Dear All,
I just tried making a symlink to sage and it broke because it defaults
to using $0 to work out where SAGE_DIR is. I'd like to propose a
small change that allows symlinks to be used:
---------------------------
THE FILE: is the shell script called sage in the root of the install
tree and which starts:
#!/bin/sh
# Set SAGE_ROOT to the location of the sage install.
SAGE_ROOT="....."
CUR="`pwd`" # save the current directory, so can change back after
startup
if [ "$SAGE_ROOT" = "....." ]; then
SAGE_ROOT=`echo "$0" | sed -e 's/....$//g'`
-----------------------------
BEFORE: The line I'd like to change is:
SAGE_ROOT=`echo "$0" | sed -e 's/....$//g'`
----------------------------
AFTER:
SAGE_ROOT=`readlink -f "$0"` 2>/dev/null || \
SAGE_ROOT=`realpath "$0"` 2>/dev/null || \
SAGE_ROOT="$0"
SAGE_ROOT="${SAGE_ROOT%/*}/"
--------------------------
DISCUSSION:
readlink -f and realpath do the same thing - they get a clean path
free of relative components and symlinks.
The reason for trying both is that some systems have only the one or
the other. Trying raw $0 is there as a last resort just in case.
Don't want to break any existing installs!
The final line does -almost- the same as the sed. The sed removes
four characters (sage), the new code removes the file part of the
path. Debatable but it's a bit quicker than spawning a sed process
and allows for name changes. You never know.. it might become
fennel. All right, this part of the argument is pretty weak!
But the upside is that I can now make symlinks to sage and everything
works dandy, which it didn't before.
Have fun!
And sorry about not using [code] tags .. I couldn't find the button!
(wimp)
Regards, Max (new to this forum)
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