/* Program name management.

   Copyright (C) 2016-2018 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */

#include "getprogname.h"

#include <errno.h> /* get program_invocation_name declaration */

#include <stdlib.h> /* get __argv declaration */

#ifdef _AIX

# include <unistd.h>

# include <procinfo.h>

# include <string.h>

#endif

#ifdef __MVS__

# ifndef _OPEN_SYS

#  define _OPEN_SYS

# endif

# include <string.h>

# include <sys/ps.h>

#endif

#ifdef __hpux

# include <unistd.h>

# include <sys/param.h>

# include <sys/pstat.h>

# include <string.h>

#endif

#ifdef __sgi

# include <string.h>

# include <unistd.h>

# include <stdio.h>

# include <fcntl.h>

# include <sys/procfs.h>

#endif

#include "dirname.h"

#ifndef HAVE_GETPROGNAME             /* not Mac OS X, FreeBSD, NetBSD, OpenBSD >= 5.4, Cygwin */

char const *

getprogname (void)

{

# if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME                /* glibc, BeOS */

  /* https://www.gnu.org/software/libc/manual/html_node/Error-Messages.html */

  return program_invocation_short_name;

# elif HAVE_DECL_PROGRAM_INVOCATION_NAME                    /* glibc, BeOS */

  /* https://www.gnu.org/software/libc/manual/html_node/Error-Messages.html */

  return last_component (program_invocation_name);

# elif HAVE_GETEXECNAME                                     /* Solaris */

  /* https://docs.oracle.com/cd/E19253-01/816-5168/6mbb3hrb1/index.html */

  const char *p = getexecname ();

  if (!p)

    p = "?";

  return last_component (p);

# elif HAVE_DECL___ARGV                                     /* mingw, MSVC */

  /* https://msdn.microsoft.com/en-us/library/dn727674.aspx */

  const char *p = __argv && __argv[0] ? __argv[0] : "?";

  return last_component (p);

# elif HAVE_VAR___PROGNAME                                  /* OpenBSD, QNX */

  /* https://man.openbsd.org/style.9 */

  /* http://www.qnx.de/developers/docs/6.5.0/index.jsp?topic=%2Fcom.qnx.doc.neutrino_lib_ref%2Fp%2F__progname.html */

  /* Be careful to declare this only when we absolutely need it

     (OpenBSD 5.1), rather than when it's available.  Otherwise,

     its mere declaration makes program_invocation_short_name

     malfunction (have zero length) with Fedora 25's glibc.  */

  extern char *__progname;

  const char *p = __progname;

  return p && p[0] ? p : "?";

# elif _AIX                                                 /* AIX */

  /* Idea by Bastien ROUCARIÈS,

     https://lists.gnu.org/r/bug-gnulib/2010-12/msg00095.html

     Reference: https://www.ibm.com/support/knowledgecenter/en/ssw_aix_61/com.ibm.aix.basetrf1/getprocs.htm

  */

  static char *p;

  static int first = 1;

  if (first)

    {

      first = 0;

      pid_t pid = getpid ();

      struct procentry64 procs;

      p = (0 < getprocs64 (&procs, sizeof procs, NULL, 0, &pid, 1)

           ? strdup (procs.pi_comm)

           : NULL);

      if (!p)

        p = "?";

    }

  return p;

# elif defined __hpux

  static char *p;

  static int first = 1;

  if (first)

    {

      first = 0;

      pid_t pid = getpid ();

      struct pst_status status;

      p = (0 < pstat_getproc (&status, sizeof status, 0, pid)

           ? strdup (status.pst_ucomm)

           : NULL);

      if (!p)

        p = "?";

    }

  return p;

# elif __MVS__                                              /* z/OS */

  /* https://www.ibm.com/support/knowledgecenter/SSLTBW_2.1.0/com.ibm.zos.v2r1.bpxbd00/rtwgetp.htm */

  static char *p = "?";

  static int first = 1;

  if (first)

    {

      pid_t pid = getpid ();

      int token;

      W_PSPROC buf;

      first = 0;

      memset (&buf, 0, sizeof(buf));

      buf.ps_cmdptr    = (char *) malloc (buf.ps_cmdlen    = PS_CMDBLEN_LONG);

      buf.ps_conttyptr = (char *) malloc (buf.ps_conttylen = PS_CONTTYBLEN);

      buf.ps_pathptr   = (char *) malloc (buf.ps_pathlen   = PS_PATHBLEN);

      if (buf.ps_cmdptr && buf.ps_conttyptr && buf.ps_pathptr)

        {

          for (token = 0; token >= 0;

               token = w_getpsent (token, &buf, sizeof(buf)))

            {

              if (token > 0 && buf.ps_pid == pid)

                {

                  char *s = strdup (last_component (buf.ps_pathptr));

                  if (s)

                    p = s;

                  break;

                }

            }

        }

      free (buf.ps_cmdptr);

      free (buf.ps_conttyptr);

      free (buf.ps_pathptr);

    }

  return p;

# elif defined __sgi                                        /* IRIX */

  char filename[50];

  int fd;

  sprintf (filename, "/proc/pinfo/%d", (int) getpid ());

  fd = open (filename, O_RDONLY);

  if (0 <= fd)

    {

      prpsinfo_t buf;

      int ioctl_ok = 0 <= ioctl (fd, PIOCPSINFO, &buf;;

      close (fd);

      if (ioctl_ok)

        {

          char *name = buf.pr_fname;

          size_t namesize = sizeof buf.pr_fname;

          char *namenul = memchr (name, '\0', namesize);

          size_t namelen = namenul ? namenul - name : namesize;

          char *namecopy = malloc (namelen + 1);

          if (namecopy)

            {

              namecopy[namelen] = 0;

              return memcpy (namecopy, name, namelen);

            }

        }

    }

  return NULL;

# else

#  error "getprogname module not ported to this OS"

# endif

}

#endif

/*

 * Hey Emacs!

 * Local Variables:

 * coding: utf-8

 * End:

 */