, which sometimes display as ^H or as a reverse-video bugsplat.
detroff old newwhere
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
DETROFF is available in a C++ version.
CR2CRLF, a C++ program which replaces carriage returns by carriage returns + line feeds.
CR2LF, a C++ program which reads a text file and replaces carriage returns by line feeds.
CRRM, a C++ program which removes all carriage returns from a file.
DEBLANK, a C++ program which makes a copy of a text file which contains no blank lines.
DECOMMENT, a C++ program which makes a copy of a text file which contains no "comment" lines (that begin with "#").
FILUM, a C++ library which performs various operations on files.
LF2CR, a C++ program which replaces linefeeds by carriage returns.
LF2CRLF, a C++ program which replaces linefeeds by carriage returns + line feeds.
LFRM, a C++ program which removes all linefeeds from a file.
REFORMAT, a FORTRAN90 program which reads a text file that contains only real values, and writes a copy which has a fixed number of real values on each line.
REWORD, a C++ program which reads a text file and writes a copy which has a fixed number of "words" per line.
UNCONTROL, a C++ program which makes a copy of a text file which contains no control characters.
WRAP, a C++ program which makes a copy of a text file in which no line is longer than a user-specified wrap length.
WRAP2, a C++ program which wraps long lines in a text file, but which wraps some lines "early", so as to avoid breaking words.
You can go up one level to the C++ source codes.