Dear all,

I have several FASTA nucleotide file, containing millions identifiers and their sequence. Among them, there are some identifier like this, ">AT1G01340|AT1G01340.2 Sequence unavailable". Would you please let me know how I can remove them? looking forward to hearing your helpful commands. thanks
I have modified the perl script which should work for your cause

```
#!/usr/bin/perl
use strict;
use warnings;

$/="\n>";

while (<>) {
 s/>//g;
  my ($id, $seq) = split (/\n/, $_);
  print ">$_" if ((length $seq) > 10 && $seq !~ "Sequence unavailable");
}
```

hth