UNIX Operating System

Various UNIX systems are available from IBM itself, Microsoft-SCO, Bell, Berkley, and various UNIX clones such as MINIX (a multitasking UNIX clone). The different varieties of this venerable OS include single and multi user systems.

Common commands:

cp filename1 filename2 --- copies a file

cd directory Change Directory

diff filename1 filename2 --- compares files, and gives instructions to make filename1 into filename2 in the format: #L# or #,#L#,# where # is the line in the first file, L is a letter for the operation (a)dd, (c)change, (d)elete. then the # after the letter is the line number(s) from the second file. E.g. 2,4c2,4 means that lines 2 thru 4 in the first file should be changed to lines 2 thru 4 in the second file. It will follow those instructions with a copy of the lines, whith < before the lines from the first file and > before the lines from the second file.

diff -c filename1 filename2 --- All lines are shown, lines that need to be added to the first file have a + in front, lines that need to be deleted have a -, and a ! in front of lines that have changes inside them.

ff --- find files anywhere on the system. This can be extremely useful if you've forgotten in which directory you put a file, but do remember the name. In fact, if you use ff -p you don't even need the full name, just the beginning. This can also be useful for finding other things on the system, e.g. documentation.

grep string filename(s) --- looks for the string in the files. This can be useful a lot of purposes, e.g. finding the right file among many, figuring out which is the right version of something, and even doing serious corpus work. grep comes in several varieties (grep, egrep, and fgrep) and has a lot of very flexible options. Check out the man pages if this sounds good to you.

ls --- lists your files
ls -l --- lists your files in 'long format', which contains lots of useful information, e.g. the exact size of the file, who owns the file and who has the right to look at it, and when it was last modified.
ls -a --- lists all files, including the ones whose filenames begin in a dot, which you do not always want to see.

mkdir directory Make a new Directory

rm filename --- removes a file. It is wise to use the option rm -i, which will ask you for confirmation before actually deleting anything. You can make this your default by making an alias in your .cshrc file.

When trying to load binary images through a parallel port, as with the simple DOS command:>

COPY <filename> LPT1 /B

You might have the best luck with the following UNIX command:

 dd if=<sourcefile> of=/dev/lp1

'dd' is a handy utility to perform raw transfers without adding any extraneous characters.

Linux@

GNU'S NOT UNIX Conducted by David Betz and Jon Edwards Richard Stallman discusses his public-domain UNIX-compatible software system with BYTE editors (July 1986)