sudo e4defrag -c /path/to/myfiles

$ sudo e4defrag -c iso/
<Fragmented files>                             now/best       size/ext
1. /home/gerlos/iso/debian-live-7.5.0-i386-rescue.iso
                                                 7/1         111177 KB
2. /home/gerlos/iso/systemrescuecd-x86-4.4.1.iso
                                                 4/1         100897 KB
3. /home/gerlos/iso/debian-live-7.5.0-amd64-rescue.iso
                                                 6/1         116053 KB
4. /home/gerlos/iso/ubuntu-14.04.2-server-amd64.iso
                                                 8/1          76160 KB
5. /home/gerlos/iso/ubuntu-14.10-desktop-amd64.iso
                                                15/1          75712 KB

 Total/best extents             40/5
 Average size per extent            90577 KB
 Fragmentation score                0
 [0-30 no problem: 31-55 a little bit fragmented: 56- needs defrag]
 This directory (iso/) does not need defragmentation.
 Done.

e4defrag /path/to/myfiles

sudo e4defrag -c /dev/sda1

e4defrag -vc /path #verbose output with count