extract ouput that counts strings starting with A in the dataset

MVRS has asked for the wisdom of the Perl Monks concerning the following question:

hi monks as am not regular to perl, unable to get the output here am sending the i need the ouput that counts the sequences ending with A in the file piRNA_Dataset

>1
AAAAAAAAACAAAAATATTTTT     
>2
AAAAAAAAACAAAAGAACGAAGAAGT     
>3
AAAAAAAAACAACCGAAAAATAGAAAC     
>4
AAAAAAAAACAAGAAGGACTAGACC     
>5
AAAAAAAAACAAGGACTGGT     
>6
AAAAAAAAACAAGGACTGGTT     
>7
AAAAAAAAACAAGGACTGGTTTATCAG     
>8
AAAAAAAAACAAGTTTCTCTGTGACT     
>9
AAAAAAAAACAATACTGTAGTAT     
>10
AAAAAAAAACAATCAGCAGA     
>11
AAAAAAAAACACAGACGTAGAAT     
>12
AAAAAAAAACACAGACGTAGAATTGT     
>13
AAAAAAAAACACGACCGTTCGCT     
>14
AAAAAAAAACACGACCGTTCGCTTTGA     
>15
AAAAAAAAACACGACTGTTCGCTTT     
>16
AAAAAAAAACACTATGAGCCAGAAC     
>17
AAAAAAAAACACTTGTCTAAGGATA     
>18
AAAAAAAAACAGAAACGAGGAAA     
>19
AAAAAAAAACAGGACCGTTCT     
>20
AAAAAAAAACAGGACCGTTCTC     
>21
AAAAAAAAACAGGACCGTTCTCTT     
>22
AAAAAAAAACAGGACCGTTCTCTTT     
>23
AAAAAAAAACAGGACCGTTCTCTTTGAA     
>24
AAAAAAAAACATACTGAAAAACAAC     
>25
AAAAAAAAACATACTGAAAAACAACT     
>26
AAAAAAAAACATGGTTGGTACT     
>27
AAAAAAAAACATGGTTGGTACTCGA     
>28
AAAAAAAAACCCCTAGGAACTGACAC     
>29
AAAAAAAAACCCGTAGAAATCCTCTC     
>30
AAAAAAAAACCCGTTGGAGC     
>31
AAAAAAAAACCGCCATTCCGATCTG     
>32
AAAAAAAAACGAAACCAGAAA     
>33
AAAAAAAAACGAAAGAAAGAAT     
>34
AAAAAAAAACGAAAGCTACGA     
>35
AAAAAAAAACGAATTCTGGA     
>36
AAAAAAAAACGAATTCTGGAC     
>37
AAAAAAAAACGAATTCTGGACC     
>38
AAAAAAAAACGAATTCTGGACCAT     
>39
AAAAAAAAACGAATTCTGGACCATAG     
>40
AAAAAAAAACGAATTCTGGACCATAGT     
>41
AAAAAAAAACGAATTCTGGAT     
>42
AAAAAAAAACGAATTCTGGATT     
>43
AAAAAAAAACGAATTCTGGATTGGT     
>44
AAAAAAAAACGAATTCTGGATTGGTT     
>45
AAAAAAAAACGAATTCTGGATTGGTTA     
>46
AAAAAAAAACGACTCTTCATT     
>47
AAAAAAAAACGACTGAGTAGTTTGAGG     
>48
AAAAAAAAACGACTGTTCGCTT     
>49
AAAAAAAAACGATCGTCTGT     
>50
AAAAAAAAACGATCGTCTGTGCAAG     
>51
AAAAAAAAACGATCGTCTGTGCAAGCA     
>52
AAAAAAAAACGATCGTTTG     
>53
AAAAAAAAACGATGAACACTGT     
>54
AAAAAAAAACGATGAACACTGTTT     
>55
AAAAAAAAACGATGAACACTGTTTT     
>56
AAAAAAAAACGATTTAAGAAC     
>57
AAAAAAAAACGCCAACTCTGGGGGGG     
>58
AAAAAAAAACGCTTTAGAACTGAT     
>59
AAAAAAAAACGGAGCTGGAC     
>60
AAAAAAAAACGGAGCTGGACAAGGC     
>61
AAAAAAAAACGGAGTAGCAGACGT     
>62
AAAAAAAAACGGTAGAAC     
>63
AAAAAAAAACGGTAGAACTTTAGC     
>64
AAAAAAAAACGGTAGAACTTTAGCT     
>65
AAAAAAAAACGGTAGAACTTTAGCTTA     
>66
AAAAAAAAACGGTGCTGAAATTGAAC     
>67
AAAAAAAAACGGTGCTGAAATTGAACA     
>68
AAAAAAAAACGTCGGAACAGC     
>69
AAAAAAAAACGTCGGAATAGCTTAAT     
>70
AAAAAAAAACTAACATCGGCCTGCAGA     
>71
AAAAAAAAACTATGAATTGCAAT     
>72
AAAAAAAAACTATGAATTGCAATT     
>73
AAAAAAAAACTATTCTACTGTAACTC     
>74
AAAAAAAAACTGAAACCGAAACC     
>75
AAAAAAAAACTGAAACTGAAC     
>76
AAAAAAAAACTGAAACTGAACAACT     
>77
AAAAAAAAACTGAAACTGAACAACTGAA     
>78
AAAAAAAAACTGAATCGG     
>79
AAAAAAAAACTGATCAACAGAGGCGGCA     
>80
AAAAAAAAACTGATGGACAAACGCA     
>81
AAAAAAAAACTGATTGT
[download]

piRNA dataset is like this

Comment on extract ouput that counts strings starting with A in the dataset Download Code

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Re: extract ouput that counts strings starting with A in the dataset by choroba (Cardinal) on Feb 28, 2012 at 13:57 UTC
`$output[0]` is the first element of the array `@output`. What you need there is the first character of `$line`, which is `substr($line, 0, 1) eq 'A'` [download] Also, there is a precedence problem on your `open` line. Use `or` instead of `\|\|`, otherwise your statement means `open DATA, ( "<piRNA_Dataset" \|\| die "..." )` [download] which will never die.	[reply] [d/l] [select]
Re^2: extract ouput that counts strings starting with A in the dataset by MVRS (Acolyte) on Feb 29, 2012 at 05:07 UTC
Thankyou very much choroba , similarly i also want end of the string , but these are of different length , can you suggest me in this	[reply]
Re^3: extract ouput that counts strings starting with A in the dataset by choroba (Cardinal) on Feb 29, 2012 at 15:58 UTC
The last character is `substr $line, -1` [download] If you do not `chomp` your input, though, this might return end-of-line.	[reply] [d/l] [select]
Re: extract ouput that counts strings starting with A in the dataset by JavaFan (Canon) on Feb 28, 2012 at 14:16 UTC
No need for Perl: `$ grep -c ^A piRNA_Dataset` [download]	[reply] [d/l]
Re: extract ouput that counts strings starting with A in the dataset by CountZero (Bishop) on Feb 28, 2012 at 21:21 UTC
If the "`>1`" etc. are actually part of each line in your file, then you will need a regex to check the lines. `$line =~ m/>\d+\s+A/` will do that. CountZero A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James My blog: Imperial Deltronics	[reply] [d/l] [select]