This works: -------BEGIN CODE------- #!/usr/bin/perl use warnings; use strict;
$/ = '>'; while (<DATA>) { s/(.*?\n.*?)\n/$1/s; print; } __DATA__ > YNL331C CAATATGCGAGGGACCTACATGTTGA CATGACAATGAATTCTATTGAAAAAA > YKL071W ATAATTATTCCTGTTTCTTTAACCTG GTAAAAAAAAGTACAAACACTTAAGC -------END CODE------- Please check your data for the first line: my line: CAATATGCGAGGGACCTACATGTTGACATGACAATGAATTCTATTGAAAAAA your line: CAATATGCGAGGGACCTACATGTTGAGCATGACAATGAATTCTATTGAAAAA ^ An extra G has been inserted into your "output would be" line denoted by the ^ above and an A deleted from the end of the line. I think my line is correct but will not swear to it. :-) -ZO "Edward Wijaya" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hi groups, > > I have a file which contain many many of this line (Fasta Format): > > > YNL331C > CAATATGCGAGGGACCTACATGTTGA > CATGACAATGAATTCTATTGAAAAAA > > > YKL071W > ATAATTATTCCTGTTTCTTTAACCTG > GTAAAAAAAAGTACAAACACTTAAGC > > What I would like to do is to concatenate the line below > > into one single string. > Such as the output would be: > > CAATATGCGAGGGACCTACATGTTGAGCATGACAATGAATTCTATTGAAAAA > ATAATTATTCCTGTTTCTTTAACCTGGTAAAAAAAAGTACAAACACTTAAGC -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] <http://learn.perl.org/> <http://learn.perl.org/first-response>