A framework for mhl program.

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2003 Free Software Foundation, Inc.
+
+   GNU Mailutils 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 2, or (at your option)
+   any later version.
+
+   GNU Mailutils 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 GNU Mailutils; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA  */
+
+/* MH mhl command */
+
+#include <mh.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+const char *argp_program_version = "mhl (" PACKAGE_STRING ")";
+static char doc[] = N_("GNU MH mhl\v"
+"Options marked with `*' are not yet implemented.\n"
+"Use -help to obtain the list of traditional MH options.");
+static char args_doc[] = N_("[files]");
+
+/* GNU options */
+static struct argp_option options[] = {
+  {"folder",     ARG_FOLDER,     N_("FOLDER"), 0,
+   N_("Specify folder to operate upon")},
+  { "bell",      ARG_BELL,       N_("BOOL"), OPTION_ARG_OPTIONAL,
+    N_("* Ring the bell at the end of each output page") },
+  {"nobell",     ARG_NOBELL,     NULL, OPTION_HIDDEN, "" },
+  { "clear",     ARG_CLEAR,      N_("BOOL"), OPTION_ARG_OPTIONAL,
+    N_("* Clear the screen after each page of output")},
+  {"noclear",    ARG_NOCLEAR,    NULL, OPTION_HIDDEN, "" },
+  {"form",       ARG_FORM,       N_("FILE"), 0,
+   N_("* Read format from given file")},
+  {"width",      ARG_WIDTH,      N_("NUMBER"), 0,
+   N_("* Set output width")},
+  {"length",     ARG_LENGTH,     N_("NUMBER"), 0,
+   N_("* Set output screen length")},
+  {"moreproc",   ARG_MOREPROC,   N_("PROG"), 0,
+   N_("Use given PROG instead of the default") },
+  {"nomoreproc", ARG_NOMOREPROC, NULL, 0,
+   N_("Disable use of moreproc program") },
+  { NULL }
+};
+   
+/* Traditional MH options */
+struct mh_option mh_option[] = {
+  { "bell",       1,  MH_OPT_BOOL },
+  { "clear",      1,  MH_OPT_BOOL },
+  { "form",       1,  MH_OPT_ARG, "formatfile"},
+  { "width",      1,  MH_OPT_ARG, "number"},
+  { "length",     1,  MH_OPT_ARG, "number"},
+  { "moreproc",   1,  MH_OPT_ARG, "program"},
+  { "nomoreproc", 3, },
+  { NULL }
+};
+
+static int interactive;  /* Using interactive output */
+static int bell = 1;     /* Ring the bell after each page of output */
+static int clear = 0;    /* Clear the screen after each page of output */
+static int length = 40;  /* Length of output page */
+static int width = 80;   /* Width of output page */
+static char *formfile = "mhl.format";
+static char *moreproc;
+static int nomoreproc;
+
+static int
+opt_handler (int key, char *arg, void *unused)
+{
+  switch (key)
+    {
+    case '+':
+    case ARG_FOLDER:
+      current_folder = arg;
+      break;
+
+    case ARG_BELL:
+      bell = is_true (arg);
+      break;
+      
+    case ARG_NOBELL:
+      bell = 0;
+      break;
+      
+    case ARG_CLEAR:
+      clear = is_true (arg);
+      break;
+      
+    case ARG_NOCLEAR:
+      clear = 0;
+      break;
+      
+    case ARG_FORM:
+      formfile = arg;
+      break;
+      
+    case ARG_WIDTH:
+      width = strtoul (arg, NULL, 0);
+      if (!width)
+	{
+	  mh_error (_("Invalid width"));
+	  exit (1);
+	}
+      break;
+      
+    case ARG_LENGTH:
+      length = strtoul (arg, NULL, 0);
+      if (!length)
+	{
+	  mh_error (_("Invalid length"));
+	  exit (1);
+	}
+      break;
+
+    case ARG_MOREPROC:
+      moreproc = arg;
+      break;
+      
+    case ARG_NOMOREPROC:
+      nomoreproc = 1;
+      break;
+      
+    default:
+      return 1;
+    }
+  return 0;
+}
+
+static stream_t
+open_output ()
+{
+  int rc;
+  stream_t output;
+  
+  if (interactive && !nomoreproc)
+    moreproc = mh_global_profile_get ("moreproc", getenv ("PAGER"));
+  else
+    moreproc = NULL;
+  
+  if (moreproc)
+    rc = prog_stream_create (&output, moreproc, MU_STREAM_WRITE);
+  else
+    rc = stdio_stream_create (&output, stdout, MU_STREAM_WRITE);
+
+  if (rc)
+    {
+      mh_error (_("cannot create output stream: %s"), mu_strerror (rc));
+      exit (1);
+    }
+
+  if ((rc = stream_open (output)))
+    {
+      mh_error (_("cannot open output stream: %s"), mu_strerror (rc));
+      exit (1);
+    }
+  return output;
+}
+
+static void
+list_message (char *name, stream_t output)
+{
+  stream_t input;
+  int rc;
+  char buf[512];
+  size_t n;
+
+  if (!name)
+    rc = stdio_stream_create (&input, stdin, 0);
+  else
+    rc = file_stream_create (&input, name, MU_STREAM_READ);
+  if (rc)
+    {
+      mh_error (_("cannot create input stream: %s"), mu_strerror (rc));
+      return;
+    }
+
+  if ((rc = stream_open (input)))
+    {
+      mh_error (_("cannot open input stream: %s"), mu_strerror (rc));
+      stream_destroy (&input, stream_get_owner (input));
+      return;
+    }
+
+  while (stream_sequential_readline (input, buf, sizeof buf, &n) == 0
+	 && n > 0)
+    stream_sequential_write (output, buf, n);
+
+  stream_close (input);
+  stream_destroy (&input, stream_get_owner (input));
+}
+
+int
+main (int argc, char **argv)
+{
+  int index;
+  stream_t output;
+  
+  interactive = isatty (1) && isatty (0);
+  
+  mu_init_nls ();
+  mh_argp_parse (argc, argv, options, mh_option, args_doc, doc,
+		 opt_handler, NULL, &index);
+
+  argc -= index;
+  argv += index;
+
+  if (argc == 0)
+    nomoreproc = 1;
+  
+  output = open_output ();
+  
+  if (argc == 0)
+    list_message (NULL, output);
+  else
+    while (argc--)
+      list_message (*argv++, output);
+  
+  return 0;
+}