Support direct exec with proper env set

[ahmubashshir]

diff --git a/archlinux-java-run.sh b/archlinux-java-run.sh
index 10c0f6f..22aab76 100755
--- a/archlinux-java-run.sh
+++ b/archlinux-java-run.sh
@@ -36,8 +36,8 @@ function print_usage {
 USAGE:
   archlinux-java-run [-a|--min MIN] [-b|--max MAX] [-p|--package PKG]
                      [-f|--feature FEATURE] [-h|--help] [-v|--verbose]
-                     [-d|--dry-run] [-j|--java-home]
-                     -- JAVA_ARGS
+                     [-d|--dry-run] [-j|--java-home] [-e|--exec]
+                     -- <JAVA_ARGS | EXEC_ARGS>
 
 EOF
 }
@@ -191,6 +191,23 @@ function generate_candiates {
   echo "$list" | xargs
 }
 
+function env_switch_java_home() {
+  quote_args
+
+  if [ $dryrun -eq 1 ]; then
+    echo "DRY-RUN - Generated command: env JAVA_HOME=/usr/lib/jvm/${ver} PATH=/usr/lib/jvm/${ver}/bin:\$PATH exec ${quoted_java_args[*]}"
+    exit 0
+  fi
+
+  if [ $verbose -eq 1 ]; then
+    echo_stderr "Executing command: JAVA_HOME=/usr/lib/jvm/${ver} PATH=/usr/lib/jvm/${ver}/bin:\$PATH exec ${quoted_java_args[*]}"
+  fi
+
+  export JAVA_HOME="/usr/lib/jvm/${ver}"
+  export PATH="/usr/lib/jvm/${ver}/bin:$PATH"
+  exec "${java_args[@]}"
+}
+
 function test_javafx_support() {
   if [ "$major" -lt 9 ]; then
     testcmd="/usr/lib/jvm/${ver}/bin/java -jar ${JAVADIR}/archlinux-java-run/TestJavaFX.jar"
@@ -243,6 +260,7 @@ for arg; do
     --min)       args+=( -a ) ;;
     --max)       args+=( -b ) ;;
     --help)      args+=( -h ) ;;
+    --exec)      args+=( -e ) ;;
     --package)   args+=( -p ) ;;
     --feature)   args+=( -f ) ;;
     --verbose)   args+=( -v ) ;;
@@ -256,6 +274,7 @@ features=( )
 java_args=( )
 quoted_java_args=( )
 verbose=0
+exec=0
 dryrun=0
 javahome=0
 args_parsed=0
@@ -307,6 +326,8 @@ while :; do
         ;;
     -j) javahome=1
         ;;
+    -e) exec=1
+        ;;
     --) args_parsed=1
         ;;
     '') break
@@ -353,6 +374,11 @@ for ver in $candidates; do
     exit 0
   fi
 
+  if [ $exec -eq 1 ]; then
+    env_switch_java_home
+    exit 0
+  fi
+
   for ft in "${features[@]}"; do
     case "$ft" in
     javafx)

[michaellass]

Hi! Is there a specific reason you posted this change as an issue instead of a pull request?

[ahmubashshir]

Didn't want to create yet another fork that I might delete after the PR gets merged...

It'd be great if github could create PR's from email (like source hut)

or, I can paste git-am'able patch if you want...

(actually I'm trying to convince myself that gerrit is a good idea, sent a few patches via gerrit so... /s)

[michaellass]

A patch file would be great. That way, there is a commit description and it states you as the author.

Some questions on the change itself:

• The default behavior of archlinux-java-run is to use exec to call Java. So it seems to me that the main addition of the newly added env_switch_java_home function is to set $JAVA_HOME and $PATH before doing the exec. Is that right? If so, exec seems not the most descriptive command line flag to trigger this behavior.
• Is it deliberate to call env_switch_java_home before the loop that adds feature-specific Java args?

[ahmubashshir]

As this executes arbitrary executable, instead of $JAVA_HOME/bin/java, I think it should be called before feature-specific java args...

I'll primarily use it to spawn a shell with non-default jdk to make gradle run without freaking out...

like this archlinux-java-run -b 11 -f jdk -e -- bash -i

[ahmubashshir]

or this flow will be better?

diff --git a/archlinux-java-run.sh b/archlinux-java-run.sh
index 10c0f6f..d3343b6 100755
--- a/archlinux-java-run.sh
+++ b/archlinux-java-run.sh
@@ -36,8 +36,8 @@ function print_usage {
 USAGE:
   archlinux-java-run [-a|--min MIN] [-b|--max MAX] [-p|--package PKG]
                      [-f|--feature FEATURE] [-h|--help] [-v|--verbose]
-                     [-d|--dry-run] [-j|--java-home]
-                     -- JAVA_ARGS
+                     [-d|--dry-run] [-j|--java-home] [-e|--exec]
+                     -- <JAVA_ARGS | EXEC_ARGS>
 
 EOF
 }
@@ -243,6 +243,7 @@ for arg; do
     --min)       args+=( -a ) ;;
     --max)       args+=( -b ) ;;
     --help)      args+=( -h ) ;;
+    --exec)      args+=( -e ) ;;
     --package)   args+=( -p ) ;;
     --feature)   args+=( -f ) ;;
     --verbose)   args+=( -v ) ;;
@@ -256,6 +257,7 @@ features=( )
 java_args=( )
 quoted_java_args=( )
 verbose=0
+exec=0
 dryrun=0
 javahome=0
 args_parsed=0
@@ -307,6 +309,8 @@ while :; do
         ;;
     -j) javahome=1
         ;;
+    -e) exec=1
+        ;;
     --) args_parsed=1
         ;;
     '') break
@@ -353,31 +357,36 @@ for ver in $candidates; do
     exit 0
   fi
 
-  for ft in "${features[@]}"; do
-    case "$ft" in
-    javafx)
-      if [ "$major" -gt 8 ]; then
-        echo_stderr "Modifying java arguments to support system installation of JavaFX"
-        additional_mpath=$(eval echo "/usr/lib/jvm/{${ver},java-${major}-openjfx}/lib/{javafx.base,javafx.controls,javafx.fxml,javafx.graphics,javafx.media,javafx.swing,javafx.web,javafx-swt}.jar" | tr ' ' :)
-        extend_java_args module-path "$additional_mpath" ':'
-        extend_java_args add-modules "$JAVAFX_MODULES" ','
-      fi
-      ;;
-    esac
-  done
+  if [ $exec -eq 0 ]; then
+    for ft in "${features[@]}"; do
+      case "$ft" in
+      javafx)
+        if [ "$major" -gt 8 ]; then
+          echo_stderr "Modifying java arguments to support system installation of JavaFX"
+          additional_mpath=$(eval echo "/usr/lib/jvm/{${ver},java-${major}-openjfx}/lib/{javafx.base,javafx.controls,javafx.fxml,javafx.graphics,javafx.media,javafx.swing,javafx.web,javafx-swt}.jar" | tr ' ' :)
+          extend_java_args module-path "$additional_mpath" ':'
+          extend_java_args add-modules "$JAVAFX_MODULES" ','
+        fi
+        ;;
+      esac
+    done
+    java_args=("/usr/lib/jvm/${ver}/bin/java" "${java_args[@]}")
+  else
+    java_args=("env" "JAVA_HOME=/usr/lib/jvm/${ver}" "PATH=/usr/lib/jvm/${ver}/bin:$PATH" "${java_args[@]}")
+  fi
 
   quote_args
 
   if [ $dryrun -eq 1 ]; then
-    echo "DRY-RUN - Generated command: /usr/lib/jvm/${ver}/bin/java ${quoted_java_args[*]}"
+    echo "DRY-RUN - Generated command: ${quoted_java_args[*]}"
     exit 0
   fi
 
   if [ $verbose -eq 1 ]; then
-    echo_stderr "Executing command: /usr/lib/jvm/${ver}/bin/java ${quoted_java_args[*]}"
+    echo_stderr "Executing command: ${quoted_java_args[*]}"
   fi
 
-  exec /usr/lib/jvm/"$ver"/bin/java "${java_args[@]}"
+  exec "${java_args[@]}"
 
 done

I tried minimizing line changes in the first patch...

[michaellass]

Ah, I missed that. OK, that is indeed a use case that I already needed in a package and implemented directly in the package. But having it in here does make sense.

Both versions are fine. I think I prefer the first one as it has less deep nesting. Could you post a git am patch?

[ahmubashshir]

0001-Add-exec-flag-to-run-commands-with-selected-JVM.patch

[michaellass]

Thanks for your contribution! I will likely release this as v12 soon (see #12)