NAME

hd − display files in hexadecimal format

SYNOPSIS

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 may be given in decimal, hexadecimal (preceded by ‘Ox’), 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), blocks (512 bytes), or K bytes (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 may be separated by an asterisk (∗). 

-n count Specify the number of bytes to process.  The count is in the same ­format as offset, above. 

Format Flags

Format flags may specify addresses, characters, bytes, words (2 bytes), or longs (4 bytes) to be printed in hexadecimal, decimal, or octal.  Two special formats may also be indicated: test or ASCII.  Format and base specifiers amy 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 address, 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 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 test 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 rpinted 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. 

  —  Application Compatibility Package