stty option-parsing minor code cleanups

[Paul Eggert]

While fixing the aforementioned bugs I noticed some minor cleanup
possibilities in stty.c and installed this patch.

2004-09-05  Paul Eggert  <address@hidden>

        * src/stty.c (recover_mode): Arg is now char const *, not char *.
        (main): Use STDIN_FILENO, not 0.
        Simplify option-parsing code a tad.

Index: stty.c
===================================================================
RCS file: /home/eggert/coreutils/cu/src/stty.c,v
retrieving revision 1.126
retrieving revision 1.127
diff -p -u -r1.126 -r1.127
--- stty.c      5 Sep 2004 07:21:42 -0000       1.126
+++ stty.c      5 Sep 2004 07:27:51 -0000       1.127
@@ -405,7 +405,7 @@ static struct control_info control_info[
 
 static char const *visible (cc_t ch);
 static unsigned long int baud_to_value (speed_t speed);
-static bool recover_mode (char *arg, struct termios *mode);
+static bool recover_mode (char const *arg, struct termios *mode);
 static int screen_columns (void);
 static bool set_mode (struct mode_info *info, bool reversed,
                      struct termios *mode);
@@ -826,7 +826,7 @@ main (int argc, char **argv)
     }
   else
     {
-      fd = 0;
+      fd = STDIN_FILENO;
       device_name = _("standard input");
     }
 
@@ -846,27 +846,24 @@ main (int argc, char **argv)
 
   speed_was_set = false;
   require_set_attr = false;
-  k = 1;
-  while (k < argc)
+  for (k = 1; k < argc; k++)
     {
+      char const *arg = argv[k];
       bool match_found = false;
       bool reversed = false;
       int i;
 
-      if (argv[k] == 0)
-       {
-         k++;
-         continue;
-       }
+      if (! arg)
+       continue;
 
-      if (argv[k][0] == '-')
+      if (arg[0] == '-')
        {
-         ++argv[k];
+         ++arg;
          reversed = true;
        }
       for (i = 0; mode_info[i].name != NULL; ++i)
        {
-         if (STREQ (argv[k], mode_info[i].name))
+         if (STREQ (arg, mode_info[i].name))
            {
              match_found = set_mode (&mode_info[i], reversed, &mode);
              require_set_attr = true;
@@ -875,18 +872,18 @@ main (int argc, char **argv)
        }
       if (!match_found & reversed)
        {
-         error (0, 0, _("invalid argument `%s'"), --argv[k]);
+         error (0, 0, _("invalid argument `%s'"), arg - 1);
          usage (EXIT_FAILURE);
        }
       if (!match_found)
        {
          for (i = 0; control_info[i].name != NULL; ++i)
            {
-             if (STREQ (argv[k], control_info[i].name))
+             if (STREQ (arg, control_info[i].name))
                {
                  if (k == argc - 1)
                    {
-                     error (0, 0, _("missing argument to `%s'"), argv[k]);
+                     error (0, 0, _("missing argument to `%s'"), arg);
                      usage (EXIT_FAILURE);
                    }
                  match_found = true;
@@ -899,11 +896,11 @@ main (int argc, char **argv)
        }
       if (!match_found)
        {
-         if (STREQ (argv[k], "ispeed"))
+         if (STREQ (arg, "ispeed"))
            {
              if (k == argc - 1)
                {
-                 error (0, 0, _("missing argument to `%s'"), argv[k]);
+                 error (0, 0, _("missing argument to `%s'"), arg);
                  usage (EXIT_FAILURE);
                }
              ++k;
@@ -911,11 +908,11 @@ main (int argc, char **argv)
              speed_was_set = true;
              require_set_attr = true;
            }
-         else if (STREQ (argv[k], "ospeed"))
+         else if (STREQ (arg, "ospeed"))
            {
              if (k == argc - 1)
                {
-                 error (0, 0, _("missing argument to `%s'"), argv[k]);
+                 error (0, 0, _("missing argument to `%s'"), arg);
                  usage (EXIT_FAILURE);
                }
              ++k;
@@ -924,30 +921,30 @@ main (int argc, char **argv)
              require_set_attr = true;
            }
 #ifdef TIOCGWINSZ
-         else if (STREQ (argv[k], "rows"))
+         else if (STREQ (arg, "rows"))
            {
              if (k == argc - 1)
                {
-                 error (0, 0, _("missing argument to `%s'"), argv[k]);
+                 error (0, 0, _("missing argument to `%s'"), arg);
                  usage (EXIT_FAILURE);
                }
              ++k;
              set_window_size (integer_arg (argv[k], INT_MAX), -1,
                               fd, device_name);
            }
-         else if (STREQ (argv[k], "cols")
-                  || STREQ (argv[k], "columns"))
+         else if (STREQ (arg, "cols")
+                  || STREQ (arg, "columns"))
            {
              if (k == argc - 1)
                {
-                 error (0, 0, _("missing argument to `%s'"), argv[k]);
+                 error (0, 0, _("missing argument to `%s'"), arg);
                  usage (EXIT_FAILURE);
                }
              ++k;
              set_window_size (-1, integer_arg (argv[k], INT_MAX),
                               fd, device_name);
            }
-         else if (STREQ (argv[k], "size"))
+         else if (STREQ (arg, "size"))
            {
              max_col = screen_columns ();
              current_col = 0;
@@ -955,12 +952,12 @@ main (int argc, char **argv)
            }
 #endif
 #ifdef HAVE_C_LINE
-         else if (STREQ (argv[k], "line"))
+         else if (STREQ (arg, "line"))
            {
              unsigned long int value;
              if (k == argc - 1)
                {
-                 error (0, 0, _("missing argument to `%s'"), argv[k]);
+                 error (0, 0, _("missing argument to `%s'"), arg);
                  usage (EXIT_FAILURE);
                }
              ++k;
@@ -970,28 +967,27 @@ main (int argc, char **argv)
              require_set_attr = true;
            }
 #endif
-         else if (STREQ (argv[k], "speed"))
+         else if (STREQ (arg, "speed"))
            {
              max_col = screen_columns ();
              display_speed (&mode, false);
            }
-         else if (string_to_baud (argv[k]) != (speed_t) -1)
+         else if (string_to_baud (arg) != (speed_t) -1)
            {
-             set_speed (both_speeds, argv[k], &mode);
+             set_speed (both_speeds, arg, &mode);
              speed_was_set = true;
              require_set_attr = true;
            }
          else
            {
-             if (! recover_mode (argv[k], &mode))
+             if (! recover_mode (arg, &mode))
                {
-                 error (0, 0, _("invalid argument `%s'"), argv[k]);
+                 error (0, 0, _("invalid argument `%s'"), arg);
                  usage (EXIT_FAILURE);
                }
              require_set_attr = true;
            }
        }
-      k++;
     }
 
   if (require_set_attr)
@@ -1651,7 +1647,7 @@ display_recoverable (struct termios *mod
 }
 
 static bool
-recover_mode (char *arg, struct termios *mode)
+recover_mode (char const *arg, struct termios *mode)
 {
   size_t i;
   int n;