An Ingres Blog

I recently discovered ctags, a program that generates a tag/index file for C, Java, PHP, Python, Ruby. For those new to the Ingres source ctags is an invaluable tool for navigating the Ingres source tree. Editors like vi and Emacs can use the generated tag file to allow the coder to go directly to the source for any Ingres function.

Here is how to setup ctags with Vim:

1. Install ctags for your operating system
• Linux distributions normally have a ctags package available
• The source for ctags can be obtained from http://ctags.sourceforge.net/
• Windows users can get ctags from http://ctags.sourceforge.net/
2. Generate the tag file for the Ingres source:ctags -R -f ~/.vim/tags/ingres.ctags /home/grant/src/svn/ingres/main/
• ~/.vim/tags/ingres.ctags is the target tag file. Windows: Use $HOME in place of ~
• /home/grant/src/svn/ingres/main/ is the full path to the Ingres source tree. The path used needs to absolute and not relative since Vim will need to navigate from the current working directory to the file containing the function definition.
3. Copy the following code into your $HOME/.vimrc:
" Tag files
set tags+=$HOME/.vim/tags/ingres.ctags
" Ctrl+Right Arrow to goto source of function under the cursor
map <silent><C-Left> <C-T>
" Ctrl+Left Arrow to go back
map <silent><C-Right> <C-]>

4. Open any Ingres source file with Vim, say main/src/common/odbc/driver/connect.c
5. Search for IIapi_initialize, somewhere around line 2276 (at least on my system)
6. Place the cursor over the function IIapi_initialize and then press Control+Right Arrow/Cursor
7. Vim should have loaded main/src/common/aif/aip/apiinit.c and placed the cursor on the following line (309):
IIapi_initialize( IIAPI_INITPARM II_FAR *initParm )
8. To go back to the previous file press Control+Left Arrow/Cursor

There you have it a simple way of navigating the Ingres source from the relative comfort of Vim.

Since it is possible to have multiple copies of Ingres running on box I was wondering how people switch between them. When I worked in support we used to hand write the scripts used to set-up the Ingres environment. Nowadays, at least with the Linux RPM releases, that script is written for you and placed in a known location ~ingres. Both these things make writing a master script to interrogate your Ingres installations (or instances as some people refer to them as). Below is the script I use:

echo "Release Running Script II_SYSTEM"
echo "-------------------------------------------------------------------------------"
for i in `ls ~ingres/.ing*bash`;
do
II_SYSTEM=`grep "II_SYSTEM=" $i | sed 's/^.*=//'`
II_INSTALLATION=`II_SYSTEM=$II_SYSTEM $II_SYSTEM/ingres/bin/ingprenv| grep II_INSTALLATION | sed 's/^.*=//'`
STATUS=`ps -fe | grep ingres | grep ${II_INSTALLATION} | grep dbms | wc -l`
if [ $STATUS -ge 2 ]; then
RUNNING=`echo "Y"`
else
RUNNING=`echo "N"`
fi
alias load${II_INSTALLATION}=". ${i}"
VERSION=`cat $II_SYSTEM/ingres/version.rel`
echo $VERSION " " $RUNNING " " load${II_INSTALLATION} $II_SYSTEM
done
alias show_ingres=". ~/bin/ingres_installs"


What it does
For each of the ~ingres/.ing*bash file the script extracts the following information:

• II_SYSTEM from the bash script
• Using II_SYSTEM, fetches the installation code (II_INSTALLATION)
• Checks to see there are at least two dbms processes running and prints the status, one is the dmfrcp (recovery server) the other is the real database server
• Sets up an alias of loadXX where XX is the 2 letter installation code obtained earlier
• Prints out the information obtained; Ingres version, running state, alias needed to access the installation and the value of II_SYSTEM

That script is invoked from .bashrc when the terminal in interactive mode (for non-interactive terminals, e.g. scp, the ingres_installs script might cause problems):

case "$-" in
*i*)
# List ingres installations and setup load aliases
. ~/bin/ingres_installs
echo
~/bin/newsig
;;
*) ;;
esac


So when I login or fire up a new terminal window I get:

Release Running Script II_SYSTEM
-------------------------------------------------------------------------------
II 9.2.0 (int.lnx/114)NPTL Y loadII /opt/Ingres/IngresII
II 9.1.0 (int.lnx/123)NPTL N loadR2 /opt/Ingres/R2
II 9.2.0 (int.lnx/118)NPTL Y loadR3 /opt/Ingres/IngresR3
~ [] [5.2.4]
09:00:11 >


So back to my original question, how do you manage multiple installations?