HD(C) XENIX System V HD(C)
Name
hd - Displays files in hexadecimal format.
Syntax
hd [ -format ... ] [ -s offset ] [ -n count ] [ file ] ...
Description
The hd command displays the contents of files in
hexadecimal, octal, decimal, and character formats. Control
over the specification of ranges of characters is also
available. The default behavior is with the following flags
set: ``-abx -A''. This says that addresses (file offsets)
and bytes are printed in hexadecimal and that characters are
also printed. If no file argument is given, the standard
input is read.
Options include:
-s offset Specify the beginning offset in the file where
printing is to begin. If no `file' argument is
given, or if a seek fails because the input is a
pipe, `offset' bytes are read from the input and
discarded. Otherwise, a seek error will
terminate processing of the current file.
The offset can be given in decimal, hexadecimal
(preceded by `0x'), or octal (preceded by a
`0'). It is optionally followed by one of the
following multipliers: w, l, b, or k; for words
(2 bytes), long words (4 bytes), half kilobytes
(512 bytes), or kilobytes (1024 bytes). Note
that this is the one case where ``b'' does not
stand for bytes. Since specifying a hexadecimal
offset in blocks would result in an ambiguous
trailing `b', any offset and multiplier can be
separated by an asterisk (*). (The asterisk
might need to be enclosed in quotation marks to
protect it from the shell.)
-n count Specify the number of bytes to process. The
count is in the same format as offset, above.
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HD(C) XENIX System V HD(C)
Format Flags
Format flags can specify addresses, characters, bytes, words
(2 bytes) or longs (4 bytes) to be printed in hex, decimal,
or octal. Two special formats can also be indicated: text
or ascii. Format and base specifiers can be freely combined
and repeated as desired in order to specify different bases
(hexadecimal, decimal or octal) for different output formats
(addresses, characters, etc.). All format flags appearing
in a single argument are applied as appropriate to all other
flags in that argument.
acbwlA
Output format specifiers for addresses, characters,
bytes, words, longs and ascii respectively. Only one
base specifier will be used for addresses; the address
will appear on the first line of output that begins
each new offset in the input.
The character format prints printable characters
unchanged, special C escapes as defined in the
language, and the remaining values in the specified
base.
The ascii format prints all printable characters
unchanged, and all others as a period (.). This format
appears to the right of the first of other specified
output formats. A base specifier has no meaning with
the ascii format. If no other output format (other than
addresses) is given, bx is assumed. If no base
specifier is given, all of xdo are used.
xdo Output base specifiers for hexadecimal, decimal and
octal. If no format specifier is given, all of acbwl
are used.
t Print a text file, each line preceded by the address in
the file. Normally, lines should be terminated by a \n
character; but long lines will be broken up. Control
characters in the range 0x00 to 0x1f are printed as
`^@' to `^_'. Bytes with the high bit set are preceded
by a tilde (~) and printed as if the high bit were not
set. The special characters (^, ~, \) are preceded by a
backslash (\) to escape their special meaning. As
special cases, two values are represented numerically
as `\177' and `\377'. This flag will override all
output format specifiers except addresses.
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