od fixes for POSIX and FreeBSD compatibility

[Paul Eggert]

While looking at coreutils option processing I noticed that
"od" had a FIXME and a few other compatibility problems with
respect to POSIX and FreeBSD.  I installed the following patch
to fix the problems I found.

2004-09-06  Paul Eggert  <address@hidden>

        * NEWS: Describe the following.
        * doc/coreutils.texi (od invocation): Several changes for POSIX
        and FreeBSD compatibility.  Add support for XSI syntax
        (POSIX 1003.1-2004).  Rename -s[N] to -S N.  Remove documentation
        for -h.  -i is now -t dI (not d2) and -l is now -t dL (not d4).
        * src/od.c: Several changes for POSIX and FreeBSD compatibility.
        (COMMON_SHORT_OPTIONS): Add -B, -D, -e, -F, -H, -I, -L, -O, -s, -X.
        (long_options, main): --strings is now -S, not -s.
        (usage): Reflect the usage changes.
        (parse_old_offset): Do not issue a diagnostic on failure;
        callers now do this as necessary.
        (main): Support POSIX syntax.  Remove unused case 0 from getopt_long.
        Add support for new short options (many undocumented) for
        compatibility with FreeBSD.  Remove FIXME for -s; it's now
        POSIX-compatible.  Default format is now oS, not o2.

Index: NEWS
===================================================================
RCS file: /home/eggert/coreutils/cu/NEWS,v
retrieving revision 1.230
retrieving revision 1.231
diff -p -u -r1.230 -r1.231
--- NEWS        24 Aug 2004 07:36:36 -0000      1.230
+++ NEWS        6 Sep 2004 07:49:06 -0000       1.231
@@ -186,6 +186,28 @@ GNU coreutils NEWS                      
   The usual `--' operand is now supported by chroot, hostid, hostname,
   pwd, sync, and yes.
 
+  `od' now conforms to POSIX better, and is more compatible with BSD:
+
+    The older syntax "od [-abcdfilosx]... [FILE] [[+]OFFSET[.][b]]" now works
+    even without --traditional.  This is a change in behavior if there
+    are one or two operands and the last one begins with +, or if
+    there are two operands and the latter one begins with a digit.
+    For example, "od foo 10" and "od +10" now treat the last operand as
+    an offset, not as a file name.
+
+    -h is no longer documented, and may be withdrawn in future versions.
+    Use -x or -t x2 instead.
+
+    -i is now equivalent to -t dI (not -t d2), and
+    -l is now equivalent to -t dL (not -t d4).
+
+    -s is now equivalent to -t d2.  The old "-s[NUM]" or "-s NUM"
+    option has been renamed to "-S NUM".
+
+    The default output format is now -t oS, not -t o2, i.e., short int
+    rather than two-byte int.  This makes a difference only on hosts like
+    Cray systems where the C short int type requires more than two bytes.
+
   The stat option --filesystem has been renamed to --file-system, for
   consistency with POSIX "file system" and with cp and du --one-file-system.
 
Index: doc/coreutils.texi
===================================================================
RCS file: /home/eggert/coreutils/cu/doc/coreutils.texi,v
retrieving revision 1.204
retrieving revision 1.205
diff -p -u -r1.204 -r1.205
--- doc/coreutils.texi  6 Sep 2004 01:03:20 -0000       1.204
+++ doc/coreutils.texi  6 Sep 2004 07:47:04 -0000       1.205
@@ -1500,15 +1500,30 @@ Use @var{number} characters for line num
 (@samp{-} means standard input), or standard input if none are given.
 Synopses:
 
address@hidden
address@hidden
 od address@hidden@dots{} address@hidden@dots{}
-od --traditional address@hidden address@hidden address@hidden
address@hidden example
+od address@hidden address@hidden address@hidden
+od address@hidden@dots{} --traditional address@hidden address@hidden 
address@hidden
address@hidden smallexample
 
 Each line of output consists of the offset in the input, followed by
 groups of data from the file.  By default, @command{od} prints the offset in
-octal, and each group of file data is two bytes of input printed as a
-single octal number.
+octal, and each group of file data is a C @code{short int}'s worth of input
+printed as a single octal number.
+
+If @var{offset} is given, it specifies how many input bytes to skip
+before formatting and writing.  By default, it is interpreted as an
+octal number, but the optional trailing decimal point causes it to be
+interpretated as decimal.  If no decimal is specified and the offset
+begins with @samp{0x} or @samp{0X} it is interpreted as a hexadecimal
+number.  If there is a trailing @samp{b}, the number of bytes skipped
+will be @var{offset} multiplied by 512.
+
+If a command is of both the first and second forms, the second form is
+assumed if the last operand begins with @samp{+} or (if there are two
+operands) a digit.  For example, in @samp{od foo 10} and @samp{od +10}
+the @samp{10} is an offset, whereas in @samp{od 10} the @samp{10} is a
+file name.
 
 The program accepts the following options.  Also see @ref{Common options}.
 
@@ -1553,20 +1568,16 @@ by 1024, and @samp{m} by 1048576.
 Output at most @var{bytes} bytes of the input.  Prefixes and suffixes on
 @code{bytes} are interpreted as for the @option{-j} option.
 
address@hidden -s @var{n}
address@hidden -S @var{n}
 @itemx address@hidden
address@hidden -s
address@hidden -S
 @opindex --strings
 @cindex string constants, outputting
 Instead of the normal output, output only @dfn{string constants}: at
 least @var{n} consecutive @acronym{ASCII} graphic characters,
 followed by a null (zero) byte.
 
-If @var{n} is omitted with @option{--strings}, the default is 3.  On
-older systems, @sc{gnu} @command{od} instead supports an obsolete
-option @address@hidden, where @var{n} also defaults to 3.
address@hidden 1003.1-2001 (@pxref{Standards conformance}) does not allow
address@hidden without an argument; use @option{--strings} instead.
+If @var{n} is omitted with @option{--strings}, the default is 3.
 
 @item -t @var{type}
 @itemx address@hidden
@@ -1669,48 +1680,48 @@ specification options.  These options ac
 
 @item -a
 @opindex -a
-Output as named characters.  Equivalent to @option{-ta}.
+Output as named characters.  Equivalent to @samp{-t a}.
 
 @item -b
 @opindex -b
-Output as octal bytes.  Equivalent to @option{-toC}.
+Output as octal bytes.  Equivalent to @samp{-t o1}.
 
 @item -c
 @opindex -c
 Output as @acronym{ASCII} characters or backslash escapes.  Equivalent to
address@hidden
address@hidden c}.
 
 @item -d
 @opindex -d
-Output as unsigned decimal shorts.  Equivalent to @option{-tu2}.
+Output as unsigned decimal two-byte units.  Equivalent to @samp{-t u2}.
 
 @item -f
 @opindex -f
-Output as floats.  Equivalent to @option{-tfF}.
-
address@hidden -h
address@hidden -h
-Output as hexadecimal shorts.  Equivalent to @option{-tx2}.
+Output as floats.  Equivalent to @samp{-t fF}.
 
 @item -i
 @opindex -i
-Output as decimal shorts.  Equivalent to @option{-td2}.
+Output as decimal ints.  Equivalent to @samp{-t dI}.
 
 @item -l
 @opindex -l
-Output as decimal longs.  Equivalent to @option{-td4}.
+Output as decimal long ints.  Equivalent to @samp{-t dL}.
 
 @item -o
 @opindex -o
-Output as octal shorts.  Equivalent to @option{-to2}.
+Output as octal two-byte units.  Equivalent to @option{-t o2}.
+
address@hidden -s
address@hidden -s
+Output as decimal two-byte units.  Equivalent to @option{-t d2}.
 
 @item -x
 @opindex -x
-Output as hexadecimal shorts.  Equivalent to @option{-tx2}.
+Output as hexadecimal two-byte units.  Equivalent to @samp{-t x2}.
 
 @item --traditional
 @opindex --traditional
-Recognize the non-option arguments that traditional @command{od}
+Recognize the non-option label argument that traditional @command{od}
 accepted.  The following syntax:
 
 @smallexample
@@ -1719,14 +1730,8 @@ od --traditional address@hidden address@hidden
 
 @noindent
 can be used to specify at most one file and optional arguments
-specifying an offset and a pseudo-start address, @var{label}.  By
-default, @var{offset} is interpreted as an octal number specifying how
-many input bytes to skip before formatting and writing.  The optional
-trailing decimal point forces the interpretation of @var{offset} as a
-decimal number.  If no decimal is specified and the offset begins with
address@hidden or @samp{0X} it is interpreted as a hexadecimal number.  If
-there is a trailing @samp{b}, the number of bytes skipped will be
address@hidden multiplied by 512.  The @var{label} argument is interpreted
+specifying an offset and a pseudo-start address, @var{label}.
+The @var{label} argument is interpreted
 just like @var{offset}, but it specifies an initial pseudo-address.  The
 pseudo-addresses are displayed in parentheses following any normal
 address.
Index: src/od.c
===================================================================
RCS file: /home/eggert/coreutils/cu/src/od.c,v
retrieving revision 1.150
retrieving revision 1.151
diff -p -u -r1.150 -r1.151
--- src/od.c    3 Aug 2004 14:38:53 -0000       1.150
+++ src/od.c    6 Sep 2004 07:46:43 -0000       1.151
@@ -265,7 +265,7 @@ static enum size_spec integral_type_size
 #define MAX_FP_TYPE_SIZE sizeof (LONG_DOUBLE)
 static enum size_spec fp_type_size[MAX_FP_TYPE_SIZE + 1];
 
-#define COMMON_SHORT_OPTIONS "A:N:abcdfhij:lot:vx"
+#define COMMON_SHORT_OPTIONS "A:aBbcDdeFfHhIij:LlN:OoS:st:vXx"
 
 /* For long options that have no equivalent short option, use a
    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
@@ -281,7 +281,7 @@ static struct option const long_options[
   {"read-bytes", required_argument, NULL, 'N'},
   {"format", required_argument, NULL, 't'},
   {"output-duplicates", no_argument, NULL, 'v'},
-  {"strings", optional_argument, NULL, 's'},
+  {"strings", optional_argument, NULL, 'S'},
   {"traditional", no_argument, NULL, TRADITIONAL_OPTION},
   {"width", optional_argument, NULL, 'w'},
 
@@ -300,9 +300,10 @@ usage (int status)
     {
       printf (_("\
 Usage: %s [OPTION]... [FILE]...\n\
-  or:  %s --traditional [FILE] [[+]OFFSET [[+]LABEL]]\n\
+  or:  %s [-abcdfilosx]... [FILE] [[+]OFFSET[.][b]]\n\
+  or:  %s --traditional [OPTION]... [FILE] [[+]OFFSET[.][b] 
[+][LABEL][.][b]]\n\
 "),
-             program_name, program_name);
+             program_name, program_name, program_name);
       fputs (_("\n\
 Write an unambiguous representation, octal bytes by default,\n\
 of FILE to standard output.  With more than one FILE argument,\n\
@@ -319,7 +320,7 @@ All arguments to long options are mandat
 "), stdout);
       fputs (_("\
   -N, --read-bytes=BYTES      limit dump to BYTES input bytes\n\
-  -s, --strings[=BYTES]       output strings of at least BYTES graphic chars\n\
+  -S, --strings[=BYTES]       output strings of at least BYTES graphic chars\n\
   -t, --format=TYPE           select output format or formats\n\
   -v, --output-duplicates     do not use * to mark line suppression\n\
   -w, --width[=BYTES]         output BYTES bytes per output line\n\
@@ -331,24 +332,26 @@ All arguments to long options are mandat
 \n\
 Traditional format specifications may be intermixed; they accumulate:\n\
   -a   same as -t a,  select named characters\n\
-  -b   same as -t oC, select octal bytes\n\
+  -b   same as -t o1, select octal bytes\n\
   -c   same as -t c,  select ASCII characters or backslash escapes\n\
-  -d   same as -t u2, select unsigned decimal shorts\n\
+  -d   same as -t u2, select unsigned decimal 2-byte units\n\
 "), stdout);
       fputs (_("\
   -f   same as -t fF, select floats\n\
-  -h   same as -t x2, select hexadecimal shorts\n\
-  -i   same as -t d2, select decimal shorts\n\
-  -l   same as -t d4, select decimal longs\n\
-  -o   same as -t o2, select octal shorts\n\
-  -x   same as -t x2, select hexadecimal shorts\n\
+  -i   same as -t dI, select decimal ints\n\
+  -l   same as -t dL, select decimal longs\n\
+  -o   same as -t o2, select octal 2-byte units\n\
+  -s   same as -t d2, select decimal 2-byte units\n\
+  -x   same as -t x2, select hexadecimal 2-byte units\n\
 "), stdout);
       fputs (_("\
 \n\
-For older syntax (second call format), OFFSET means -j OFFSET.  LABEL\n\
-is the pseudo-address at first byte printed, incremented when dump is\n\
-progressing.  For OFFSET and LABEL, a 0x or 0X prefix indicates\n\
-hexadecimal, suffixes may be . for octal and b for multiply by 512.\n\
+If first and second call formats both apply, the second format is assumed\n\
+if the last operand begins with + or (if there are 2 operands) a digit.\n\
+An OFFSET operand means -j OFFSET.  LABEL is the pseudo-address\n\
+at first byte printed, incremented when dump is progressing.\n\
+For OFFSET and LABEL, a 0x or 0X prefix indicates hexadecimal;\n\
+suffixes may be . for octal and b for multiply by 512.\n\
 \n\
 TYPE is made up of one or more of these specifications:\n\
 \n\
@@ -1308,7 +1311,6 @@ static bool
 parse_old_offset (const char *s, uintmax_t *offset)
 {
   int radix;
-  enum strtol_error s_err;
 
   if (*s == '\0')
     return false;
@@ -1330,13 +1332,7 @@ parse_old_offset (const char *s, uintmax
        radix = 8;
     }
 
-  s_err = xstrtoumax (s, NULL, radix, offset, "Bb");
-  if (s_err != LONGINT_OK)
-    {
-      STRTOL_FAIL_WARN (s, _("old-style offset"), s_err);
-      return false;
-    }
-  return true;
+  return xstrtoumax (s, NULL, radix, offset, "Bb") == LONGINT_OK;
 }
 
 /* Read a chunk of size BYTES_PER_BLOCK from the input files, write the
@@ -1553,11 +1549,12 @@ main (int argc, char **argv)
   size_t i;
   int l_c_m;
   size_t desired_width IF_LINT (= 0);
+  bool modern = false;
   bool width_specified = false;
   bool ok = true;
   char const *short_options = (posix2_version () < 200112
-                              ? COMMON_SHORT_OPTIONS "s::w::"
-                              : COMMON_SHORT_OPTIONS "s:w:");
+                              ? COMMON_SHORT_OPTIONS "w::"
+                              : COMMON_SHORT_OPTIONS "w:");
 
   /* The old-style `pseudo starting address' to be printed in parentheses
      after any true address.  */
@@ -1611,10 +1608,8 @@ main (int argc, char **argv)
 
       switch (c)
        {
-       case 0:
-         break;
-
        case 'A':
+         modern = true;
          switch (optarg[0])
            {
            case 'd':
@@ -1646,12 +1641,14 @@ it must be one character from [doxn]"),
          break;
 
        case 'j':
+         modern = true;
          s_err = xstrtoumax (optarg, NULL, 0, &n_bytes_to_skip, "bkm");
          if (s_err != LONGINT_OK)
            STRTOL_FATAL_ERROR (optarg, _("skip argument"), s_err);
          break;
 
        case 'N':
+         modern = true;
          limit_bytes_to_format = true;
 
          s_err = xstrtoumax (optarg, NULL, 0, &max_bytes_to_format, "bkm");
@@ -1659,7 +1656,8 @@ it must be one character from [doxn]"),
            STRTOL_FATAL_ERROR (optarg, _("limit argument"), s_err);
          break;
 
-       case 's':
+       case 'S':
+         modern = true;
          if (optarg == NULL)
            string_min = 3;
          else
@@ -1679,10 +1677,12 @@ it must be one character from [doxn]"),
          break;
 
        case 't':
+         modern = true;
          ok &= decode_format_string (optarg);
          break;
 
        case 'v':
+         modern = true;
          abbreviate_duplicate_blocks = false;
          break;
 
@@ -1693,7 +1693,9 @@ it must be one character from [doxn]"),
          /* The next several cases map the traditional format
             specification options to the corresponding modern format
             specs.  GNU od accepts any combination of old- and
-            new-style options.  Format specification options accumulate.  */
+            new-style options.  Format specification options accumulate.
+            The obsolescent and undocumented formats are compatible
+            with FreeBSD 4.10 od.  */
 
 #define CASE_OLD_ARG(old_char,new_string)              \
        case old_char:                                  \
@@ -1701,26 +1703,29 @@ it must be one character from [doxn]"),
          break
 
          CASE_OLD_ARG ('a', "a");
-         CASE_OLD_ARG ('b', "oC");
+         CASE_OLD_ARG ('b', "o1");
          CASE_OLD_ARG ('c', "c");
+         CASE_OLD_ARG ('D', "u4"); /* obsolescent and undocumented */
          CASE_OLD_ARG ('d', "u2");
+       case 'F': /* obsolescent and undocumented alias */
+         CASE_OLD_ARG ('e', "fD"); /* obsolescent and undocumented */
          CASE_OLD_ARG ('f', "fF");
-         CASE_OLD_ARG ('h', "x2");
-         CASE_OLD_ARG ('i', "d2");
-         CASE_OLD_ARG ('l', "d4");
+       case 'X': /* obsolescent and undocumented alias */
+         CASE_OLD_ARG ('H', "x4"); /* obsolescent and undocumented */
+         CASE_OLD_ARG ('i', "dI");
+       case 'I': case 'L': /* obsolescent and undocumented aliases */
+         CASE_OLD_ARG ('l', "dL");
+         CASE_OLD_ARG ('O', "o4"); /* obsolesent and undocumented */
+       case 'B': /* obsolescent and undocumented alias */
          CASE_OLD_ARG ('o', "o2");
+         CASE_OLD_ARG ('s', "d2");
+       case 'h': /* obsolescent and undocumented alias */
          CASE_OLD_ARG ('x', "x2");
 
-         /* FIXME: POSIX 1003.1-2001 with XSI requires this:
-
-            CASE_OLD_ARG ('s', "d2");
-
-            for the traditional syntax, but this conflicts with case
-            's' above. */
-
 #undef CASE_OLD_ARG
 
        case 'w':
+         modern = true;
          width_specified = true;
          if (optarg == NULL)
            {
@@ -1761,55 +1766,57 @@ it must be one character from [doxn]"),
      0 to 3 remaining command line arguments;  handle each case
      separately.
        od [file] [[+]offset[.][b] [[+]label[.][b]]]
-     The offset and pseudo_start have the same syntax.
+     The offset and label have the same syntax.
 
-     FIXME: POSIX 1003.1-2001 with XSI requires support for the
-     traditional syntax even if --traditional is not given.  */
+     If --traditional is not given, and if no modern options are
+     given, and if the offset begins with + or (if there are two
+     operands) a digit, accept only this form, as per POSIX:
+       od [file] [[+]offset[.][b]]
+  */
 
-  if (traditional)
+  if (!modern | traditional)
     {
-      uintmax_t offset;
+      uintmax_t o1;
+      uintmax_t o2;
 
-      if (n_files == 1)
+      switch (n_files)
        {
-         if (parse_old_offset (argv[optind], &offset))
-           {
-             n_bytes_to_skip = offset;
-             --n_files;
-             ++argv;
-           }
-       }
-      else if (n_files == 2)
-       {
-         uintmax_t o1, o2;
-         if (parse_old_offset (argv[optind], &o1)
-             && parse_old_offset (argv[optind + 1], &o2))
+       case 1:
+         if ((traditional || argv[optind][0] == '+')
+             && parse_old_offset (argv[optind], &o1))
            {
              n_bytes_to_skip = o1;
-             flag_pseudo_start = true;
-             pseudo_start = o2;
-             argv += 2;
-             n_files -= 2;
-           }
-         else if (parse_old_offset (argv[optind + 1], &o2))
-           {
-             n_bytes_to_skip = o2;
              --n_files;
-             argv[optind + 1] = argv[optind];
              ++argv;
            }
-         else
+         break;
+
+       case 2:
+         if ((traditional || argv[optind + 1][0] == '+'
+              || ISDIGIT (argv[optind + 1][0]))
+             && parse_old_offset (argv[optind + 1], &o2))
            {
-             error (0, 0,
-                    _("invalid second operand in compatibility mode `%s'"),
-                    argv[optind + 1]);
-             usage (EXIT_FAILURE);
+             if (traditional && parse_old_offset (argv[optind], &o1))
+               {
+                 n_bytes_to_skip = o1;
+                 flag_pseudo_start = true;
+                 pseudo_start = o2;
+                 argv += 2;
+                 n_files -= 2;
+               }
+             else
+               {
+                 n_bytes_to_skip = o2;
+                 --n_files;
+                 argv[optind + 1] = argv[optind];
+                 ++argv;
+               }
            }
-       }
-      else if (n_files == 3)
-       {
-         uintmax_t o1, o2;
-         if (parse_old_offset (argv[optind + 1], &o1)
+         break;
+
+       case 3:
+         if (traditional
+             && parse_old_offset (argv[optind + 1], &o1)
              && parse_old_offset (argv[optind + 2], &o2))
            {
              n_bytes_to_skip = o1;
@@ -1819,32 +1826,28 @@ it must be one character from [doxn]"),
              argv += 2;
              n_files -= 2;
            }
-         else
-           {
-             error (0, 0,
-           _("in compatibility mode, the last two arguments must be offsets"));
-             usage (EXIT_FAILURE);
-           }
+         break;
        }
-      else if (n_files > 3)
+
+      if (traditional && 1 < n_files)
        {
-         error (0, 0, _("extra operand %s"), quote (argv[optind + 3]));
-         fprintf (stderr, "%s\n",
-                  _("Compatibility mode supports at most three operands."));
+         error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
+         error (0, 0, "%s\n",
+                _("Compatibility mode supports at most one file."));
          usage (EXIT_FAILURE);
        }
+    }
 
-      if (flag_pseudo_start)
+  if (flag_pseudo_start)
+    {
+      if (format_address == format_address_none)
        {
-         if (format_address == format_address_none)
-           {
-             address_base = 8;
-             address_pad_len = 7;
-             format_address = format_address_paren;
-           }
-         else
-           format_address = format_address_label;
+         address_base = 8;
+         address_pad_len = 7;
+         format_address = format_address_paren;
        }
+      else
+       format_address = format_address_label;
     }
 
   if (limit_bytes_to_format)
@@ -1855,16 +1858,7 @@ it must be one character from [doxn]"),
     }
 
   if (n_specs == 0)
-    {
-      if (! decode_format_string ("o2"))
-       {
-         /* This happens on Cray systems that don't have a 2-byte
-            integral type.  */
-         exit (EXIT_FAILURE);
-       }
-
-      n_specs = 1;
-    }
+    decode_format_string ("oS");
 
   if (n_files > 0)
     {