mysql query and return value reaction

Dear Friends:

I started creating a plug-in to my application. It should install a webapplication into the local webspace. Like most webapplications this is based on PHP and MySQL.

The webapplication should use its own database user, so I need to get the credentials for the root user (user with global rights on the database) and use this informations to create the new database and a new user with password.

To solve this problem, I created a CustomPage where all these values must be filled by the user. I get all values back and pipe them into the following lines:

  nsExec::Exec '$INSTDIR\DB\MySQL4\bin\mysql -u $R0 -proot -e "CREATE DATABASE $R2"' 

with $R0 = root username
and $R2 = name of the database

As you can see in this line, -proot symbolises the parameter -p (switch for password entry) and a symbolic password root. And her I have my first problem:

If a user has no password set for his root user, neither the password nor the switch -p must be set. The CustomPage (custom.ini) is already prepared to serve a variable $R1 which could be placed as -p$R1, but mysql would react with an error if you trigger it with -p and provide no password. So I think the -p must be copied into $R0. How can I achieve this?

And another question. If the user enters a wrong password mysql will return an error. Can this error be used (or captured) to return e.g. a MessageBox and switch back to the CustomPage again...?

I hope somebody has a solution for me.

Chris

Ok meantime I solved problem one, to differ between an existing and a non-existent password with the following code:

  ;  -----  ask for MySQL root credentials
  ;         field 2=root user
  ReadINIStr $R0 "$PLUGINSDIR\\mysql.ini" "Field 2" "State"
  ;         field 3=password for root user
  ReadINIStr $R1 "$PLUGINSDIR\\mysql.ini" "Field 3" "State"
  ;  -----  ask for creating a new MySQL User
  ;         field 11=database
  ReadINIStr $R2 "$PLUGINSDIR\\mysql.ini" "Field 11" "State"
  ;  -----  field 12=new database user
  ReadINIStr $R3 "$PLUGINSDIR\\mysql.ini" "Field 12" "State"
  ;  -----  field 13=password for new database user
  ReadINIStr $R4 "$PLUGINSDIR\\mysql.ini" "Field 13" "State" 
  ;  -----  use the informations above to create the database 
  StrCmp $R1 "" EmptyPwd notEmptyPwd
  EmptyPwd:
  
  ;  -----  if no password is given
  ;
  nsExec::ExecToLog '$INSTDIR\\DB\\MySQL4\\bin\\mysql -u $R0 -e "CREATE DATABASE $R2"'
  nsExec::ExecToLog '$INSTDIR\\DB\\MySQL4\\bin\\mysql -u $R0 -e "GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, INDEX, ALTER, CREATE TEMPORARY TABLES ON $R2.* TO $\\'$R3$\\'@$\\'localhost$\\' IDENTIFIED BY $\\'$R4$\\'"'
  
  goto PwdDone
  notEmptyPwd:
  ;  -----  if the passwd field is filled...
  ;
  nsExec::ExecToLog '$INSTDIR\\DB\\MySQL4\\bin\\mysql -u $R0 -p$R1 -e "CREATE DATABASE $R2"'
  nsExec::ExecToLog '$INSTDIR\\DB\\MySQL4\\bin\\mysql -u $R0 -p$R1 -e "GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, INDEX, ALTER, CREATE TEMPORARY TABLES ON $R2.* TO $\\'$R3$\\'@$\\'localhost$\\' IDENTIFIED BY $\\'$R4$\\'"'
  
  PwdDone: 

But there is still the problem, that the installer will finish even if the mysql database returns an error.

Any idea to solve this?
Chris

What about mysql stdout parsing?
nsExec:
if (log & 2) pushstring(szUnusedBuf);
if (log & 1 && *szUnusedBuf) LogMessage(szUnusedBuf);
pushstring(szRet);

And BTW it is possible to prepare and use stdin string for DOS processes http://forums.winamp.com/showthread....ght=dos+plugin

Thx for your reply Takhir -

How do I use this? After the part I posted, there has to be this "see what mysql gives back" part. but I am a non-programmer living from snippets and manuals to achieve my goals ;-)

Thx
Chris