colcrt --- filter nroff output for CRT previewing
colcrt [-] [-2] [file ...]
The colcrt utility provides virtual half-line and reverse line feed sequences for terminals without such capability, and on which overstriking is destructive. Half-line characters and underlining (changed to dashing `-') are placed on new lines in between the normal output lines. The following options are available: - Suppress all underlining. This option is especially useful for previewing allboxed tables from tbl(1). -2 Cause all half-lines to be printed, effectively double spacing the output. Normally, a minimal space output format is used which will suppress empty lines. The program never suppresses two consecutive empty lines, however. The -2 option is useful for sending output to the line printer when the output contains superscripts and subscripts which would otherwise be invisible.
The LANG, LC_ALL and LC_CTYPE environment variables affect the execution of colcrt as described in environ(7).
The colcrt utility exits 0 on success, and >0 if an error occurs.
A typical use of colcrt would be tbl exum2.n | nroff -ms | colcrt - | more
The colcrt command appeared in 3.0BSD.
Should fold underlines onto blanks even with the '-' option so that a true underline character would show. Cannot back up more than 102 lines. General overstriking is lost; as a special case '|' overstruck with '-' or underline becomes '+'. Lines are trimmed to 132 characters. Some provision should be made for processing superscripts and subscripts in documents which are already double-spaced. Characters that take up more than one column position may not be underlined correctly.
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.