Mail Archives: cygwin/2005/03/07/17:00:32
I was lamenting the lack of the simple "hexdump" facility
I have on linux. I figured -- how difficult would it be
to port that.
Well...not too, turns out, though, that it needs a type
quad_t and u_quad_t defined.
On linux, they are defined in /usr/include/sys/types.h
Should they be included in "cygwin's" types.h
as well or is there a better place for them?
They do work:
typedef long long int quad_t;
typedef long long unsigned u_quad_t;
Can I "motion" that they be included in cygwin's
/usr/include/sys/types.h?
They may not be the native machine's word size, but they
appear to be required for some of the linux utils to compile
correctly...
BTW, would there be any interest in including hexdump with the cyg utils?
I like the "-C" format alot -- lets me look at hex and ascii equivalents on
a file...
HEXDUMP(1) System General Commands Manual
HEXDUMP(1)
NAME
hexdump - ascii, decimal, hexadecimal, octal dump
SYNOPSIS
[-bcCdovx] [-e format_string] [-f format_file] [-n length] [-s skip]
file ...
DESCRIPTION
The hexdump utility is a filter which displays the specified files, or
the standard input, if no files are specified, in a user specified for
mat.
The options are as follows:
-b One-byte octal display. Display the input offset in
hexadec
imal, followed by sixteen space-separated, three column,
zero-filled, bytes of input data, in octal, per line.
-c One-byte character display. Display the input offset
in hex
adecimal, followed by sixteen space-separated, three
column,
space-filled, characters of input data per line.
-C Canonical hex+ASCII display. Display the input offset in
hexadecimal, followed by sixteen space-separated, two
column,
hexadecimal bytes, followed by the same sixteen bytes
in %_p
format enclosed in ‘‘|'' characters.
-d Two-byte decimal display. Display the input offset in hex
adecimal, followed by eight space-separated, five column,
zero-filled, two-byte units of input data, in unsigned
deci
mal, per line.
-e format_string
Specify a format string to be used for displaying data.
-f format_file
Specify a file that contains one or more newline separated
format strings. Empty lines and lines whose first
non-blank
character is a hash mark (#) are ignored.
-n length Interpret only length bytes of input.
-o Two-byte octal display. Display the input offset in
hexadec
imal, followed by eight space-separated, six column, zero-
filled, two byte quantities of input data, in octal, per
line.
-s offset Skip offset bytes from the beginning of the input. By
default, offset is interpreted as a decimal number. With a
leading 0x or 0X, offset is interpreted as a
hexadecimal num
ber, otherwise, with a leading 0, offset is interpreted
as an
octal number. Appending the character b, k, or m to offset
causes it to be interpreted as a multiple of 512, 1024, or
1048576, respectively.
-v The -v option causes hexdump to display all input data.
Without the -v option, any number of groups of output
lines,
which would be identical to the immediately preceding group
of output lines (except for the input offsets), are
replaced
with a line comprised of a single asterisk.
-x Two-byte hexadecimal display. Display the input offset in
hexadecimal, followed by eight, space separated, four
column,
zero-filled, two-byte quantities of input data, in
hexadeci
mal, per line.
For each input file, hexdump sequentially copies the input to standard
output, transforming the data according to the format strings specified
by the -e and -f options, in the order that they were specified.
Formats
A format string contains any number of format units, separated by
whites
pace. A format unit contains up to three items: an iteration count, a
byte count, and a format.
The iteration count is an optional positive integer, which defaults to
one. Each format is applied iteration count times.
The byte count is an optional positive integer. If specified it
defines
the number of bytes to be interpreted by each iteration of the format.
If an iteration count and/or a byte count is specified, a single slash
must be placed after the iteration count and/or before the byte
count to
disambiguate them. Any whitespace before or after the slash is
ignored.
The format is required and must be surrounded by double quote (" ")
marks. It is interpreted as a fprintf-style format string (see
fprintf(3)), with the following exceptions:
· An asterisk (*) may not be used as a field width or
precision.
· A byte count or field precision is required for each
‘‘s'' con
version character (unlike the fprintf(3) default which prints
the entire string if the precision is unspecified).
· The conversion characters ‘‘h'', ‘‘l'', ‘‘n'', ‘‘p'' and
‘‘q''
are not supported.
· The single character escape sequences described in the C
stan
dard are supported:
NUL \0
<alert character> \a
<backspace> \b
<form-feed> \f
<newline> \n
<carriage return> \r
<tab> \t
<vertical tab> \v
Hexdump also supports the following additional conversion strings:
_a[dox] Display the input offset, cumulative across input files, of
the next byte to be displayed. The appended characters
d, o,
and x specify the display base as decimal, octal or
hexadeci
mal respectively.
_A[dox] Identical to the _a conversion string except that it is
only
performed once, when all of the input data has been pro
cessed.
_c Output characters in the default character set.
Nonprinting
characters are displayed in three character, zero-padded
octal, except for those representable by standard escape
notation (see above), which are displayed as two character
strings.
_p Output characters in the default character set.
Nonprinting
characters are displayed as a single “.”.
_u Output US ASCII characters, with the exception that control
characters are displayed using the following, lower-case,
names. Characters greater than 0xff, hexadecimal, are dis
played as hexadecimal strings.
000 nul 001 soh 002 stx 003 etx 004 eot 005 enq
006 ack 007 bel 008 bs 009 ht 00A lf 00B vt
00C ff 00D cr 00E so 00F si 010 dle 011 dc1
012 dc2 013 dc3 014 dc4 015 nak 016 syn 017 etb
018 can 019 em 01A sub 01B esc 01C fs 01D gs
01E rs 01F us 0FF del
The default and supported byte counts for the conversion characters are
as follows:
%_c, %_p, %_u, %c One byte counts only.
%d, %i, %o, %u, %X, %x Four byte default, one, two and four byte
counts supported.
%E, %e, %f, %G, %g Eight byte default, four byte counts sup
ported.
The amount of data interpreted by each format string is the sum of the
data required by each format unit, which is the iteration count
times the
byte count, or the iteration count times the number of bytes
required by
the format if the byte count is not specified.
The input is manipulated in ‘‘blocks'', where a block is defined as the
largest amount of data specified by any format string. Format strings
interpreting less than an input block's worth of data, whose last
format
unit both interprets some number of bytes and does not have a specified
iteration count, have the iteration count incremented until the entire
input block has been processed or there is not enough data remaining in
the block to satisfy the format string.
If, either as a result of user specification or hexdump modifying the
iteration count as described above, an iteration count is greater than
one, no trailing whitespace characters are output during the last
itera
tion.
It is an error to specify a byte count as well as multiple conversion
characters or strings unless all but one of the conversion
characters or
strings is _a or _A.
If, as a result of the specification of the -n option or end-of-file
being reached, input data only partially satisfies a format string, the
input block is zero-padded sufficiently to display all available data
(i.e. any format units overlapping the end of data will display
some num
ber of the zero bytes).
Further output by such format strings is replaced by an equivalent
number
of spaces. An equivalent number of spaces is defined as the number of
spaces output by an s conversion character with the same field
width and
precision as the original conversion character or conversion string but
with any “+”, “ ”, “#” conversion flag characters removed, and
referenc
ing a NULL string.
If no format strings are specified, the default display is
equivalent to
specifying the -x option.
hexdump exits 0 on success and >0 if an error occurred.
EXAMPLES
Display the input in perusal format:
"%06.6_ao " 12/1 "%3_u "
"\t\t" "%_p "
"\n"
Implement the -x option:
"%07.7_Ax\n"
"%07.7_ax " 8/2 "%04x " "\n"
STANDARDS
The hexdump utility is expected to be IEEE Std 1003.2 (“POSIX.2”)
compat
ible.
BSD April 18,
1994 BSD
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