Add exec flag to run commands with selected JVM

CHANGES.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## v12
+2026-02-20
+
+* Support running arbitrary programs with $JAVA_HOME and $PATH set according
+  to requested Java version (#11, #12)
+
 ## v11
 2025-01-03
 

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2017, 2018, 2019, 2020, 2023, 2024 Michael Lass
+Copyright (c) 2017–2026 Michael Lass
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -12,14 +12,16 @@ this version, the one corresponding to the user's default JVM is used.
 By default, archlinux-java-run will execute a suitable version of java
 with the given JAVA_ARGS. When run with -j|--java-home, it just prints
 the location of a suitable java installation so that custom commands
-can be run.
+can be run. When run with -e|--exec, it will run EXEC_CMD in an
+environment where $JAVA_HOME and $PATH is set so that the appropriate
+Java version is used.
 
 ## 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_CMD>
 ```
 
 ## Available features
@@ -45,3 +47,6 @@ can be run.
 
 * Launch javac from a JDK in version 11 or newer:
   `JAVA_HOME=$(archlinux-java-run --min 11 --feature jdk --java-home) && "$JAVA_HOME"/bin/javac ...`
+
+* Launch interactive bash with Java 25 set as $JAVA_HOME and as first element in $PATH:
+  `archlinux-java-run --min 25 --max 25 --exec -- bash -i`

archlinux-java-run.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 #
-# (c) 2017, 2018, 2019, 2020, 2023, 2024 Michael Lass
+# Copyright (c) 2017–2026 Michael Lass
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -25,7 +25,7 @@
 # This script uses `exec` on purpose to launch a suitable JRE before the end of
 # the script.
 # shellcheck disable=SC2093
-VERSION=11
+VERSION=12
 JAVADIR=###JAVADIR###
 
 JAVAFX_MODULES=javafx.base,javafx.controls,javafx.fxml,javafx.graphics,javafx.media,javafx.swing,javafx.web
@@ -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_CMD>
 
 EOF
 }
@@ -58,7 +58,9 @@ this version, the one corresponding to the user's default JVM is used.
 By default, archlinux-java-run will execute a suitable version of java
 with the given JAVA_ARGS. When run with -j|--java-home, it just prints
 the location of a suitable java installation so that custom commands
-can be run.
+can be run. When run with -e|--exec, it will run EXEC_CMD in an
+environment where \$JAVA_HOME and \$PATH is set so that the appropriate
+Java version is used.
 EOF
   print_usage
   cat << EOF
@@ -86,6 +88,8 @@ EXAMPLES:
       && "\$JAVA_HOME"/bin/javac ...
     (launches javac from a JDK in version 11 or newer)
 
+  archlinux-java-run --min 25 --max 25 --exec -- bash -i
+    (launches interactive bash with Java 25 set as \$JAVA_HOME and as first element in \$PATH)
 EOF
 }
 
@@ -191,6 +195,23 @@ function generate_candiates {
   echo "$list" | xargs
 }
 
+function exec_in_modified_env() {
+  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 +264,7 @@ 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 +278,7 @@ features=( )
 java_args=( )
 quoted_java_args=( )
 verbose=0
+exec=0
 dryrun=0
 javahome=0
 args_parsed=0
@@ -307,6 +330,8 @@ while :; do
         ;;
     -j) javahome=1
         ;;
+    -e) exec=1
+        ;;
     --) args_parsed=1
         ;;
     '') break
@@ -353,6 +378,10 @@ for ver in $candidates; do
     exit 0
   fi
 
+  if [ $exec -eq 1 ]; then
+    exec_in_modified_env
+  fi
+
   for ft in "${features[@]}"; do
     case "$ft" in
     javafx)