Thread: Display a 8 digit hex offset 0x?

> if(argc <3)
You've used argv[] twice before checking whether they exist.

> for(c ==0x200);//**This is where I try to get the 8 digit 0x hex offset**
Well you need to read up on the fact that the basic syntax is
for ( initial ; comparison ; step )

Also, the ; at the end means you wrote

Code:

for ( )
{
  // do nothing
}
{
    fprintf(stdout,"%04x", c);
}

Code:

#include<stdio.h>
#include<stdlib.h>
#include<sys/ioctl.h>




int main(int argc,char** argv)
{
    struct winsize terminal;
    FILE* fp;
    int a, c, column, row, lines;


    ioctl(0, TIOCGWINSZ,&terminal, argv[2]);


    fp = fopen(argv[1],"r");//set open for argv[1] and set it to read mode
    column = terminal.ws_col;
    row = terminal.ws_row;
    lines = atoi(argv[2]);


    // printf("Rows are: %d\n", row);
    // printf("Columns are: %d\n", column);


    if(argc <3)//Argument checking, at least three to run
    {
        printf("You need atleast 3 arguments to run!\n");
        exit(1);
    }


    if(fp == NULL)
    {
        fprintf(stderr,"Error opening '%s'.\n", argv[1]);//if not file is specified then close program and give an error
        exit(1);
    }
    c = fgetc(fp);//set c to fgetc


    if(column <80|| row <20)//if temrinal window is less than 80x20, display an error and exit
    {
        printf("Terminal window must be at least 80x20!\n");//display error and close program if column criteria isn't met
        exit(1);
    }


    /*
    while(!feof(fp))                                   //if file is entered, display a test message (this is where later on I will show hex value)


    {
        printf("Good Job! You picked a file to manipulate!!\n");
        exit(1);
     }
     */
    if(lines ==0)//if 0 is entered for argv[2], display all the lines, 512 byte file
    {
        printf("------------------------------------------------------------------------------\n");//**this is where I try to display character/hex banner**
        printf("offset      0  1  2  3   4  5  6  7   8  9  a  b   c  d  e  f  ascii\n");
        printf("-------------------------------------------------------------------------------\n");
        printf("0x%08x\n" , c);

    }
    elseif(lines ==20)
    {
        printf("This will print out 20 lines\n");
    }
    elseif(lines ==30)
    {
        printf("This will print out 30 lines\n");
    }
    else
    {
        printf("Please Enter a Valid Number!\n");
    }


    fclose(fp);//close fp


    return0;
}

This is my current code with an output of

Code:

~//cbf0$ ./cbf0 win7.mbr 0
------------------------------------------------------------------------------
offset      0  1  2  3   4  5  6  7   8  9  a  b   c  d  e  f  ascii
-------------------------------------------------------------------------------
0x00000033

and my desired output would be:

Code:

l~/cbf0$ ./cbf0 win7.mbr 0
------------------------------------------------------------------------------
offset      0  1  2  3   4  5  6  7   8  9  a  b   c  d  e  f  ascii
-------------------------------------------------------------------------------
0x00000000
0x00000010
0x00000020
0x00000030
0x00000040
0x00000050
0x00000060
0x00000070
0x00000080
0x00000090
0x000000a0
"and so on.."

Well you need to put fgetc() inside a loop which does the following
- reads a character
- formats it as 2 hex digits
- generates an ascii representation (if the char is printable).
- prints an address after reading 16 characters

Plus the other issues I mentioned 2 days ago.


Start with something simple like

Code:

int addr = 0, numchars = 0;
while ( (ch=fgetc(fp)) != EOF ) {
  unsigned char c = (unsigned char)ch;
  if ( (numchars++ % 16 ) == 0 ) {
    printf("\n%08x: ", addr);
    addr += 16;
  }
  printf("%02x ", c );
}