/* issparse -- checks for partly populated files and prints their name

  Compile:
  cc -Wall --pedantic  issparse.c   -o issparse
 
  Create a sparsefile:
  dd if=/dev/zero of=sparsefile count=12 obs=1 seek=100k

  Check for sparsefiles:
  $ issparse sparsefile 
  sparsefile
  $ echo $?
  0
  $ issparse /etc/profile
  $ echo $?                
  1
  $ issparse sparsefile /etc/profile && echo sparse!
  sparsefile
  sparse!
*/

#include <libgen.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#define PROGNAME "issparse"

#ifndef PROGNAME
#define PROGNAME __FILE__
#endif

int main(int argc, char *argv[])
{
  struct stat filestats;
  int t=1;
  int retvalue=1;

  if(!(argc>1) || argv[1][0]=='-')
  {
    puts( PROGNAME" / "__DATE__" "__TIME__);
    puts( "Usage: " PROGNAME " [FILE] ... ");
    return(-1);
  }

  while(t<argc)
  {
    if(stat(argv[t], &filestats)==0)
    {
      if(filestats.st_blksize*filestats.st_blocks<filestats.st_size)
      {
        retvalue=0;
        puts(argv[t]);
      }
    }
    else
    {
      puts(PROGNAME": file not found.");
      puts(argv[t]);
      return(-1);
    }
    t++;
  }

  return(retvalue);
}