Amiga Computing - Commodore Is Awesome

Neil Mohr explains
how to use
wildcards with
the Amiga's Shell
Continuing my little delve into the
Amiga Shell, I think it's about time
we had a talk about wildcards. Even
■^■M in their simplest form wildcards give
a way of dealing with a large a number of files,
in either manipulating selections of files or
using wildcards to ignore other selections.
A simple example would be to type into a
Shell: dir #?, in return you will get a straight
forward directory listing. Nothing stunning in
that, but you have just unwittingly used a wild
card, and probably one of the most commonly
used ones. What you have actually told the
Shell to do is give you a directory listing of
everything in the current directory. It just so
happens that typing dir will do the same thing,
but that's beside the point.
Wildcards allow you to tell the Shell to
match all the filenames in a directory against a
file pattern you have given it. This file pattern is
made up partly of wildcards and partly of a
normal filename. The simplest example
expanding on the first one would be dir l#?.
Here you have told the Shell to list every file
that starts with I.
The wildcard #? literally means anything
and where the Shell encounters it, it will match
anything to it. So if I were to ask you to find all
the words beginning with C and ending in G
you couid ask the computer the same with the
You have more than likely come across the situation where
you have typed a command or program name into the
Shel! and it has returned with unknown command, but you
know fulf well that it is on your hard drive. This happens
because the Amiga's operating system maintains a list of
directories which it will search for commands when using
either the Workbench or Shell.
The standard search path is set up in the startup
sequence and you can check what this is by typing PATH
into a Shell and it will display a list of ail the directories
that will be searched. If you want to add further directories
you can either add them to the list in the startup sequence
of you could add another path line in the user-startup, and
at the end of list of extra directories put the command
ADD. This tells the path command that you want to add
these extra directories to the current list and to replace it.
When using the she!! you can add extra directories at
any time and the current Shell will use the new path list
You should be aware only that Shell will use it and the
Workbench search path will also stay unaffected. If you
want to update the Workbench path list you need to type
LoadWB NEWPATH and the Workbench will inherit the
new path.
Amiga Computing
MARCH 1997
en inf.
tiiii'i info
Dist into
Lies info
HUI. info
£(or*9».Info
Tooli Info
wO*i»rlup.Inf
7 Workb«>ch 1
following C#?C.
Real wild
child
If I also wanted words that had an i in the
middle you could do this with C#?I#?G. To put
this in more computer oriented context; if you
want to specify just the icon files in a directory
then you would use #?.info to do so, or for
Jpegs you could use #?.jpg.
Things start to get a little more complex
when other wildcards are introduced. Two that
are of most use are the NOT and OR wildcards
represented by the - and | symbols. This helps
you lump together wildcard definitions. So if
you wanted to perform some operation on all
the GIF and Jpeg files this would do the trick:
(#?.gif|#?.jpg). The brackets tell the Shell what
the pattern is and the bar tells it that files
matching either wildcard will do. So any file
ending with .GIF or JPG will be used.
The little squiggle symbol, called a tilde, rep
resents a Boolean not, or tells the Shell to
ignore files that match following file pattern.
This is useful in ASL file requesters that allow
patterns entered to filter the file listing. To get it
to ignore all the icon files you can enter
-•(#?.info) and all the icon files will be
removed from the file list. This can be useful
when using a specific program - if you save all
your files off with the same file extension such
as .ww for Wordworth by using #?.ww in the
file pattern gadget only Wordworth files will
be shown.
You should be aware that the hash and
question mark wildcards are actually two sepa
rate wildcards that when used together just
happen to match any characters. The question
mark will match any single character in a
name. So A?C will match any occurrence of A
and C with any other character in-between
them.
The hash mark is slightly more complex as it
will match zero or more occurrences of a pat
tern. So A#BC will match A and along with any
number of B's in-between them. So AC, ABC
and ABBBC are ail valid matches. As you have
already seen brackets or parenthesise can be
used to enclose wildcard definitions and allow
you to show AmigaDOS exactly which set of
characters it should use, this becomes handy
when you need to show AmigaDOS that you
want to specify a group of characters to match
and not just a single one. So using A#(BC) you
can tell AmigaDOS that you want to match
every A that is followed by any number of BC's.
A final wildcard and one you probably will
not have to use very much in the null character
which Is represented with a percent sign and is
just a way of giving the computer a chance to
ignore a match. So A(B|°/a)C will match both
ABC and just AC as you have given the null
option.
CI0K1) 9*« full, 99B9K
731 rull. 31011
100* full, 0K
CK»ln> 42* full, 72M
The latest ASL requester gives you everything ReqTools does including the handy pattern
requester, wildcards crop up quite a lot when dealing with files