Software Installation on the Mac
alanj
and Linux user. I just bought a Mac and want to learn how to do things
correctly with it. Many things are not obvious, the first being
software installation. I have searched the usenet groups and read many
posts, but several things still do not make sense to me. I'm hoping
someone can enlighten me.
Let me use a concrete example: installing Firefox.
I went to www.getfirefox.com and clicked the download button. It was
very nice that the web site knew I needed the Mac version and
automatically sent it to me (this after years of having to choose the
correct Windoze version for all downloads, or the correct tar.gz file
for my linux distro).
When the download completed, things started happening without any
action on my part, and the next thing I knew there was an icon on my
desktop. (Some searching around in Safari showed me that my downloaded
files were being launched automatically, which I turned off.) Turns out
the downloaded file was a DMG file. Some more reading on the web taught
me the DMG file was basically an archive containing all the app's
files.
The problem is I don't WANT the dmg stored permantly on my desktop.
Somewhere in a usenet post I read that people usually copy the dmg file
to their Application folder. I tried to do this, but the system won't
let me. It just creates an alias (shortcut? symlink?) in the
Application folder and leaves the dmg file on the desktop. I DON'T WANT
IT THERE.
The second weird thing is that double-clicking the dmg file to launch
the application only opens a 'intermediate' window (don't know what
else to call it) with another Firefox icon in it. I have to
double-click that second icon to get Firefox to start for real. Why is
that? Why can't I just double-click the icon on the desktop and get
Firefox to launch directly?
Thirdly, when the dmg file is opened (or launched or run, or whatever
the correct term is) and the app is presumably installed, are the
contents of the dmg copied somewhere, or are they just left in the dmg
file (like java files might be left in a jar file)? Somewhere I read
that you can delete the dmg file after installing, but that does not
appear to be the case with Firefox. I deleted the dmg file on my
desktop (because I don't want it there) and that apparently uninstalled
the application. In a way this was good, because it gave me a chance to
get more practice by installing again. But when I tried again, there
didn't seem to be any way to avoid the snafus mentioned above. The app
just installed itself again, with the same result: a dmg file left
cluttering the desktop, and a two-step launching process.
To make a longer story shorter, I basically have no idea what is
happening when you install Firefox (or any other app) on a Mac G5. I
also cannot find an explanation anywhere on the web.
Can someone point me to a howto or tutorial or something, or give me a
few pointers here? I'm willing to put in the time to learn the Mac
paradigm (just like I put in the time to learn Windoze and Linux), but
I must say that the sysadmin basics so are far from obvious.
Thanks very much,
Alan
David Empson
> I'm a new Mac owner. Please don't flame me because I'm also a Wintel
> and Linux user. I just bought a Mac and want to learn how to do things
> correctly with it. Many things are not obvious, the first being
> software installation. I have searched the usenet groups and read many
> posts, but several things still do not make sense to me. I'm hoping
> someone can enlighten me.
Sure thing.
> Let me use a concrete example: installing Firefox.
>
> I went to www.getfirefox.com and clicked the download button. It was
> very nice that the web site knew I needed the Mac version and
> automatically sent it to me (this after years of having to choose the
> correct Windoze version for all downloads, or the correct tar.gz file
> for my linux distro).
>
> When the download completed, things started happening without any
> action on my part, and the next thing I knew there was an icon on my
> desktop. (Some searching around in Safari showed me that my downloaded
> files were being launched automatically, which I turned off.) Turns out
> the downloaded file was a DMG file. Some more reading on the web taught
> me the DMG file was basically an archive containing all the app's
> files.
DMG is short for "Disk Image". It is the native Mac OS X format for
creating images of actual disks (e.g. CDs or an entire hard drive
partition) or a folder. The format has a variety of options, including
fixed or dynamically sized volumes, read/write, read only or compressed,
and encryption.
It is commonly used as a distribution method for software installers.
When you open a .dmg file by double-clicking it, the system behaves like
it would if you inserted a disk into a drive in the computer: it mounts
the disk on the desktop, with an icon which resembles a white floppy
disk drive (which may be customized in some cases: Firefox has part of
its icon on top of the "floppy drive").
That icon can then be double-clicked to examine the contents of the disk
image (and modified, if the image is read/write).
When you have finished using the mounted disk image, you eject it in the
same manner as any other mounted volume, by dragging the "floppy drive"
icon to the trash (which will change to an eject symbol to show that you
are ejecting something, not deleting it).
The .dmg file cannot be deleted until you have ejected the image, but
you can move the .dmg file somewhere else. I typically file mine in a
"To Archive" folder and occasionally get around to burning them all onto
a CD to free up some disk space.
> The problem is I don't WANT the dmg stored permantly on my desktop.
> Somewhere in a usenet post I read that people usually copy the dmg file
> to their Application folder.
That is a strange suggestion. The .dmg file isn't an application, so why
put it in the Applications folder? As noted above, I keep them in a "To
Archive" folder, or perhaps an "Archived" or "Installers" folder if I
want to hang onto them after I've burned them to CD. If I don't want to
keep a .dmg file, I delete if after using/installing its contents.
> I tried to do this, but the system won't let me. It just creates an alias
> (shortcut? symlink?) in the Application folder and leaves the dmg file on
> the desktop. I DON'T WANT IT THERE.
Are you sure you dragged the .dmg file? I think you actually dragged the
mounted disk image (icon which looks like a floppy drive).
You should be able to drag the .dmg file itself into any folder in which
you have write privileges. If you are a non-admin user, you can't modify
the contents of the Applications folder, but that would also mean you
can't create an alias in it.
If you drag an icon for a volume (mounted disk image, CD, hard drive,
etc.) onto another volume (or into a window showing the contents of a
folder on another volume), the normal behaviour of Finder is to create
an alias rather than copying it. If you actually want to copy the entire
volume (which you probably shouldn't do in this case), you can do so by
holding down the Option key while dragging the icon.
> The second weird thing is that double-clicking the dmg file to launch
> the application only opens a 'intermediate' window (don't know what
> else to call it) with another Firefox icon in it.
You've actually double-clicked the mounted disk image, which has opened
a window showing its contents. Think of it like a CD you have inserted
into the computer. If you double-click on a CD icon, you will see a
window showing what is on the CD.
If you double-clicked the .dmg file, it would attempt to mount the
volume again, but wouldn't bother because it is already mounted.
> I have to double-click that second icon to get Firefox to start for real.
> Why is that?
Firefox is distributed as an application (Firefox.app) within the disk
image. If you want to run Firefox directly from the disk image without
actually installing it on the hard drive, you can double-click it to
launch it. (The same principle would apply if you were running an
application from a CD.)
Assuming you want to use Firefox regularly, you shouldn't double-click
it in the disk image window, but instead open another Finder window and
drag Firefox.app into your Applications folder. (Some disk images
actually contain a soft link to your Applicatons folder, making it easy
to drag the application there without opening another window. Firefox
just has a picture on the window background showing how to do it.)
After you have dragged Firefox.app to your Applications folder, you can
eject the disk image (drag the "Firefox" floppy drive icon to the
trash). If you had launched Firefox.app from the disk image, you will
have to Quit it first, because the disk image will still be in use as
long as that copy of the application is running.
After you have ejected the disk image, you can delete the Firefox
1.5.0.1.dmg file (or move it somewhere for safe keeping, in case you
need to install it again later).
> Why can't I just double-click the icon on the desktop and get
> Firefox to launch directly?
Because double-clicking that icon is opening a mounted volume, not
launching an application.
> Thirdly, when the dmg file is opened (or launched or run, or whatever
> the correct term is)
Take your pick. A .dmg file is a document, so "opened" would be the
correct term. A .app file is an application, so "launched" or "run"
would be the correct term.
> and the app is presumably installed, are the contents of the dmg copied
> somewhere, or are they just left in the dmg file (like java files might be
> left in a jar file)?
If you ran Firefox.app directly from the disk image, then it won't be
copied anywhere automatically. You have to copy it to your Applications
folder if you want to keep it.
> Somewhere I read that you can delete the dmg file after installing, but
> that does not appear to be the case with Firefox. I deleted the dmg file
> on my desktop (because I don't want it there) and that apparently
> uninstalled the application.
In a way, yes, because the only copy of the application was buried
inside the disk image. If you had dragged Firefox.app out of the disk
image and put it in your Applications folder, then you could delete the
disk image and would still have a copy of Firefox in the Applications
folder.
> In a way this was good, because it gave me a chance to get more practice
> by installing again. But when I tried again, there didn't seem to be any
> way to avoid the snafus mentioned above. The app just installed itself
> again, with the same result: a dmg file left cluttering the desktop, and a
> two-step launching process.
>
> To make a longer story shorter, I basically have no idea what is
> happening when you install Firefox (or any other app) on a Mac G5. I
> also cannot find an explanation anywhere on the web.
I agree - some applications don't make it very clear. Others are much
better: they might have a Read Me file which explains what to do, or
detailed instructions on the background of the disk image window.
It is also worth mentioning another type of file you are likely to find
on some downloaded disk images (particularly from Apple): a "package"
(extension ".pkg", icon looks like an opened cardboard box with an
orange tint). With this type of file, you don't drag it out of the disk
image, you should double-click it. This runs the Mac OS X Installer
which will run through several steps, prompting you as required: show
licence agreements, let you pick a target volume, choose any relevant
options, install the files in the right places, and restart the computer
if necessary.
--
David Empson
dem...@actrix.gen.nz
Gregory Weston
"alanj" <adj...@gmail.com> wrote:
> I'm a new Mac owner. Please don't flame me because I'm also a Wintel
> and Linux user.
Noone will. The tendency of Mac users to randomly flame people who are
not, or were not until recently, Mac users is overstated and mostly
imagined.
> I just bought a Mac and want to learn how to do things
> correctly with it. Many things are not obvious, the first being
> software installation.
Software installation on the Mac, for the most part, is: Drag this
application (or the folder containing it and some ancillary files) onto
your hard drive. If you want. In many (although not all) cases you can
run from the distribution media directly.
Some software comes with an installer.
A very small number of programs have more complicated manual installs
(including just the notion that this particular program can't run from
the distribution media) and would typically come with a document
explaining what the user needs to do to get a working installation.
> Let me use a concrete example: installing Firefox.
You would have to pick that. ;) That'd be in that last group. FireFox
must do its first run from a writable location because it modifies
itself. Poor practice and quite rare, but there it is.
> The problem is I don't WANT the dmg stored permantly on my desktop.
> Somewhere in a usenet post I read that people usually copy the dmg file
> to their Application folder.
Nope. Generally people would copy (some subset of) the contents of the
disk image to /Applications. The Disk Image itself would then be
unmounted and then the DMG file either thrown away or put in some
archival location.
And there's probably a source of your confusion. You likely have _two_
icons on your desktop related to that download. You've got the DMG file
you actually downloaded, plus - because Safari auto-opened it - you've
got a virtual disk mounted, showing up like any CD or USB flash drive
might.
> I deleted the dmg file on my
> desktop (because I don't want it there) and that apparently uninstalled
> the application. In a way this was good, because it gave me a chance to
> get more practice by installing again. But when I tried again, there
> didn't seem to be any way to avoid the snafus mentioned above. The app
> just installed itself again, with the same result: a dmg file left
> cluttering the desktop, and a two-step launching process.
And that's because what you're doing is not installing and uninstalling
and app, but mounting and unmounting a "disk."
G
--
"Congurutulation!!!" - The subject line on some spam I received recently.
I have no idea what it means, but it's such a cool "word" (by which I mean
pronouncable sequence of letters) regardless.
alanj
Wow. What great explanations and information. Everything is crystal
clear to me now. Thank you so much. The key parts that caused me so
much confusion were
- when a dmg is opened, it actually acts like a mounted filesystem, and
you access the mounted volume through the icon on the desktop. (By the
way Greg: I did not have two icons on the desktop, only because I had
told Safari to save downloaded files in Documents/Downloads. So the
actual dmg was in my Downloads folder [duh]. If the dmg had been saved
on the Desktop, I may have actually figured more of this out on my
own.)
- When Safari automatically opened the dmg file, I was faked into
believing that the app was being "installed" because, when the dmg
opened (was mounting), it presented a licensing dialog with an "Agree"
button. I hit Agree, then the Firefox icon appeared on the desktop. To
my Windows-centric brain, it appeared that some installation process
had copied the app file to its home somewhere, and that a link to the
app file had been created on the desktop. Now I know what really
happened. (Basically nothing happened, except the dmg was mounted!)
- The third confusion was that, when the mounted dmg opened, instead of
showing me a list of files (which would have been a clue to me that I
was looking at the contents of a file system) it showed me three fancy
icons: 1) a Firefox icon, 2) an arrow pointing to 3) a folder with a
capital "A" on it. As stupid as it makes me sound, I had no clue
whatsoever that that meant 'drag this icon (the app file) to the
Applications folder.'
Hopefully this post and your great explanations will help someone else.
Thanks again.
David: my daughter is in NZ right now, spending a year working and
traveling before going on to university in the fall. She is a waitress
at a ski lodge on the South Island. My wife is visiting her there right
now and says it is breathtakingly beautiful. I'm stuck here at home
playing with a new Mac :)
Regards,
Alan