With this line:
(echo o; echo n; echo p; echo 1; echo ; echo +24G; echo a; echo t; echo 7; echo w) | fdisk /dev/sda
I can create a new active primary partition for NTFS, 24 Giga large. The syntax is ugly but effective.
How can I do the same with parted or sfdisk?
This is easy using parted. The -s option is used for scripting. The following produces the same results as your fdisk line:
parted -s /dev/sda mkpart primary NTFS 1 24G
mklabel msdos before the mkpart (what used to be echo o in the fdisk command above).
fdisk ?
parted does not support the +24G syntax. Closest you can get is using shell arithmetic instead so you can use something along the lines of parted ... $start $(($start+$size)).
With sfdisk:
sudo sfdisk --label dos /dev/sda <<EOF
device: /dev/sda
unit: sectors
sector-size: 512
size= $((24 * 2097152)), type=7, bootable
EOF
Note that sfdisk deals with starting position and alignment of partitions automatically if the values are not specified. The header might not even be necessary but I usually include those values just to be sure.
