패킷덤프 C 코드

int main(int argc, char *argv)
{
	char *buffer = "In the UNIX environment a thread: \n" \
		"Exists within a process and uses the process resources\n" \
		"Has its own independent flow of control as long as its parent process exists and the OS supports it\n" \
		"May share the process resources with other threads that act equally independently (and dependently)\n" \
		"Dies if the parent process dies - or something similar\n";

	packet_dump(buffer, strlen(buffer), 16);
}

$ ./packet_dump
[   0] 49 6e 20 74 68 65 20 55-4e 49 58 20 65 6e 76 69   In the UNIX envi
[   1] 72 6f 6e 6d 65 6e 74 20-61 20 74 68 72 65 61 64   ronment a thread
[   2] 3a 20 0d 0a 45 78 69 73-74 73 20 77 69 74 68 69   : ..Exists withi
[   3] 6e 20 61 20 70 72 6f 63-65 73 73 20 61 6e 64 20   n a process and
[   4] 75 73 65 73 20 74 68 65-20 70 72 6f 63 65 73 73   uses the process
[   5] 20 72 65 73 6f 75 72 63-65 73 0d 0a 48 61 73 20    resources..Has
[   6] 69 74 73 20 6f 77 6e 20-69 6e 64 65 70 65 6e 64   its own independ
[   7] 65 6e 74 20 66 6c 6f 77-20 6f 66 20 63 6f 6e 74   ent flow of cont
[   8] 72 6f 6c 20 61 73 20 6c-6f 6e 67 20 61 73 20 69   rol as long as i
[   9] 74 73 20 70 61 72 65 6e-74 20 70 72 6f 63 65 73   ts parent proces
[  10] 73 20 65 78 69 73 74 73-20 61 6e 64 20 74 68 65   s exists and the
[  11] 20 4f 53 20 73 75 70 70-6f 72 74 73 20 69 74 0d    OS supports it.
[  12] 0a 4d 61 79 20 73 68 61-72 65 20 74 68 65 20 70   .May share the p
[  13] 72 6f 63 65 73 73 20 72-65 73 6f 75 72 63 65 73   rocess resources
[  14] 20 77 69 74 68 20 6f 74-68 65 72 20 74 68 72 65    with other thre
[  15] 61 64 73 20 74 68 61 74-20 61 63 74 20 65 71 75   ads that act equ
[  16] 61 6c 6c 79 20 69 6e 64-65 70 65 6e 64 65 6e 74   ally independent
[  17] 6c 79 20 28 61 6e 64 20-64 65 70 65 6e 64 65 6e   ly (and dependen
[  18] 74 6c 79 29 0d 0a 44 69-65 73 20 69 66 20 74 68   tly)..Dies if th
[  19] 65 20 70 61 72 65 6e 74-20 70 72 6f 63 65 73 73   e parent process
[  20] 20 64 69 65 73 20 2d 20-6f 72 20 73 6f 6d 65 74    dies - or somet
[  21] 68 69 6e 67 20 73 69 6d-69 6c 61 72 0d 0a         hing similar..
$

#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

void packet_dump(char* buf, int size, int unit)
{
     char     tmp[150];
     char     msg[256];
     int      i, j, lno;

     j = 7;
     lno = 0;
     memset((tmp+0), 0x00, 150);
     
     for (i = 0; i < size; i++) {
          if((i%unit) == 0)
               memset((tmp+0), 0x20, ((unit*3)+unit+1+7+3));
          if(j == 7)
               sprintf((tmp+0), "[%4d] ", lno);
          sprintf((tmp+j), "%02x", (unsigned char)*(buf+i));
          tmp[j+2] = 0x20;
          if((unsigned char)*(buf+i) >= (unsigned char)0x20)
               tmp[(j/3)+(unit*3)+1+6] = *(buf+i);
          else
               tmp[(j/3)+(unit*3)+1+6] = '.';
          j += 3;
          if((i%unit) == (unit-1)) {
               printf("%s\n", (tmp+0));
               j = 7;
               ++lno;
          }
          else if((i%unit) == ((unit/2)-1))
               tmp[j-1] = '-';
     }
     
     if ((i % unit) != 0) {
	 printf("%s\n", (tmp+0));
     }
}