[CORDA-2211]: Added error for older bash versions when attempting to install shell extensions. (#4263)

build.gradle

@@ -71,6 +71,7 @@ buildscript {
     ext.class_graph_version = '4.2.12'
     ext.jcabi_manifests_version = '1.1'
     ext.picocli_version = '3.8.0'
+    ext.commons_io_version = '2.6'
 
     // Name of the IntelliJ SDK created for the deterministic Java rt.jar.
     // ext.deterministic_idea_sdk = '1.8 (Deterministic)'

tools/cliutils/build.gradle

@@ -9,6 +9,7 @@ dependencies {
     compile project(":core")
     
     compile "info.picocli:picocli:$picocli_version"
+    compile "commons-io:commons-io:$commons_io_version"
     compile "com.jcabi:jcabi-manifests:$jcabi_manifests_version"
     compile "org.slf4j:slf4j-api:$slf4j_version"
     compile "org.apache.logging.log4j:log4j-slf4j-impl:$log4j_version"

tools/cliutils/src/main/kotlin/net/corda/cliutils/CordaCliWrapper.kt

@@ -184,6 +184,10 @@ abstract class CordaCliWrapper(alias: String, description: String) : CliWrapperB
     }
 
     fun printHelp() = cmd.usage(System.out)
+
+    fun printlnErr(message: String) = System.err.println(message)
+
+    fun printlnWarn(message: String) = System.err.println(message)
 }
 
 /**

tools/cliutils/src/main/kotlin/net/corda/cliutils/InstallShellExtensionsParser.kt

@@ -1,6 +1,8 @@
 package net.corda.cliutils
 
 import net.corda.core.internal.*
+import org.apache.commons.io.IOUtils
+import org.apache.commons.lang.SystemUtils
 import picocli.CommandLine
 import picocli.CommandLine.Command
 import java.nio.file.Path
@@ -9,6 +11,10 @@ import java.nio.file.StandardCopyOption
 import java.util.*
 
 private class ShellExtensionsGenerator(val parent: CordaCliWrapper) {
+    private companion object {
+        private const val minSupportedBashVersion = 4
+    }
+
     private class SettingsFile(val filePath: Path) {
         private val lines: MutableList<String> by lazy { getFileLines() }
         var fileModified: Boolean = false
@@ -80,10 +86,22 @@ private class ShellExtensionsGenerator(val parent: CordaCliWrapper) {
         autoCompleteFile.writeText(builder.toString())
     }
 
-    fun installShellExtensions() {
+    fun installShellExtensions(): Int {
         // Get jar location and generate alias command
         val command = "alias ${parent.alias}='java -jar \"${jarLocation.toStringWithDeWindowsfication()}\"'"
+        var generateAutoCompleteFile = true
+        if (SystemUtils.IS_OS_UNIX && installedShell() == ShellType.BASH) {
+            val semanticParts = declaredBashVersion().split(".")
+            semanticParts.firstOrNull()?.toIntOrNull()?.let { major ->
+                if (major < minSupportedBashVersion) {
+                    parent.printlnWarn("Cannot install shell extension for bash major version earlier than $minSupportedBashVersion. Please upgrade your bash version. Aliases should still work.")
+                    generateAutoCompleteFile = false
+                }
+            }
+        }
+        if (generateAutoCompleteFile) {
             generateAutoCompleteFile(parent.alias)
+        }
 
         // Get bash settings file
         val bashSettingsFile = SettingsFile(userHome / ".bashrc")
@@ -101,9 +119,34 @@ private class ShellExtensionsGenerator(val parent: CordaCliWrapper) {
         zshSettingsFile.addIfNotExists(completionFileCommand)
         zshSettingsFile.updateAndBackupIfNecessary()
 
+        if (generateAutoCompleteFile) {
             println("Installation complete, ${parent.alias} is available in bash with autocompletion.")
+        } else {
+            println("Installation complete, ${parent.alias} is available in bash, but autocompletion was not installed because of an old version of bash.")
+        }
         println("Type `${parent.alias} <options>` from the commandline.")
         println("Restart bash for this to take effect, or run `. ~/.bashrc` in bash or `. ~/.zshrc` in zsh to re-initialise your shell now")
+        return ExitCodes.SUCCESS
+    }
+
+    private fun declaredBashVersion(): String = execCommand("bash -c 'echo \$BASH_VERSION'")
+
+    private fun installedShell(): ShellType {
+        val path = execCommand("bash -c 'echo \$SHELL'")
+        return when {
+            path.endsWith("/zsh") -> ShellType.ZSH
+            path.endsWith("/bash") -> ShellType.BASH
+            else -> ShellType.OTHER
+        }
+    }
+
+    private enum class ShellType {
+        ZSH, BASH, OTHER
+    }
+
+    private fun execCommand(command: String): String {
+        val process = ProcessBuilder(command)
+        return IOUtils.toString(process.start().inputStream, Charsets.UTF_8)
     }
 
     fun checkForAutoCompleteUpdate() {
@@ -127,8 +170,7 @@ private class ShellExtensionsGenerator(val parent: CordaCliWrapper) {
 class InstallShellExtensionsParser(private val cliWrapper: CordaCliWrapper) : CliWrapperBase("install-shell-extensions", "Install alias and autocompletion for bash and zsh") {
     private val generator = ShellExtensionsGenerator(cliWrapper)
     override fun runProgram(): Int {
-        generator.installShellExtensions()
+        return generator.installShellExtensions()
-        return ExitCodes.SUCCESS
     }
 
     fun updateShellExtensions() = generator.checkForAutoCompleteUpdate()