prannoy mittal - Page 2

printing double in binary

- by Happy Mittal

In Thinking in C++ by Bruce eckel, there is a program given to print a double value in binary.(Chapter 3, page no. 189) int main(int argc, char* argv[]) { if(argc != 2) { cout << "Must provide a number" << endl; exit(1); } double d = atof(argv[1]); unsigned char* cp = reinterpret_cast<unsigned char*>(&d); for(int i = sizeof(double); i > 0 ; i -= 2) { printBinary(cp[i-1]); printBinary(cp[i]); } } Here while printing cp[i] when i=8(assuming double is of 8 bytes), wouldn't it be undefined behaviour? I mean this code doesn't work as it doesn't print cp[0].

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Function declaration in C and C++

- by Happy Mittal

I have two C++ files, say file1.cpp and file2.cpp as //file1.cpp #include<cstdio> void fun(int i) { printf("%d\n",i); } //file2.cpp void fun(double); int main() { fun(5); } When I compile them and link them as c++ files, I get an error "undefined reference to fun(double)". But when I do this as C files, I don't get error and 0 is printed instead of 5. Please explain the reason. Moreover I want to ask whether we need to declare a function before defining it because I haven't declared it in file1.cpp but no error comes in compilation.

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string substitution regular expression not working in tcl

- by Puneet Mittal

i am trying to replace all the special characters including white space, hyphen, etc, to underscore, from a string variable in tcl. I wrote the code below but it doesn't seem to be working. set varname $origVar puts "Variable Name :>> $varname" if {$varname != ""} { regsub -all {[\s-\]\[$^?+*()|\\%&#]} $varname "_" $newVar } puts "New Variable :>> $newVar" one issue is that, instead of replacing the string in $varname, it is replacing the data inside $origVar. No idea why, and also i read the example code (for proper syntax) in my tcl book and according to that it should be something like this regsub -all {[\s-][$^?+*()|\\%&#]} $varname "_" newVar so i used the same syntax but it didn't work and gave the same result as modifying the $origVar instead of required $varname value.

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initialization of objects in c++

- by Happy Mittal

I want to know, in c++, when does the initialization of objects take place? Is it at the compile time or link time? For ex: //file1.cpp extern int i; int j=5; //file2.cpp ( link with file1.cpp) extern j; int i=10; Now, what does compiler do : according to me, it allocates storage for variables. Now I want to know : does it also put initialization value in that storage or is it done at link time?

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makefile extension

- by Happy Mittal

I wanted to create a makefile. So I wrote instructions in a notepad file. But what extension should I give while saving this file?

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static initialization confusion

- by Happy Mittal

I am getting very confused in some concepts in c++. For ex: I have following two files //file1.cpp class test { static int s; public: test(){s++;} }; static test t; int test::s=5; //file2.cpp #include<iostream> using namespace std; class test { static int s; public: test(){s++;} static int get() { return s; } }; static test t; int main() { cout<<test::get()<<endl; } Now My question is : 1. How two files link successfully even if they have different class definitions? 2. Are the static member s of two classes related because I get output as 7. Please explain this concept of statics.

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commands executing in piping in UNIX

- by Happy Mittal

when I write a command $ echo date then it prints "date" as it is i.e it doesn't run date program. But when I write $ echo date | wc then correct answer is produced as if date was run. How piping is making difference here ? Please explain.

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static initialization order fiasco

- by Happy Mittal

I was reading about SIOF from a book and it gave an example : //file1.cpp extern int y; int x=y+1; //file2.cpp extern int x; y=x+1; Now My question is : In above code..will following things happen ? 1. while compiling file1.cpp, compiler leaves y as it is i.e doesn't allocate storage for it. 2. compiler allocates storage for x, but doesn't initialize it. 3. While compiling file2.cpp, compiler leaves x as it is i.e doesn't allocate storage for it. 4. compiler allocates storage for y, but doesn't initialize it. 5. While linking file1.o and file2.o, now let file2.o is initialized first, so now: Does x gets initial value of 0? or doesn't get initialized?

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output redirection in UNIX

- by Happy Mittal

I am a beginner in UNIX. I am finding some difficulty in input/output redirection. ls -l temp cat temp Here why temp file is shown in the list and moreover, it is showing 0 characters. wc temp temp cat temp here output is 0 0 0 temp. Why lines, words, characters are 0. Please help me to undestand this concept.

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SQL SERVER – Winners – Contest Win Joes 2 Pros Combo (USD 198)

- by pinaldave

Earlier this week we had contest ran over the blog where we are giving away USD 198 worth books of Joes 2 Pros. We had over 500+ responses during the five days of the contest. After removing duplicate and incorrect responses we had a total of 416 valid responses combined total 5 days. We got maximum correct answer on day 2 and minimum correct answer on day 5. Well, enough of the statistics. Let us go over the winners’ names. The winners have been selected randomly by one of the book editors of Joes 2 Pros. SQL Server Joes 2 Pros Learning Kit 5 Books Day 1 Winner USA: Philip Dacosta India: Sandeep Mittal Day 2 Winner USA: Michael Evans India: Satyanarayana Raju Pakalapati Day 3 Winner USA: Ratna Pulapaka India: Sandip Pani Day 4 Winner USA: Ramlal Raghavan India: Dattatrey Sindol Day 5 Winner USA: David Hall India: Mohit Garg I congratulate all the winners for their participation. All of you will receive emails from us. You will have to reply the email with your physical address. Once you receive an email please reply within 3 days so we can ship the 5 book kits to you immediately. Bonus Winners Additionally, I had announced that every day I will select a winner from the readers who have left comments with their favorite blog post. Here are the winners with their favorite blog post. Day 1: Prasanna kumar.D [Favorite Post] Day 2: Ganesh narim [Favorite Post] Day 3: Sreelekha [Favorite Post] Day 4: P.Anish Shenoy [Favorite Post] Day 5: Rikhil [Favorite Post] All the bonus winners will receive my print book SQL Wait Stats if your shipping address is in India or Pluralsight Subscription if you are outside India. If you are not winner of the contest but still want to learn SQL Server you can get the book from here. Amazon | 1 | 2 | 3 | 4 | 5 | Flipkart | Indiaplaza Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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