Sorry but Im getting this error (even though I have tried download link under your code) :- 
Use of uninitialized value in join or string at check_22nov_metabolite
+_pred_2.pl line 74, <DATA> line 6.
M7:   M7<-Q, P.
Use of uninitialized value in join or string at check_22nov_metabolite
+_pred_2.pl line 74, <DATA> line 6.
M54:  M54<-M7<-Q, Pl.P.
Use of uninitialized value in join or string at check_22nov_metabolite
+_pred_2.pl line 74, <DATA> line 6.
M194: M194<-M54<-M7<-Q, E.Pl.P.
Use of uninitialized value in join or string at check_22nov_metabolite
+_pred_2.pl line 74, <DATA> line 6.
M206: M206<-M54<-M7<-Q, E.Pl.P.
Use of uninitialized value in join or string at check_22nov_metabolite
+_pred_2.pl line 74, <DATA> line 6.
M213: M213<-M54<-M7<-Q, E.Pl.P.

[download]

In reply to Re^2: find shortest path for each query from a CSV file by zing
in thread find shortest path for each query from a CSV file by zing

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