WAITS: Files and directories

Files are named file.ext where file is 1-6 characters long and ext 0-3. The extension is used to identify the type of file, eg HELLO.SAI would be a source code file in SAIL, the lab's version of Algol. One exception is seen in some shared directories, where the file extension is the initials of the person maintaining the file.

Filenames are case insensitive, and each character is stored using 6 bits instead of the usual 7 bit Stanford ASCII. This means that the special characters in Stanford ASCII like ← or α cannot be used in file names.

PPN means project and programmer number. These are both 1-3 alphanumeric characters long, with the programmer number (eg REG) identifying the person and the project number (eg 1) indicating a particular set of work. Programmer numbers can also be shared areas, eg DOC.

This information is given when you log in (eg typing L 1, REG) and also represents an area of the disk, for which is written in square brackets, (eg [1, REG]). By convention, [1, xxx] is like the home directory of user xxx, but the number 1 itself has no special meaning. Users would generally have different project numbers for different tasks, eg REG has [CRF, REG] for working on the CREF program and [DOC, REG] for documentation tasks.

To change directories, eg from [1, REG] to [DOC, REG] you could log out and log back in again with K and then L DOC,REG. But an easier way is to use ALIAS. With one argument this will change your project number, so ALIAS DOC will put you in [DOC, REG], as seen in the screenshot above. When invoked with two comma-separated arguments it will change to that PPN, eg ALIAS 1,BGB. With no arguments it will return to the directory you logged in as.

Typing R ALIAS will show what your current alias is, and what you logged in as.

To create a new directory, you need to log in with that PPN, so to create [FOO, REG] log out with K then log in with L FOO,REG. It will ask you for confirmation and then create an empty directory which you can start adding files to.

When you log out, if your logged in directory has zero files, it will be deleted.

Alphanumeric PPNs are a change from TOPS-10, which only allowed octal numbers. Unlike TOPS-10, there is no concept of sub-directories on WAITS.

There are several commands to manipulate files which share a common code base.

In general the arguments for these commands takes the form destination ← source. On display terminals you can get the left arrow by pressing the left cursor key; on TTYs, you can use underscore instead.

So COPY bar ← foo would copy foo, creating bar, and RENAME bar ← foo would change the filename foo to be bar.

Each file argument can be fully specified as

dev:file.ext[prj,prg]

dev is by default DSK: and does not need to be specified unless you are working with magnetic tape devices. prj,prg by default is the PPN you are currently logged in or aliased to.

The * wildcard means match all for the field it is specified in, eg *.txt. There is no partial wildcarding like a*.txt.

Some examples:

    RENAME *.BAK ← *.TXT

renames all text files in your current PPN to have an extension BAK.

    COPY X ← A,B,C

concatenates a, b and c to form x

    DIR MYLIST ← *.TXT

lists all files in the current PPN matching *.TXT and writes output to the file MYLIST.

There's also a working copy of PIP, DEC's Peripheral Interchange Program, on disk which you can run with R PIP. See my article in the TOPS-10 series of posts for more details.

The root of all directories is [1,1], also called the Master File Directory. If you do a DIR on this you can see each sub-directory as a file containing the PPN and the extension UFD, for User File Directory.

. dir [1,1]
...
  1REG  UFD    388  26-JUL-74
...
DOCREG  UFD    116  01-JAN-64
...

Some notable areas on the file system. As well as browsing these in WAITS, you can also look at the saildart archive by prepending https://www.saildart.org/ and either the PPN in brackets or the programmer number on its own, eg https://www.saildart.org/[S,DOC] or https://www.saildart.org/DOC .

The file manipulation commands are documented in COPY.RPH[S,DOC] in WAITS, or at saildart.org here.

We'll look at file protection, and user setup, in the next post.

I welcome any questions or comments, and also especially any corrections if I have got something wrong. Please email me at rupert@timereshared.com and I will add it here and update the main text.