Shell Programming and Scripting

   a6 82 (+31742 bytes)
   a6 00 12 00 (+31740 bytes)
   00 00 (00 31742 times)
   a6 00 12 34 (+31740 bytes)
   00 00 (00 31742 times)
   00 00 (00 31742 times)
   00 00 00 00 00 00

   a6 82 (+31742 bytes)
   a6 00 12 00 (+31740 bytes)
   a6 00 12 34 (+31740 bytes)

egrep -v -f Zeros_File Main_File

od -tu1 -An -w1 your_binary_file
 166
 130
 172
  87
  98
 228
  58
 100
 145
  40
...

$ printf "abc\000\000\000de\000" >file1

$ dd if=file1 of=file2 cbs=3 conv=unblock
0+1 records in
0+1 records out
12 bytes (12 B) copied, 0 s, Infinity B/s

$ od -hc file1; od -hc file2
0000000    6261    0063    0000    6564    0000
          a   b   c  \0  \0  \0   d   e  \0
0000011
0000000    6261    0a63    0000    0a00    6564    0a00
          a   b   c  \n  \0  \0  \0  \n   d   e  \0  \n
0000014

$ awk '/[^\000]/' file2 > file3

$ dd if=file3 of=file4 cbs=3 conv=block
0+1 records in
0+1 records out
6 bytes (6 B) copied, 0 s, Infinity B/s

$ od -hc file3; od -hc file4
0000000    6261    0a63    6564    0a00
          a   b   c  \n   d   e  \0  \n
0000010
0000000    6261    6463    0065
          a   b   c   d   e  \0
0000006

dd if=/dev/zero of=zero bs=31744 count=1

while dd count=1 bs=31744 > test
do
        diff test zero > /dev/null || cat test
done < datain > dataout

rm -f test datafile

#include <unistd.h>
#include <string.h>

int main(void)
{
        char buf[31744], zero[31744];
        ssize_t bpos=0;

        memset(zero, 0, sizeof(zero));

        while(1)
        {      // Read in entire chunk
                bpos=0;
                while(bpos < 31744)
                {
                        ssize_t r=read(STDIN_FILENO, buf+bpos, 31744-bpos);
                        if(r <= 0) // End of file
                                return(0);

                        bpos += r;
                }

                // check if zero
                if(memcmp(zero, buf, 31744) == 0) continue;

                bpos=0;
                // write out entire chunk
                while(bpos < 31744)
                {
                        ssize_t w=write(STDOUT_FILENO, buf+bpos, 31744-bpos);
                        if(w <= 0)
                                return(1); // write error

                        bpos += w;
                }
        }
}