Re^2: Offset Reading

OK, yes I understand your valid points. Here is a little history: when I originally asked you the question I was facing a problem on retrieving data from a large file whose record structure information was stored in an index file. At that time the structure of the index file was sequential that is the next record was always starting right after the end of the prior record, so no offset was actually involved. The code you supplied was perfectly doing the retrieval by sequentially picking up chunks from the big file. Now the structure of the big file has been changed by the vendor and there is extraneous data in between each record for which I have to make use of the offset information each time before I can get the record I am interested in. I understand your surprise and the disappointment for my ignorance, I can only say I wish I had more time to dedicate to the discovery of Perl abilities ..... Thanks for all you did

Comment on Re^2: Offset Reading - two files

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Re^3: Offset Reading - two files by BrowserUk (Patriarch) on Dec 14, 2012 at 14:50 UTC
Now the structure of the big file has been changed by the vendor and there is extraneous data in between each record for which I have to make use of the offset information each time before I can get the record I am interested in.... I wish I had more time to dedicate to the discovery of Perl abilities That change appears to have happened 20 months ago. How have you been handling the problem in the interim? Have you heard of seek? With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. RIP Neil Armstrong	[reply]
Re^4: Offset Reading - two files by gio001 (Acolyte) on Dec 14, 2012 at 15:04 UTC
Hello, I have tried this, with no success: `perl -sple"BEGIN{open BIG};($1,$2)=split;seek(BIG,$1,$2);read(BIG,$_,$2)" -- -BIG=bigfile.dat index.dat >outfile.dat` What I asked '20 months' ago was not related to the change that occurred recently. Thanks	[reply] [d/l]
Re^5: Offset Reading - two files by BrowserUk (Patriarch) on Dec 14, 2012 at 15:10 UTC
seek does not take a length (`$2` as its third parameter. If you changed that to: `perl -sple"BEGIN{open BIG};($1,$2)=split;seek(BIG,$1,$2);read(BIG,$_,0 +)" -- -BIG=bigfile.dat index.dat >outfile.dat` [download] It might work. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. RIP Neil Armstrong Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.	[reply] [d/l] [select]
Re^6: Offset Reading - two files by gio001 (Acolyte) on Dec 14, 2012 at 15:46 UTC
Re^7: Offset Reading - two files by BrowserUk (Patriarch) on Dec 14, 2012 at 16:04 UTC
Some notes below your chosen depth have not been shown here
Re^7: Offset Reading - two files by johngg (Canon) on Dec 14, 2012 at 16:11 UTC
Re^7: Offset Reading - two files by Anonymous Monk on Dec 14, 2012 at 16:04 UTC
Re^4: Offset Reading - two files by gio001 (Acolyte) on Dec 14, 2012 at 15:06 UTC
Hello, I know I should not be wasting your time, sorry. Goodbye	[reply]