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/************************************************************************
*
* Purpose: To display a file in (mainframe) dump format as shown below.
*
* 20 2A 20 68 65 78 5F 63 68 61 72 28 63 68 61 72 * hex_char(char
* 20 2A 70 6F 73 69 74 69 6F 6E 2C 20 63 68 61 72 *position, char
* 20 63 29 0A 20 20 20 7B 0A 20 20 20 73 70 72 69 c). {. spri
* 6E 74 66 28 70 6F 73 69 74 69 6F 6E 2C 20 22 25 ntf(position, "%
* 30 32 58 20 22 2C 20 63 29 3B 20 0A 0A 09 09 09 02X ", c); .....
*
* Syntax: hexdump filename
*
* Method: The program fills a variable (line) with the data, when
* the variable is full - it is sent to STDOUT.
* Unprintable charcters are converted to '.' in the ASCII
* display on the right.
*
* Bugs: If the last line of the dump is full, the program will
* follow it with a blank line. Not exactly a serious bug
* but you are welcome to fix it.
*
* To do: o Highlight '0A' (end of line) - seems like a good idea.
* o Get it to read directories.
* o Remove the directory info from argv[0] (if present).
* o Add a column showing the byte offset.
*
* Author: M J Leslie
*
* Rev Date Comments
* --- --------- --------
* 1.0 08-Feb-94 Inital Release.
*
* 1.1 12-May-95 Original only worked for the hex range 00-7F
* This version supports 00-FF.
* Thanks to Emmanuel Guyot for the fix.
*
************************************************************************/
#include <stdio.h>
#define HEX_OFFSET 1
#define ASCII_OFFSET 51
#define NUM_CHARS 16
/************************************************************************/
void hexdump (char* prog_name, char * filename);
/* Clear the display line. */
void clear_line (char *line, int size);
/* Put a character (in hex format
* into the display line. */
char * hex_char (char *position, int c);
/* Put a character (in ASCII format
* into the display line. */
char * ascii_char (char *position, int c);
/************************************************************************/
main(int argc, char * argv[])
{
char *prog_name="hexdump";
if (argc != 2)
{
printf("\n\t%s syntax:\n\n", argv[0]);
printf("\t\t%s filename\n\n", argv[0]);
exit(0);
}
hexdump( argv[0], argv[1]);
}
/************************************************************************
*
* The program proper.
*
************************************************************************/
void hexdump(char* prog_name, char * filename)
{
int c=' '; /* Character read from the file */
char * hex_offset; /* Position of the next character
* in Hex */
char * ascii_offset; /* Position of the next character
* in ASCII. */
FILE *ptr; /* Pointer to the file. */
char line[81]; /* O/P line. */
/* Open the file */
ptr = fopen(filename,"r");
if ( ferror(ptr) )
{
printf("\n\t%s: Unable to open %s\n\n", prog_name, filename);
exit(0);
}
/* little heading. */
printf("\n\tHex dump of %s\n\n", filename);
/* Read one character at a time,
* checking for the End of File.
* EOF is defined in <stdio.h> */
while (c != EOF )
{
/* Prepare the variables. */
clear_line(line, sizeof line);
hex_offset = line+HEX_OFFSET;
ascii_offset = line+ASCII_OFFSET;
while ( ascii_offset < line+ASCII_OFFSET+NUM_CHARS
&&(c = fgetc(ptr)) != EOF )
{
/* Build the hex part of
* the line. */
hex_offset = hex_char(hex_offset, c);
/* Build the Ascii part of
* the line. */
ascii_offset = ascii_char(ascii_offset, c);
}
/* Display the current line */
printf("%s\n", line);
}
fclose(ptr); /* Close the file. */
}
/************************************************************************
*
* Clear the display line.
*
************************************************************************/
void clear_line(char *line, int size)
{
int count;
for (count=0; count < size; line[count]=' ', count++);
}
/************************************************************************
*
* Put a character into the display line and return the location
* of the next character.
*
************************************************************************/
char * ascii_char(char *position, int c)
{
/* If the character is NOT printable
* replace it with a '.' */
if (!isprint(c)) c='.';
sprintf(position, "%c", c); /* Put the character to the line
* so it can be displayed later */
/* Return the position of the next
* ASCII character. */
return(++position);
}
/************************************************************************
*
* Put the hex value of a character into the display line and
* return the location of the next hex character.
*
************************************************************************/
char * hex_char(char *position, int c)
{
int offset=3;
/* Format and place the character into
* the display line.
* (unsigned char) required for correct
* O/P. */
sprintf(position, "%02X ", (unsigned char) c);
*(position+offset)=' '; /* Remove the '/0' created by 'sprint' */
return (position+offset);
}
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