size_dir=$(stat -c %s $1) #$1 has the directory name (e.g. /root/kamal)

size_dir=$(/usr/bin/stat -c %s $1) #$1 has the directory name (e.g. /root/kamal)

# size=`php5 -r '$a=stat("file");echo $a[7];'`
# echo $size
123

perl -le 'print ((stat(shift))[7])' file

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

int main(int argc, char *argv[])
{
    struct stat filestats;
    stat(argv[1],&filestats);
   /*now  print to print whaever you want
      for example, 
      printf("%d\n",filestats.st_mtim.tv_sec);
   */
}