filter and stats using seqkit

$ cat hairpin.fa | seqkit seq | seqkit stats
file  format  type  num_seqs    sum_len  min_len  avg_len  max_len
-     FASTA   RNA     28,645  2,949,871       39      103    2,354

$ cat hairpin.fa | seqkit seq -m 100 | seqkit stats
file  format  type  num_seqs    sum_len  min_len  avg_len  max_len
-     FASTA   RNA     10,975  1,565,486      100    142.6    2,354

$ cat hairpin.fa | seqkit seq -m 100 -M 1000 | seqkit stats
file  format  type  num_seqs    sum_len  min_len  avg_len  max_len
-     FASTA   RNA     10,972  1,560,270      100    142.2      938