diff --git a/src/rmi_splitter/rmi_splitter.py b/src/rmi_splitter/rmi_splitter.py
index d31683511405bd33d381eb86d251294d545b2f0e..9f0a48d477d1e7119e600cc6dc13bb34b8fa0121 100644
--- a/src/rmi_splitter/rmi_splitter.py
+++ b/src/rmi_splitter/rmi_splitter.py
@@ -14,7 +14,7 @@ import getopt
 from Bio import SeqIO
 from Bio.SeqRecord import SeqRecord
 import yaml  # pip install pyyaml
-import suffix_tree
+from . import suffix_tree
 from gzip import open as gzopen
 
 
@@ -607,7 +607,7 @@ def parse_ntuples_fastq(ffastqs,
             sequences_number += 1
             line_number = -1
         line_number += 1
-    print("number of processed sequences: " + str(sequences_number))
+    print("number of processed sequences: " + str(sequences_number-1))
 
 
 def out_files(fastqs, condition, results_path):
@@ -740,13 +740,18 @@ def usage():
     """
     Print command line help
     """
-    print('usage : python rmi_splitter.py -f <inputfile1[,inputfile2...,\
-inputfileN]> -o <outputfolder> -c <configfile> [OPTIONS]\n\n')
-    print("options : \n\
+    print('usage : rmi_splitter -f <inputfile1[,inputfile2...,inputfileN]> \
+-o <outputfolder> -c <configfile> [OPTIONS]\n')
+    print("mandatory parameters : \n\
+        -f, --fastqs    list of fastq files separated by a comma without \
+whitespaces \n\
+        -o, --ofolder   path to the output folder. Need to be empty or if not\n\
+                        exists, rmi_splitter creates it\n\
+        -c, --config    path to the config file in yaml format\n\noptions : \n\
         -h, --help      print this message\n\
         -v, --verbose   only usefull for debugging\n\
-        -m, --mismatch  number of mismatch allowed. By default, n-1 mismatches\n\
-                        are allowed (n = barcode length) \n\
+        -m, --mismatch  mismatches allowed per adaptor. By default, n-1 \n\
+                        mismatches are allowed (n = adaptor length) \n\
         -n, --ntuple    number of matched files. If not set, rmi_splitter try\n\
                         to guess it from the config file")
 
@@ -765,6 +770,7 @@ def check_options(argv):
                                                       "config=",
                                                       "verbose",
                                                       "mismatch=",
+                                                      "ofolder="
                                                       "ntuple="])
 
     except getopt.GetoptError:
@@ -858,6 +864,9 @@ def main(argv=None):
     """
     if argv is None:
         argv = sys.argv[1:]
+    if len(argv) == 0:
+        usage()
+        exit(0)
 
     """
     check and grep optionscreate_barcode_dict