Initial release

README.md

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+## PIJ - Run process tree in a job and wait for completion.
+
+## Usage
+`pij my-program.exe arguments...`
+
+## Purpose
+Use it when you want to run `my-program.exe` in a batch file, but
+my-program.exe starts another process(es) and returns before they
+complete, which is not what you want: batch file should continue only
+when all additional processes also exit. PIJ runs initial process in a
+job and waits for this job to become empty, before exiting.
+
+## Result code (ERRORLEVEL)
+PIJ terminates with non-zero exit code if there's some problem during
+initial process creation or waiting phase. Zero exit code is returned
+when the last process in the job exits.
+
+## Restrictions
+All arguments are passed to CreateProcess'es lpCommandLine, hence some
+restrictions on what you can start: it should be a real EXE file
+(please start cmd.exe if you want to run another batch file), standard
+directories and PATH are used, registry AppPaths aren't.
+
+## Author
+Written by Anton Kovalenko <anton@sw4me.com>. My code is public domain.
+Uses some code by Raymond Chen.

build.cmd

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+x86_64-w64-mingw32-gcc -O2 -s pij.c pijhelp.cc -o pij.exe -DUNICODE

pij.c

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+#ifndef UNICODE
+#define UNICODE
+#endif
+
+#include <windows.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+// Skip initial argument in a command line.  Adapted from my winserv
+// http://www.sw4me.com/wiki/Winserv
+static LPTSTR skip_arg(LPTSTR p)
+{
+  int inquote, slashes;
+
+  // skip spaces
+  while (isspace(*p)) { p++; }
+  if (*p == TEXT('\0')) { return p; }
+  inquote = 0; slashes = 0;
+  // we found where the argument begins
+  for (;;) {
+    while (*p == TEXT('\\')) {
+      slashes++;
+      p++;
+    }
+    if (*p == TEXT('"')) {
+      if ((slashes & 1) == 0) {
+	if ((inquote) && (p[1] == TEXT('"'))) {
+	  p++;
+	} else {
+	  inquote = !inquote;
+	}
+      }
+    }
+    slashes=0;
+    if ((*p == TEXT('\0')) || (!inquote && isspace(*p))) {
+      while (isspace(*p))
+	p++;
+      return p;
+    }
+    p++;
+  }
+}
+
+// Terminate unsuccessfully with an error message
+static void Fail(const char *desc) {
+  fprintf(stderr, "Error %u in %s\n", GetLastError(), desc);
+  exit(1);
+}
+
+// Raymond Chen's CreateProcessInJob
+// see https://devblogs.microsoft.com/oldnewthing/20131209-00/?p=2433
+BOOL CreateProcessInJob(
+			HANDLE hJob,
+			LPCTSTR lpApplicationName,
+			LPTSTR lpCommandLine,
+			LPSECURITY_ATTRIBUTES lpProcessAttributes,
+			LPSECURITY_ATTRIBUTES lpThreadAttributes,
+			BOOL bInheritHandles,
+			DWORD dwCreationFlags,
+			LPVOID lpEnvironment,
+			LPCTSTR lpCurrentDirectory,
+			LPSTARTUPINFO lpStartupInfo,
+			LPPROCESS_INFORMATION ppi)
+{
+  BOOL fRc = CreateProcess(
+			   lpApplicationName,
+			   lpCommandLine,
+			   lpProcessAttributes,
+			   lpThreadAttributes,
+			   bInheritHandles,
+			   dwCreationFlags | CREATE_SUSPENDED,
+			   lpEnvironment,
+			   lpCurrentDirectory,
+			   lpStartupInfo,
+			   ppi);
+  if (fRc) {
+    fRc = AssignProcessToJobObject(hJob, ppi->hProcess);
+    if (fRc && !(dwCreationFlags & CREATE_SUSPENDED)) {
+      fRc = ResumeThread(ppi->hThread) != (DWORD)-1;
+    }
+    if (!fRc) {
+      TerminateProcess(ppi->hProcess, 0);
+      CloseHandle(ppi->hProcess);
+      CloseHandle(ppi->hThread);
+      ppi->hProcess = ppi->hThread = NULL;
+    }
+  }
+  return fRc;
+}
+
+// defined in pijhelp.cc, so I can use C++ raw literals
+extern const char *Help;
+
+
+int main(int argc, char*argv[])
+{
+  if (argc <= 1) {
+    printf("%s",Help);
+    exit(0);
+  }
+  LPTSTR cmdline = GetCommandLineW();
+  LPTSTR restCmdLine = skip_arg(cmdline);
+  HANDLE hJob = CreateJobObject(NULL,NULL);
+  if (hJob == NULL) {
+    Fail("CreateJobObject");
+  }
+  HANDLE hPort = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 1);
+  if (hPort == NULL) {
+    Fail("CreateIoCompletionPort");
+  }
+
+  // see https://devblogs.microsoft.com/oldnewthing/20130405-00/?p=4743
+  JOBOBJECT_ASSOCIATE_COMPLETION_PORT jacp;
+  jacp.CompletionKey = hJob;
+  jacp.CompletionPort = hPort;
+  if (!SetInformationJobObject(hJob,
+			       JobObjectAssociateCompletionPortInformation,
+			       &jacp, sizeof(jacp))) {
+    Fail("SetInformationJobObject(JobObjectAssociateCompletionPortInformation)");
+  }
+
+  STARTUPINFO si = { sizeof si };
+  PROCESS_INFORMATION pi;
+  if (!CreateProcessInJob(hJob,
+			  NULL,
+			  restCmdLine,
+			  NULL,
+			  NULL,
+			  FALSE,
+			  0,
+			  NULL,
+			  NULL,
+			  &si,
+			  &pi)) {
+    Fail("CreateProcess");
+  }
+  CloseHandle(pi.hProcess);
+  CloseHandle(pi.hThread);
+
+
+  DWORD completionCode;
+  ULONG_PTR completionKey;
+  LPOVERLAPPED overlapped;
+
+  for (;;) {
+    BOOL rc = GetQueuedCompletionStatus(hPort,
+					&completionCode,
+					&completionKey,
+					&overlapped,
+					INFINITE);
+    if (!rc) {
+      Fail("GetQueuedCompletionStatus");
+    }
+    if ((HANDLE)completionKey == hJob &&
+	completionCode == JOB_OBJECT_MSG_ACTIVE_PROCESS_ZERO) {
+      break;
+    }
+  }
+  CloseHandle(hJob);
+  return 0;
+}

pijhelp.cc

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+const char *Help = R"HELP(
+PIJ - Run process tree in a job and wait for completion.
+
+Usage:
+  pij my-program.exe arguments...
+
+Use it when you want to run my-program.exe in a batch file, but
+my-program.exe starts another process(es) and returns before they
+complete, which is not what you want: batch file should continue only
+when all additional processes also exit. PIJ runs initial process in a
+job and waits for this job to become empty, before exiting.
+
+PIJ terminates with non-zero exit code if there's some problem during
+initial process creation or waiting phase. Zero exit code is returned
+when the last process in the job exits.
+
+All arguments are passed to CreateProcess'es lpCommandLine, hence some
+restrictions on what you can start: it should be a real EXE file
+(please start cmd.exe if you want to run another batch file), standard
+directories and PATH are used, registry AppPaths aren't.
+
+Written by Anton Kovalenko <anton@sw4me.com>. Public domain.
+)HELP";
+