NAME

cr3 − controlled output flow filter for crt previewing

SYNOPSIS

cr3 [ name ...  ]

DESCRIPTION

Cr3 is a filter which allows causual examination of a continuous text on a soft-copy terminal.  It normally pauses after each 23 lines of output.  If the user then hits a carriage-return, 23 more lines are displayed.  If the user hits control-d, 11 more lines are displayed (a ‘scroll’). 

It is also possible to type positive numbers to cr3 causing that many lines to be printed, or negative numbers causing that many lines to be discarded followed by a scroll. 

The terminal is set to noecho mode by this program so that the output can be continuous.  The numbers and carriage returns you type will thus not show on your terminal. 

A sample usage of cr3 in previewing nroff output would be

nroff −ms +2 doc.n | cr3

AUTHOR

William Joy

ETYMOLOGY

Cr3 has its unusual name because Charles Haley implemented such a feature, which was enabled by

stty cr3

BUGS

The function of cr3 should be done optionally by the teletype driver in the system, akin to the “more” feature of the ITS systems at MIT.  It should be possible to scan forward throwing away or keeping output ala ‘/pattern’. 

7th Edition  —  2/24/79