Linux Commands: Display output one screen at a time
- Display output one screen at a time
Syntax: more [-dlfpcsu] [-num] [+/ pattern] [+ linenum] [file ...]
Description: There is a more command that comes with util-linux, but it will not work for this project. The reason is because of library dependencies and space constraints. The util-linux supplied more needs either the libncurses or libtermcap to work and there just is not enough space on the root disk floppy to fit everything in. So, in order to have a more command we will have to get creative.
The more command is used to display a file page by page. It's a little like having a cat command that pauses every twenty-five lines. The basic logic is outlined below.
- Read one line of the file.
- Display the line on the screen.
- If 25 lines have been displayed, pause.
- Loop and do it again.
Of course there are some details left out like what to do if the screen dimensions are not what we anticipated, but overall it is a fair representation of what more does. Given this simple program logic, it should not be hard to put together a short shell script that emulates the basic functionality of more. The BASH(1) manpage and Adv-BASH-Scripting-Guide will serve as references.
Related: echo, less, tee
Other Linux Commands: