Singular

Conflicting HOME variables under Windows
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The system variable HOME is used by Singular and other programs. The
modifications of this variable during the installation procedure may
lead to conflicts.
A) Where is the variable HOME defined?
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a) Windows 9x/ME
HOME is defined by a line "SET HOME = ..." in the file "autoexec.bat".
b) Windows NT/2000
Under "Environment" in the "Control Panel" there could be two
definitions of
HOME, namely as a system variable (in the upper subwindow) and as a user
variable (in the lower subwindow). By default, the variable HOME
appears only as a system variable or doesn"t appear at all.
B) How is the variable HOME modified by the Singular installation?
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a) Windows 9x/ME
A new line "SET HOME = ..." defining the Singular home directory is
inserted in the file "autoexec.bat" after the existing line "SET HOME =
...." defining the user home directory.
To prevent the system from destroying the old settings, replace the line
"SET HOME = ..." defining the user home directory by the line
"REM SET HOME = ..." or copy it to another place.
b) Windows NT/2000
If the value of the variable HOME is correct (i.e. the given directory
exists), the installation proceed as follows.
First, a copy of the old variable HOME is moved to the new variable
OLDHOME. Afterwards, the variable HOME is set to the Singular home
directory.
If either the variable HOME is not defined or
it contains a non-existing path, then
the variable HOME is set to the Singular home directory.
C) Where is the value of the variable HOME relevant?
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a) Some versions of (X)Emacs for Windows and other programs
(like Star Office) need this variable to find their home directory.
So need it the XEmacs version 21.1.12, which is included in the
Singular distribution.
In order to use different versions of (X)Emacs, one has to run (X)Emacs
and ESingular (which works as an application within the XEmacs 21.1.12,
shipped with the distribution) separately and eventually use some tricks
(like batch files or registry macros) for changing the value
of the variable HOME appropriately.
b) Shortcuts like Singular, TSingular, ESingular, Bash Shell, or Xemacs
will be run from the directory defined by the variable HOME.
In order to run Singular, TSingular, and ESingular from the
directory, which is different from the one defined in HOME,
you can proceed as follows:
1) Define a new variable (SINGHOME, for example) containing the path of the
directory you wish to use.
2) Right click on one of the shortcuts Singular, TSingular, or ESingular
and choose "Shortcut tab".
3) Enter %SINGHOME% in the field "Start in". By default,
this field contains the string %HOME%.
Note that there are two types of independent shortcuts, namely on the
desktop and in the "Start" menu.
d) Troubleshooting and additional information
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The following variables could be set additionally
for various troubleshooting operations :
ESINGULAR_EMACS = the full path to "emacs.exe" or "xemacs.exe"
ESINGULAR_SINGULAR = the full path to your file "Singular.exe"
ESINGULAR_EMACS_LOAD = the full path to your file ".emacs-singular"
ESINGULAR_EMACS_DIR = the full path to your directory /Singular/2-0-0/emacs
If some of these variables are present in the system,
Singular will use them internally for calling the respective data.
Viktor Levandovskyy (Singular Team, Windows Group)

email: levandov@mathematik.uni-kl.de
Posted in old Singular Forum on: 2001-08-08 16:04:17+02