如何确定进程在 kotlin 脚本中失败的原因

Question

我正在开发一个 kotlin 脚本，它在运行所在的平台上执行代码。使用脚本中的此方法调用平台代码：

fun exec(command: String, vararg arguments: String, runLive: Boolean = !isDebug): OutputStream {
    val allArgs = arguments.joinToString(" ")

    if (runLive) {
        val process = Runtime.getRuntime().exec(command, arguments)
        val exitCode = process.waitFor()

        if (exitCode != 0) {
            val platformError = String(BufferedInputStream(process.errorStream).readAllBytes(), Charset.defaultCharset())
            throw IllegalStateException("Execution of '$command $allArgs' failed with exit code $exitCode!\n$platformError")
        }

        return process.outputStream
    } else {
        println("$command $allArgs")

        return object : OutputStream() {
            override fun write(b: Int) {
                println("dummy $b")
            }
        }
    }
}

在脚本中，我尝试使用此调用获取 git 存储库的所有标签：

exec(command = "git", "tag", runLive = true)

命令失败时，如何读取process.errorStream？现在的输出不可读，脚本失败显示：

java.lang.IllegalStateException: Execution of 'git tag' failed with exit code 1!

    at Snap_tag_main.exec(snap-tag.main.kts:75)
    at Snap_tag_main.<init>(snap-tag.main.kts:64)

Answer 1

并非所有命令在显示错误时都使用错误流。解决方案是像这样同时引入输入流和输出流：

        if (exitCode != 0) {
            val platformMessages = """
                ${String(BufferedInputStream(process.inputStream).readAllBytes(), Charset.defaultCharset())}
                ${String(BufferedInputStream(process.errorStream).readAllBytes(), Charset.defaultCharset())}
            """.trimIndent().trim()

            throw IllegalStateException("Execution of '$command $allArgs' failed with exit code $exitCode!\n$platformMessages\n---")
        }

失败消息现在看起来像

java.lang.IllegalStateException: Execution of 'git tag' failed with exit code 1!
usage: git [--version] [--help] [-C <path>] [-c <name>=<value>]
           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]
           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
           [--super-prefix=<path>] [--config-env=<name>=<envvar>]
           <command> [<args>]

These are common Git commands used in various situations:

start a working area (see also: git help tutorial)
   clone     Clone a repository into a new directory
   init      Create an empty Git repository or reinitialize an existing one

work on the current change (see also: git help everyday)
   add       Add file contents to the index
   mv        Move or rename a file, a directory, or a symlink
   restore   Restore working tree files
   rm        Remove files from the working tree and from the index

examine the history and state (see also: git help revisions)
   bisect    Use binary search to find the commit that introduced a bug
   diff      Show changes between commits, commit and working tree, etc
   grep      Print lines matching a pattern
   log       Show commit logs
   show      Show various types of objects
   status    Show the working tree status

grow, mark and tweak your common history
   branch    List, create, or delete branches
   commit    Record changes to the repository
   merge     Join two or more development histories together
   rebase    Reapply commits on top of another base tip
   reset     Reset current HEAD to the specified state
   switch    Switch branches
   tag       Create, list, delete or verify a tag object signed with GPG

collaborate (see also: git help workflows)
   fetch     Download objects and refs from another repository
   pull      Fetch from and integrate with another repository or a local branch
   push      Update remote refs along with associated objects

'git help -a' and 'git help -g' list available subcommands and some
concept guides. See 'git help <command>' or 'git help <concept>'
to read about a specific subcommand or concept.
See 'git help git' for an overview of the system.
---
    at Snap_tag_main.exec(snap-tag.main.kts:82)
    at Snap_tag_main.<init>(snap-tag.main.kts:66)

如何确定进程在 kotlin 脚本中失败的原因

How to determine why process fails in kotlin script

jvm

kotlin-script