└─▪ sudo size=$(blockdev --getsize64 /dev/mmcblk0p1); dd of=file.img bs=1M count=0 seek=$((size/1024/1024)); losetup /dev/loop0 file.img; mkfs.ext4 /dev/loop0; dd if=/dev/loop0 of=/dev/sdb1 bs=1M
blockdev: cannot open /dev/mmcblk0p1: Permission denied
usage: sudo [-D level] -h | -K | -k | -V
usage: sudo -v [-AknS] [-D level] [-g groupname|#gid] [-p prompt] [-u user name|#uid]
usage: sudo -l[l] [-AknS] [-D level] [-g groupname|#gid] [-p prompt] [-U user name] [-u user name|#uid] [-g groupname|#gid] [command]
usage: sudo [-AbEHknPS] [-C fd] [-D level] [-g groupname|#gid] [-p prompt] [-u user name|#uid] [-g groupname|#gid] [VAR=value] [-i|-s] [<command>]
usage: sudo -e [-AknS] [-C fd] [-D level] [-g groupname|#gid] [-p prompt] [-u user name|#uid] file ...
0+0 records in
0+0 records out
0 bytes (0 B) copied, 9.949e-06 s, 0.0 kB/s
/dev/loop0: Permission denied
mke2fs 1.42 (29-Nov-2011)
mkfs.ext4: Permission denied while trying to determine filesystem size
dd: opening `/dev/loop0': Permission denied