**Tool used:** [seqkit][1]

Dummy fasta file (fasta.fa):

    >test1
    GCATCGATCAGCTACGATCATCACTA
    GNNNNNNTACATCAGCACTACATCACTNNNNN
    >test2
    GTACGCTACGANNNGCTACGACTACGATATATATATATATATATATATATATATATATATATAT
    GCTACGATCACNTACATCGACTA
    >test3
    GTGTGCTACATCATCACTACGTACTACAT
    >test4
    AA

**Command:** 

    ./seqkit stat fasta.fa

**Output:**

    file      format  type  num_seqs  sum_len  min_len  avg_len  max_len
    fasta.fa  FASTA   DNA          4      176        0       44       87

**Problem:**
**min_len** =0 (however, minimum length should be 2; sequence id "test4")

**Validation using seqkit:**

**Command:**

    ./seqkit fx2tab -l fasta.fa

**Output:**

    test1	GCATCGATCAGCTACGATCATCACTAGNNNNNNTACATCAGCACTACATCACTNNNNN		58
    test2	GTACGCTACGANNNGCTACGACTACGATATATATATATATATATATATATATATATATATATATGCTACGATCACNTACATCGACTA		87
    test3	GTGTGCTACATCATCACTACGTACTACAT		29
    test4	AA		2

**Notice: length of sequence test4 is "2"**

Is it a bug or I misunderstood something?

**PS: I am loving this tool (all thanks to [Wei Shen][2])and trying to exploit the utilities to make a new tool!**


  [1]: https://github.com/shenwei356/seqkit
  [2]: https://www.biostars.org/u/4664/
For the data you posted I get the correct result using Version: 0.3.4.1

    file  format  type  num_seqs  sum_len  min_len  avg_len  max_len
    demo  FASTA   DNA          4      176        2       44       87