[rfc][icedtea-web] get the custom jre in shell-launchers too

[Adam Domurad]

On 02/22/2013 09:43 AM, Jiri Vanek wrote:
> And finally bash launchers can check for the custom jre value too....
>
>
> J.
>
> ps: part of.. you know...
> pps: does this really replace all the c code!??!?! /me started to like 
> bash

It would be nice if C++ had a regex library. (added in C++11, but I 
doubt we'll see icedtea-web move to C++11.)

Actually during my internship I started to quite like hacking stuff with 
bash. Great & modular 'standard library' :-)

> diff -r ad2e15f15a75 launcher/itweb-settings.in
> --- a/launcher/itweb-settings.in    Thu Feb 21 15:26:38 2013 -0500
> +++ b/launcher/itweb-settings.in    Fri Feb 22 15:41:10 2013 +0100
> @@ -7,6 +7,16 @@
>  BINARY_LOCATION=@ITWEB_SETTINGS_BIN_LOCATION@
>  PROGRAM_NAME=itweb-settings
>
> +a="^deployment.jre.dir *= *"

'a' could probably get a better name here, ie 'JRE_PROPERTY' or some-such.

> +CUSTOM_JRE=`grep "$a" ~/.icedtea/deployment.properties 2>/dev/null |  
> sed "s/$a//g"`
> +if [ "x$CUSTOM_JRE" = "x" ] ; then
> +  CUSTOM_JRE=`grep "$a" /etc/.java/.deploy/deployment.properties 
> 2>/dev/null |  sed "s/$a//g"`
> +fi;
> +if [ "x$CUSTOM_JRE" != "x" ] ; then
> +  JAVA=$CUSTOM_JRE/bin/java
> +  CP=$CUSTOM_JRE/lib/rt.jar

AFAIK this CP= is not needed in itweb-settings.in.

> +fi;
> +
>  ${JAVA} ${LAUNCHER_BOOTCLASSPATH} ${LAUNCHER_FLAGS} \
>    -Dicedtea-web.bin.name=${PROGRAM_NAME} \
>    -Dicedtea-web.bin.location=${BINARY_LOCATION} \
> diff -r ad2e15f15a75 launcher/javaws.in
> --- a/launcher/javaws.in    Thu Feb 21 15:26:38 2013 -0500
> +++ b/launcher/javaws.in    Fri Feb 22 15:41:10 2013 +0100
> @@ -9,6 +9,16 @@
>  PROGRAM_NAME=javaws
>  CP=@JRE@/lib/rt.jar
>
> +a="^deployment.jre.dir *= *"
> +CUSTOM_JRE=`grep "$a" ~/.icedtea/deployment.properties 2>/dev/null |  
> sed "s/$a//g"`
> +if [ "x$CUSTOM_JRE" = "x" ] ; then
> +  CUSTOM_JRE=`grep "$a" /etc/.java/.deploy/deployment.properties 
> 2>/dev/null |  sed "s/$a//g"`
> +fi;
> +if [ "x$CUSTOM_JRE" != "x" ] ; then

This is funny. Are you trying to test for a non-empty string ?
[ "$CUSTOM_JRE" != "" ] works fine. ( [ $CUSTOM_JRE != "x" ] is the one 
that does not )
Since we have a default, it may also be worth checking [ -e 
"$CUSTOM_JRE" ] (file exists) here (and above).

> +  JAVA=$CUSTOM_JRE/bin/java
> +  CP=$CUSTOM_JRE/lib/rt.jar
> +fi;
> +
>  JAVA_ARGS=( )
>  ARGS=( )
>  COMMAND=()

Overall this is quite OK, if we do end up including the JRE path in the 
deployment properties file. Maybe though it will make life simpler if 
it's in its own file, eg '.icedtea/jre-path'?

You have a very valid point about the fact that we should avoid spawning 
a Java instance just to get the JVM arguments, however.
We might still want to parse the properties file for this, or we could 
place it in the file with the JRE path.
Considering that we need to extract this property from bash, C & Java, 
it might make sense to use the simplest format possible though. It would 
be very bad if a small mistake in how the property file is treated in 
Bash or C causes ITW not to be able to run.

Anyway properties file is not an overly scary format, but still worth 
thinking about.

Happy hacking,
-Adam