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• unable to access usb device.

  - by Tom

  Hi everyone, I'm reading my boot logs, at /var/log trying to understand why the boot process is taking so long. I found that the system can't access many usb devices, but can't understand why. Is there a way to stop Ubuntu from trying to access them? Here are the lines: /var/log# grep -r "usb_id" . ./boot.log:usb_id[716]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input7/mouse1' ./boot.log:usb_id[721]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input7/event7' ./boot.log:usb_id[725]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input7/event7' ./syslog:Jan 12 21:12:05 TomsterInc usb_id[955]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input16/event16' ./syslog:Jan 12 21:12:05 TomsterInc usb_id[956]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input16/mouse3' ./syslog:Jan 12 21:12:05 TomsterInc usb_id[963]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input16/event16' ./daemon.log:Jan 12 21:12:05 TomsterInc usb_id[955]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input16/event16' ./daemon.log:Jan 12 21:12:05 TomsterInc usb_id[956]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input16/mouse3' ./daemon.log:Jan 12 21:12:05 TomsterInc usb_id[963]: unable to access '/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/input/input16/event16' Any help will be greatly appreciated. Thanks in advance.

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• How to view status of software RAID 1 resynching?

  - by tputkonen

  I have two 500 GB disks and yesterday I mirrored first drive to the second one using software RAID 1. PC has now been on for 30 hours. Both disks say "Resynching", but there is no progress indicator. In addition, there is a small yellow exclamation mark on both disks. My questions are: How long could the synch take for 500 GB drive with about 150 GB of data? PC has 4 GBs of RAM and AMD dual core 4000+ Is there a way to monitor status of the synching? How can I check what the exclamation mark means?

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• Cannot Restore GRUB (Ubuntu 11.04 + Win 7)

  - by Benny

  I'm trying to fix GRUB on my PC, but I'm running into serious issues doing so. Any help would be greatly appreciated as I'm completely crippled right now. Here is the sequence of events for this PC: Installed Windows 7 Split full disk into two partitions (one for win7 and one for multimedia) Long time passed Split one of the partitions into two again Installed Ubuntu 11.04 on new partition A little time passed Windows 7 acting up, reinstall Ubuntu GRUB gone Tried restoring GRUB by mounting and grub-install from live USB Tried switching to a live CD instead of USB (thinking it might be the drive) Now I don't see GRUB and I'm getting "input/output" errors An example i/o error: ubuntu@ubuntu:~$ sudo fdisk -l Disk /dev/sda: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xbe86aff6 Device Boot Start End Blocks Id System /dev/sda1 * 1 48727 391393280 7 HPFS/NTFS /dev/sda2 48727 77063 227612647+ 7 HPFS/NTFS /dev/sda3 77063 91202 113566721 5 Extended /dev/sda5 77063 90622 108908544 83 Linux /dev/sda6 90622 91202 4657152 82 Linux swap / Solaris ubuntu@ubuntu:~$ sudo mount /dev/sda5 /mnt ubuntu@ubuntu:~$ sudo grub-install --root-directory=/mnt /dev/sda mkdir: cannot create directory `/mnt/boot': Input/output error ubuntu@ubuntu:~$ cd /mnt ubuntu@ubuntu:/mnt$ ls ls: cannot access etc: Input/output error

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• How to use correctly the comments in C/++

  - by Lucio

  I'm learning to program in C and in my stage, the best form to use correctly the comments is writing good comments from the beginning. As the comments are not just for that one understands better the code but others too, I want to know the views of all of you to reach a consensus. So what I want is that the most experienced users edit the following code as you please. (If it's unnecessary, delete it; If it's wrong, correct it; If needed, add more) Thus there'll be multiple answers with different syntax and the responses with the most votes will be taken as referring when commenting. The code to copy, paste and edit to your pleasure is: (And I remark again, just import the comments, not the code) /* This programs find 1 number in 1 file. The file is binary type and has integers in series. The number is integer type and it's entered from the keyboard. When finished the program, a poster will show the results: Saying if the number is in the file or not. */ #include <stdio.h> //FUNCTION 1 //Open file 'path' and closes it. void openf(char path[]) { int num; //Read from Keyboard a Number and it save it into 'num' var printf("Ready for read number.\n\nNumber --> "); fflush(stdin); scanf("%d",&num); //Open file 'path' in READ mode FILE *fvar; fvar=fopen(path,"rb"); //IF error happens when open file, exit of function if (fvar==NULL) { printf("ERROR while open file %s in read mode.",path); exit(1); } /*Verify the result of 'funct' function IF TRUE, 'num' it's in the file*/ if (funct(path,fvar,num)) printf("The number %d it is in the file %s.",num,path); else printf("The number %d it is not in the file %s.",num,path); fclose(fvar); } /*FUNCTION 2 It is a recursive function. Reads number by number until the file is empty or the number is found. Parameters received: 'path' -> Directory file 'fvar' -> Pointer file 'num' -> Number to compare */ int funct(char path[],FILE *fvar,int num) { int compare; //FALSE condition when the pointer reaches the end if (fread(&compare,sizeof(int),1,fvar)>0) /*TRUE condition when the number readed is iqual that 'num' ELSE will go to the function itself*/ if (compare!=num) funct(path,fvar,num); else return 1; else return 0; } int main(int argc, char **argv) { char path[30]="file.bin"; //Direction of the file to process openf(path); //Function with algorithm return 0; }

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• Can anyone recommend an AI sandbox?

  - by user19433

  I'm passionate person, who has been around AI from a long time [1] but never going in deep enough. Now it's time! I've been really looking for some way to concentrate on AI coding but couldn't succeeded to find an AI environment I can focus on. I just want to use an AI sandbox environment which would let me have tools like: visibility information character controller able to easily define a level, with obstacles of course physics collider management triggers management don't need to be a shiny, eye candy graphical render : this is about pathfinding, tactical reasoning, etc.. I have tried : Unreal Dev Kit : while the new release announce is about C++ coding, this is about external tools and will be released in 2013 Cry Engine : really interesting as AI is presents here but coding with it appears to be an hell: did I got it wrong ? Half Life source, C4, Torque, Dx Studio : either quite old, not very useful or costly these imply to dig in documentation (when provided) to code everything, graphics included. Unity 3D : the most promising platform. While you also need to create your own environment, there are lot of examples. The disadvantage is, in addition to spend time to have this env. working, is the languages choice : C#, Javascript or Boo. C# is not that hard, but this implies you'll allways have to convert papers (I love those from Lars Linden) books codes, or anything you can have in Aigamedev are most often in C++. This is extra work. I've look at "Simple Path", the very good Arong Greenberg work but no source provided and AngryAnt work. AI Sandbox : this seems to be exactly what as AI coder I want to use. I saw some preview but from 2009 we still don't know what it will be about precisely, will it be opensource or free (I strongly doubt), will I be able to buy it? will it really provide me tools I need to focus on AI ? That being said, what is the best environment to be able to focus on AI coding only, is it even possible?

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• Returning Value of Radio Button Jquery [migrated]

  - by Jerry Walker

  I am trying to figure out why, when I run this code, I am getting undefined for my correct answers. $(document).ready (function () { // var answers = [["Fee","Fi","Fo"], ["La","Dee","Da"]], questions = ["Fee-ing?", "La-ing?"], corAns = ["Fee", "La"]; var counter = 0; var $facts = $('#main_ .facts_div'), $question = $facts.find('.question'), $ul = $facts.find('ul'), $btn = $('.myBtn'); $btn.on('click', function() { if (counter < questions.length) { $question.text(questions[counter]); var ansstring = $.map(answers[counter], function(value) { return '<li><input type="radio" name="ans" value="0"/>' + value + '</li>'}).join(''); $ul.html(ansstring); var currentAnswers = $('input[name="ans"]:checked').map(function() { return this.val(); }).get(); var correct = 0; if (currentAnswers[counter]==corAns[counter]) { correct++; } } else { $facts.text('You are done with the quiz ' + correct); $(this).hide(); } counter++; }); // }); It is quite long and I'm sorry about that, but I don't really know how tostrip it down. I also realize this isn't the most elegant way to do this, but I just want to know why I can't seem to get my radio values. I will add the markup as well if anyone wants.

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• TCO Comparison: Oracle Exadata vs IBM P-Series

  - by Javier Puerta

  Cost Comparison for Business Decision-makersOracle Exadata Database Machine vs. IBM Power SystemsHow to Weigh a Purchase DecisionOctober 2012 Download full report here In this research-based  white paper conducted at the request of Oracle, The FactPoint Group compares the cost of ownership of the Oracle Exadata engineered system to a traditional build-your-own (BYO) solution, in this case an IBM Power 770 (P770) with SAN storage.  The IBM P770 was chosen given it is IBM’s current most popular model, based on FactPoint primary and secondary research and IBM claims, and because at least one of the interviewed customers had specifically migrated from a P770 to Exadata, affording us a more specific data point for comparison. This research found that Oracle Exadata: Can be deployed more quickly and easily requiring 59% fewer man-hours than a traditional IBM Power Systems solution. Delivers dramatically higher performance typically up to 12X improvement, as described by customers, over their prior solution.  Requires 40% fewer systems administrator hours to maintain and operate annually, including quicker support calls because of less finger-pointing and faster service with a single vendor.  Will become even easier to operate over time as users become more proficient and organize around the benefits of integrated infrastructure. Supplies a highly available, highly scalable and robust solution that results in reserve capacity that make Exadata easier for IT to operate because IT administrators can manage proactively, not reactively.  Overall, Exadata operations and maintenance keep IT administrators from “living on the edge.”  And it’s pre-engineered for long-term growth. Finally, compared to IBM Power Systems hardware, Exadata is a bargain from a total cost of ownership perspective:  Over three years, the IBM hardware running Oracle Database cost 31% more in TCO than Exadata.

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• How to write constructors which might fail to properly instantiate an object

  - by whitman

  Sometimes you need to write a constructor which can fail. For instance, say I want to instantiate an object with a file path, something like obj = new Object("/home/user/foo_file") As long as the path points to an appropriate file everything's fine. But if the string is not a valid path things should break. But how? You could: 1. throw an exception 2. return null object (if your programming language allows constructors to return values) 3. return a valid object but with a flag indicating that its path wasn't set properly (ugh) 4. others? I assume that the "best practices" of various programming languages would implement this differently. For instance I think ObjC prefers (2). But (2) would be impossible to implement in C++ where constructors must have void as a return type. In that case I take it that (1) is used. In your programming language of choice can you show how you'd handle this problem and explain why?

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• Grep the whole body of a function

  - by dotancohen

  Supposing I know that someFile.php contains the definition for someFunction(). How would I go about displaying the whole body of the function in stdout? If I know that the body is 10 lines long then I would use cat someFile.php | grep -A 10 "function someFunction" [1] but in reality the function could be any arbitrary length. I figured that with sed I could use Vimesque commands such as /function someFunction<Return>/{<Return>% [2] but I can't figure out exactly how to format it. Ideally, the PHPDoc before the function would be output along with the function. Any help or links to the appropriate fine manual would be appreciated. Thanks! [1] I know that the cat is redundant, but I find this format easier to read. [2] Find the function definition, go to the opening brace, go to the close brace

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• How does the build quality of laptops compare?

  - by pgwillia

  I'm looking to replace my 5 year old laptop. I want my next laptop to endure at least this long. I typically have Thunderbird, Firefox, Eclipse Java IDE, Skype, a ssh session, and Apache Tomcat running. I'm currently running Karmic Ubuntu, but am agnostic about operating system and would move to Win 7 or OS X. I frequently travel with this computer. I also value battery longevity and power conservation (if possible). Above all I'm looking to minimize cost. I think the hardware that best meets my needs is an Intel i7 processor, 8 GB RAM, 100GB @7200 rpm or SSD hardrive, and about 15 inch monitor. These specs are met by most brands. Does anyone know specific pros/cons and build quality for Macbook Pro, Lenovo Thinkpad (W510 or T510), Sony's VPC-F1190, and ASUS G Series G73JH-X1 NoteBook? Are all i7 processors created equal? Do you have other suggestion that meet my needs?

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• Does RDNS for mail server have to match the mail server hostname exactly?

  - by threecheeseopera

  Typically when setting up a mail server, I create an rDNS record for the mail server IP to match the mail server hostname (ex: mail.example.com). Can I instead set the rDNS ptr to match the parent domain (e.g. example.com), if this server is being used for multiple purposes, and still send mail successfully (i.e. not be classified as spam b/c of mismatched rDNS)? Thanks! EDIT: The article at http://en.wikipedia.org/wiki/Forward_Confirmed_reverse_DNS seems to indicate that it might be more complicated than I had thought. For instance, 1) I did not know that you could have multiple PTR records for a given IP; 2) it appears that as long as each PTR record matches an A record, everything is good (basically nullifying my question). Would you agree?

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• Instructor Insight: Dealing with Columns in Oracle JD Edwards Enterprise One Tools Release 9.1

  - by Breanne Cooley

  Oracle JD Edwards Enterprise One Tools Release  9.1 has many new features that will help end users be more efficient in their daily jobs. For example, hiding grid columns is now as easy as a left-mouse click. In earlier releases, users could click on the ‘Customize Grid’ link but still had to do several more clicks to hide or show a column . The following example shows how easy this new feature is to use. First, right-mouse click on the column you want to hide; for example the ‘Long Address’ column. The column is now hidden. Second, right-mouse over on any of the columns to show the ‘Unhide’ option. After you select ‘Unhide’, the hidden column is shown. You can then select the column to show, or unhide, the column. This new feature and others are covered in the JD Edwards EnterpriseOne System Administration Rel 9.x course, which has been updated to reflect the new release. Hope to see you in class! -Randy Richeson, Senior Principal Instructor, Oracle University

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• How to go from Mainframe to the Cloud?

  - by Ruma Sanyal

  Running applications on IBM mainframes is expensive, complex, and hinders IT responsiveness. The high costs from frequent forced upgrades, long integration cycles, and complex operations infrastructures can only be alleviated by migrating away from a mainframe environment.  Further, data centers are planning for cloud enablement pinned on principles of operating at significantly lower cost, very low upfront investment, operating on commodity hardware and open, standards based systems, and decoupling of hardware, infrastructure software, and business applications. These operating principles are in direct contrast with the principles of operating businesses on mainframes. By utilizing technologies such as Oracle Tuxedo, Oracle Coherence, and Oracle GoldenGate, businesses are able to quickly and safely migrate away from their IBM mainframe environments. Further, running Oracle Tuxedo and Oracle Coherence on Oracle Exalogic, the first and only integrated cloud machine on the market, Oracle customers can not only run their applications on standards-based open systems, significantly cutting their time to market and costs, they can start their journey of cloud enabling their mainframe applications. Oracle Tuxedo re-hosting tools and techniques can provide automated migration coverage for more than 95% of mainframe application assets, at a fraction of the cost Oracle GoldenGate can migrate data from mainframe systems to open systems, eliminating risks associated with the data migration Oracle Coherence hosts transactional data in memory providing mainframe-like data performance and linear scalability Running Oracle software on top of Oracle Exalogic empowers customers to start their journey of cloud enabling their mainframe applications Join us in a series of events across the globe where you you'll learn how you can build your enterprise cloud and add tremendous value to your business. In addition, meet with Oracle experts and your peers to discuss best practices and see how successful organizations are lowering total cost of ownership and achieving rapid returns by moving to the cloud. Register for the Oracle Fusion Middleware Forum event in a city new you!

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• Read-only lock on a SharePoint site collection, or Why can't I edit anymore?

  - by PeterBrunone

  Monday morning, the calls started.  For some reason, long-time users were unable to edit list items.  I figured we had a permissions issue, so I popped in to look at the Site Settings -- and found that I couldn't.  A quick trip to Central Administration showed that I was still listed as a Site Collection Administrator, but I had no power at all on the site collection in question.A quick glance at the logs told me that the server had recently shut down unexpectedly (this is a Hyper-V virtual machine).  Apparently, in the confusion, somehow SharePoint decided to lock the site collection as Read Only.  This can be remedied in one of two ways:1)  In Central Administration, go to Application Management->SharePoint Site Management->Site collection quotas and locks.  Once you have arrived, select the correct application and site collection, and you will have the opportunity to view and set the lock status of the collection (it most likely will be set to "Read-only", and you'll want to move that radio button to "Not locked").2)  Fire up stsadm and issue the following command:stsadm -o setsitelock -url http://myportalsitecollection -lock none

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• DATEFROMPARTS

  - by jamiet

  I recently overheard a remark by Greg Low in which he said something akin to "the most interesting parts of a new SQL Server release are the myriad of small things that are in there that make a developer's life easier" (I'm paraphrasing because I can't remember the actual quote but it was something like that). The new DATEFROMPARTS function is a classic example of that . It simply takes three integer parameters and builds a date out of them (if you have used DateSerial in Reporting Services then you'll understand). Take the following code which generates the first and last day of some given years: SELECT 2008 AS Yr INTO #Years UNION ALL SELECT 2009 UNION ALL SELECT 2010 UNION ALL SELECT 2011 UNION ALL SELECT 2012SELECT [FirstDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 101))),      [LastDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 1231)))FROM   #Years y here are the results: That code is pretty gnarly though with those CONVERTs in there and, worse, if the character string is constructed in a certain way then it could fail due to localisation, check this out: SET LANGUAGE french;SELECT dt,Month_Name=DATENAME(mm,dt)FROM   (       SELECT  dt = CONVERT(DATETIME,CONVERT(CHAR(4),y.[Yr]) + N'-01-02')       FROM    #Years y       )d;SET LANGUAGE us_english;SELECT dt,Month_Name=DATENAME(mm,dt)FROM   (       SELECT  dt = CONVERT(DATETIME,CONVERT(CHAR(4),y.[Yr]) + N'-01-02')       FROM    #Years y       )d; Notice how the datetime has been converted differently based on the language setting. When French, the string "2012-01-02" gets interpreted as 1st February whereas when us_english the same string is interpreted as 2nd January. Instead of all this CONVERTing nastiness we have DATEFROMPARTS: SELECT [FirstDayOfYear] = DATEFROMPARTS(y.[Yr],1,1),    [LasttDayOfYear] = DATEFROMPARTS(y.[Yr],12,31)FROM   #Years y How much nicer is that? The bad news of course is that you have to upgrade to SQL Server 2012 or migrate to SQL Azure if you want to use it, as is the way of the world! Don't forget that if you want to try this code out on SQL Azure right this second, for free, you can do so by connecting up to AdventureWorks On Azure. You don't even need to have SSMS handy - a browser that runs Silverlight will do just fine. Simply head to https://mhknbn2kdz.database.windows.net/ and use the following credentials: Database AdventureWorks2012 User sqlfamily Password sqlf@m1ly One caveat, SELECT INTO doesn't work on SQL Azure so you'll have to use this instead: DECLARE @y TABLE ( [Yr] INT);INSERT @y([Yr])SELECT 2008 AS Yr UNION ALL SELECT 2009 UNION ALL SELECT 2010 UNION ALL SELECT 2011 UNION ALL SELECT 2012;SELECT [FirstDayOfYear] = DATEFROMPARTS(y.[Yr],1,1),      [LastDayOfYear] = DATEFROMPARTS(y.[Yr],12,31)FROM @y y;SELECT [FirstDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 101))),      [LastDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 1231)))FROM @y y; @Jamiet

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• Raid Shows Up as Multiple Drives - Can't Mount

  - by manyxcxi

  I have a single hard drive that the OS is installed on and I have Sil raid card installed with two matching 500GB hdds set up in Raid 0 and formatted- they're completely empty. For whatever reason they are showing up as /dev/sdb and /dev/sdc and not as a single hard drive. I used fdisk to format both raid drives as Linux raid auto (fd) but I cannot mount either device and dmraid doesn't seem to want to work, what step am I missing? When I installed 9.04 oh so long ago it seems like it recognized and automatically did everything that needed to be done, now I'm stuck. dmraid Output root@tripoli:~# dmraid -r /dev/sdc: sil, "sil_biaebhadcfcb", stripe, ok, 976771072 sectors, data@ 0 /dev/sdb: sil, "sil_biaebhadcfcb", stripe, ok, 976771072 sectors, data@ 0 root@tripoli:~# dmraid -ay RAID set "sil_biaebhadcfcb" already active fdisk Output root@tripoli:~# fdisk -l Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000b9b01 Device Boot Start End Blocks Id System /dev/sda1 * 1 32 248832 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 32 60802 488134657 5 Extended /dev/sda5 32 60802 488134656 8e Linux LVM Disk /dev/sdb: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x6ead5c9a Device Boot Start End Blocks Id System /dev/sdb1 1 60801 488384001 fd Linux raid autodetect Disk /dev/sdc: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xe6e2af28 Device Boot Start End Blocks Id System /dev/sdc1 1 60801 488384001 fd Linux raid autodetect

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• Which language is more suitable heavy file tasks?

  - by All

  I need to write a script (based on basic functions) to process /image/audio/video files. The process is mainly filesystem tasks and converts. The database of files has been stored by mysql. The script is simple but cause heavy tasks on the system; for example renaming/converting/copying thousands of file in a run. The script does not read the content of files into memory, it just manage the commands for sub-processes. The main weight is on the communication with filesystem. The script will be used regularly for new files. My concern is about performance. I am thinking of Shell script a complied language like C Please advise which programming language is more suitable for this purpose and why? UPDATE: An example is to scan a folder for images, convert them with ImageMagick, move files to destination folder, get file info, then update the database. As you can see, the process has no room for optimization, and most of languages have similar APIs for popular programs like ImageMagick, MySQL, etc. Thus, it can be written in any language. I just wish to reduce resource usage by speeding up the long loop. NOTE: I know that questions about comparing languages are not favorable, but I really had problem to choose, because the problems can appear in action.

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• What triggered the popularity of lambda functions in modern mainstream programming languages?

  - by Giorgio

  In the last few years anonymous functions (AKA lambda functions) have become a very popular language construct and almost every major / mainstream programming language has introduced them or is planned to introduce them in an upcoming revision of the standard. Yet, anonymous functions are a very old and very well-known concept in Mathematics and Computer Science (invented by the mathematician Alonzo Church around 1936, and used by the Lisp programming language since 1958, see e.g. here). So why didn't today's mainstream programming languages (many of which originated 15 to 20 years ago) support lambda functions from the very beginning and only introduced them later? And what triggered the massive adoption of anonymous functions in the last few years? Is there some specific event, new requirement or programming technique that started this phenomenon? IMPORTANT NOTE The focus of this question is the introduction of anonymous functions in modern, main-stream (and therefore, maybe with a few exceptions, non functional) languages. Also, note that anonymous functions (blocks) are present in Smalltalk, which is not a functional language, and that normal named functions have been present even in procedural languages like C and Pascal for a long time. Please do not overgeneralize your answers by speaking about "the adoption of the functional paradigm and its benefits", because this is not the topic of the question.

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• In Excel, given a worksheet "A", how do you create a sheet "B" that has a subset of the rows in "A"?

  - by user32706

  In Excel 2007, I have a sheet full of data "A". One of the columns in sheet "B" is called "Valid" and has either "yes" or "no". I've created a second sheet "B". It's easy to make each row in "A" appear in "B" if the row is valid using an 'if' statement in each cell. But if it's invalid, there's a blank row. I need "B" to show only the rows from "A" that are valid. TWO BIG CAVEATS: - No macros - No filtering (for long and complicated reasons). I feel like it might be possible with vlookup used cleverly, but so far, I'm stumped.

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• Grading an algorithm: Readability vs. Compactness

  - by amiregelz

  Consider the following question in a test \ interview: Implement the strcpy() function in C: void strcpy(char *destination, char *source); The strcpy function copies the C string pointed by source into the array pointed by destination, including the terminating null character. Assume that the size of the array pointed by destination is long enough to contain the same C string as source, and does not overlap in memory with source. Say you were the tester, how would you grade the following answers to this question? 1) void strcpy(char *destination, char *source) { while (*source != '\0') { *destination = *source; source++; destionation++; } *destionation = *source; } 2) void strcpy(char *destination, char *source) { while (*(destination++) = *(source++)) ; } The first implementation is straightforward - it is readable and programmer-friendly. The second implementation is shorter (one line of code) but less programmer-friendly; it's not so easy to understand the way this code is working, and if you're not familiar with the priorities in this code then it's a problem. I'm wondering if the first answer would show more complexity and more advanced thinking, in the tester's eyes, even though both algorithms behave the same, and although code readability is considered to be more important than code compactness. It seems to me that since making an algorithm this compact is more difficult to implement, it will show a higher level of thinking as an answer in a test. However, it is also possible that a tester would consider the first answer not good because it's not readable. I would also like to mention that this is not specific to this example, but general for code readability vs. compactness when implementing an algorithm, specifically in tests \ interviews.

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• Finding day of week in batch file? (Windows Server 2008)

  - by Daniel Magliola

  I have a process I run from a batch file, and i only want to run it on a certain day of the week. Is it possible to get the day of week? All the example I found, somehow rely on "date /t" to return "Friday, 12/11/2009", however, in my machine, "date /t" returns "12/11/2009". No weekday there. I've already checked the "regional settings" for my machine, and the long date format does include the weekday. The short date format doesn't, but i'd really rather not change that, since it'll affect a bunch of stuff I do. Any ideas here? Thanks! Daniel

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• Which is the best image hosting site for hosting images for the website? [closed]

  - by rahul dagli

  Possible Duplicate: How to find web hosting that meets my requirements? I currently have a website and blog and using a limited web hosting plan. When I upload images on my hosting server it consumes a lot of bandwidth and space. So I was thinking of hosting images on some-other image hosting site and direct linking it to my site. I found out few sites like imageshack, photobucket, tinypic, imgur. However, I see all have certain restrictions. The features i am looking for are as follows: 1. At least 10gb space 2. At least 500gb bandwidth (bec I hav very high traffic) 3. Very high speed even during heavy load like 1000 visitors accessing every hour. 4. Ultra reliable servers (99.9% uptime) 5. Privacy control 6. Must not ever delete image if inactive 7. Create and manage albums 8. Company that will last long in business atleast for next 10 years. 9. Free of cost 10. Hotlinking/ Directlinking image.

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• Distinguishing the Transport Layer from the Session Layer

  In the OSI communications model, the Session layer manages the creation and removal of the association between two communicating network end points. This can also be called a connection. A connection is maintained while the network end points are communicated between each other in a conversation or session of some unknown length of time. Some connections and sessions only need to last long enough to send a message or a piece of data in one direction. In addition, some sessions may last longer, this typically occurs when one or both of the network end points are  able to terminate it the connection. The transport layer ensures that messages/data are delivered without errors, in sequence, and with no data content losses or data content duplications. It relieves the Session Layer from any concern with the transfer of data between them and their peers. Examples: Session Layer This layer acts like a manager and asks one of its employees (Transport Layer) to move a piece of data/message from one network end-point to another. Transportation Layer This layer takes the request of the Session Layer and moves the data as insturcted, it also double checks the data for any missing or corrupted information after it has been moved. If for some reason the new data does not match the old data then the Transport player will attempt to move the data gain until the data at both locations is in sync.

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• How to add a footer to a table in Microsoft Word?

  - by dewalla

  I have a table that is longer than one page. I have found the option to make the header of the table to be added to the second portion of the table after the page break. Is there a way to do the same thing but with a footer on the table? I want to add a footer so that if my table was 1000 entries long (12 pages), that the first and last row of each page would be consistant; a header and footer for the table. If I edit the rest of the document (above the table) the table will shift up/down and I want to header and footer of the table to remain at the pagge breaks. Any Ideas? PAGE BREAK HEADER OF TABLE TBL TBL TBL TBL TBL TBL TBL TBL TBL TBL TBL TBL FOOTER OF TABLE PAGE BREAK HEADER OF TABLE TBL TBL TBL TBL TBL TBL FOOTER OF TABLE TEXT TEXT TEXT TEXT TEXT TEXT PAGE BREAK

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• How to add a footer to a table in Microsoft Word?

  - by dewalla

  I have a table that is longer than one page. I have found the option to make the header of the table to be added to the second portion of the table after the page break. Is there a way to do the same thing but with a footer on the table? I want to add a footer so that if my table was 1000 entries long (12 pages), that the first and last row of each page would be consistant; a header and footer for the table. If I edit the rest of the document (above the table) the table will shift up/down and I want to header and footer of the table to remain at the pagge breaks. Any Ideas? PAGE BREAK HEADER OF TABLE TBL TBL TBL TBL TBL TBL TBL TBL TBL TBL TBL TBL FOOTER OF TABLE PAGE BREAK HEADER OF TABLE TBL TBL TBL TBL TBL TBL FOOTER OF TABLE TEXTTEXTETEXT PAGE BREAK

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