Hi! Thanks everyone for the help, I know I did a lot of stupid errors, but I just started with perl. I tried to run the script you suggested me, but it wasn't exactly what I need to do. I need to copy in the stdout only the number after the >, without the following lines. These are few lines of my input file: 
> 0 
CATCAAAATAATCATGTATTGGTAAAAGTTTAGTAAAAATACTAAAACTATTGACAATTCAAACTAATAC
+TTGTATAATGGAAGCGTATTCAAAAAATAAACAGGAGGTTCTCATAATGAGAAAATCTAACGTTCAGAT
+GAAGTCTCGTCTATCCTATGCAGCGGGTGCTTTTGGTAACGACGTCTTCTATGCAACGTTGTCAACATA
+CTTTATT
> 1 
CATCAAAATAATCATGTATTAGTAAAAGTTTAGTAAAAAATACTAAAACTATTGACAATTCAAACTAATA
+CTTGTATAATGGAAGCGTATTCAAAAAATAACAGGAGGTTCTCATAATGAGAAAATCTAACGTTCAGAT
+GAAGTCTCGTCTATCCTATGCAGCGGGTGCTTTTGGTAACGACGTCTACTATGCAACGTTGTCAACATA
+CTTTATT
> 10 
CATCAAGATAACCATGTATTAGTAAAATTTTAGTAAAAAACACTGAAATTATTGACTGCATAAACCAATT
+TTCATATAATGTAAACGTATTCAAATAATAGGAGGTTTCCGAAATGGAAAAATCTAAAGGTCAGATGAA
+GTCTCGTTTATCCTACGCAGCTGGTGCTTTTGATAACGACGTCTTCTATGCAACCTTGTCAACATTACT
+TTATC
> 100 
CATCAAAATAATCATGTATTAGTAAAAGTTTAGTAAAAATACTAAAACTATTGACAATTCAAACTAATAC
+TTGTATAATGGAAGCGTATTCAAAAAATGACAGGAGGTTCTCATAATGAGAAAATCTAACGTTCAGATG
+AAGTCTCGTCTATCCTATGCAGCGGGTGCTTTTGGTAACGACGTCTTCTATGCAACGTTGTCAACATAC
+TTTATT
...

[download]
I want to copy only the numers.... Running the sipt you suggested, I obtained this: 
> 
0 
CATCAAAATAATCATGTATTGGTAAAAGTTTAGTAAAAATACTAAAACTATTGACAATTCAAACTAATAC
+TTGTATAATGGAAGCGTATTCAAAAAATAAACAGGAGGTTCTCATAATGAGAAAATCTAACGTTCAGAT
+GAAGTCTCGTCTATCCTATGCAGCGGGTGCTTTTGGTAACGACGTCTTCTATGCAACGTTGTCAACATA
+CTTTATT 
> 
1 
CATCAAAATAATCATGTATTAGTAAAAGTTTAGTAAAAAATACTAAAACTATTGACAATTCAAACTAATA
+CTTGTATAATGGAAGCGTATTCAAAAAATAACAGGAGGTTCTCATAATGAGAAAATCTAACGTTCAGAT
+GAAGTCTCGTCTATCCTATGCAGCGGGTGCTTTTGGTAACGACGTCTACTATGCAACGTTGTCAACATA
+CTTTATT

[download]
How can I modify it? Man thanks for your help!! Francesca

In reply to Re^2: writing array element to a file by francesca1987
in thread writing array element to a file by francesca1987

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.