Programming :: Passing The Char * Vector Argument?
Jun 19, 2010
I am trying to simulate a shell. So what I do is checking of having the parameters from standard input, suc as "/bin/ls -l /home/france/Documents", and then passing them to function execute, which at some point calls execvp(argv,argv)The problem is that I don't succeed in using these arguments, while if I call execvp(paramList,paramList) it works!!!! Where paramList is exactly what I would put on standard input, but defined statically.
As you can see we have a problem. If we use a wchar_t instead the string wont be formatted right we need to prefix L in front. If we use char16_t we need to prefix a u in front. Is there a was to make the generic without resorting the the std::string class?
I want to use vfprintf with the char * on 64-bit. Here is the sample code:
In this code, I am getting warning: passing argument 3 of vfprintf from incompatible pointer type I have done sizeof(va_list) on 64-bit, and its 24 bytes. I don't know how am I suppose to use the va_list this way.
Programming in C.I have two char arrays.char buf1;char buf2;Aren't buf1 and buf2 also pointers?I read in 1024 bytes into buf1 which contain about 300 bytes of characters with newlines. The data is basically a few English sentences. I'm trying to scan buf1 for newlines and then stop at the 1st newline and copy the rest of the data from that 1st newline into buf2.So I run a for loop to look for that new line.
Line 43 points at the snprintf() command.I think the error has to do with the function being virtual and the const after the function definition, however although I have been looking really hard I have not being able to find the reason nor the solution to the problem.
One workaround that I know is moving the block of source withing the virtual function, in the constructor, however having read around (boost library exceptions tutorials) it specifically said that formating of errors messages should not take place withing the construction of objects because we are risking throwing an exceptions and messing up the flow order.
I have a number of projects, say test1, test2, test3,. I want to make and install all of them in exactly the same way; so I would like to say make test2 make install test2 with the same Makefile.
In other words, I would like to pass the argument test2 (or just 2) to the Makefile, so this is taken as the target for make or make install. This must be a common wish; but I don't see any appropriate option with "man make" on my Fedora-12 system.
I've modified a program to show * instead of letters when typing a password. I'm trying to make it so that when pressing backspace a * will be removed.Here's a rough example. The problem is that when trying to do this in the real program,' is not recognized as backspace.
I'm writing the Diffie-Hellman key exchange system using GMP to handle big integers. For the most part, everything works. I can convert the string to mpz_t, set up the keys and everything, and encrypt it fine. Its the decrypting I'm having issues with. What I'm using is mpz_xor() for both. To encrypt I'm doing mpz_xor(buffer, mpz_of_text, secret_key), and to decrypt I'm doing mpz_xor(buffer, mpz_of_cipher, secret_key).
For one character, it semi-works...it'll decrypt it fine, but it'll return it as it's ASCII value (i.e.: if I encrypt "A", it'll decrypt it as 65). Which, I can easily just do sprintf(decrypted_buffer, "%c", 65) for example and be fine. But, when I'm sending text bigger than one character, the encryption for AB gives me something like 1061043 after running the decrypting xor on it.
Has anyone ever done this before or can point me in some directions? Perhaps other algorithms to try? I know XOR isn't the most secure encryption method to use, but at the time I wasn't sure what else to use. I'm really just having a hard time trying to convert a mpz_t to a character string. I've looked at mpz_get_str() and it works before running encryption (i.e.: using mpz_set_str() to create a mpz of a string, then calling mpz_get_str() to change it back). Maybe my XOR method is wrong? Here's the code I'm using:
/** * str2mpz() * b The current buffer of text to convert [in] * m The mpz_t variable to store converted text [out]
I would like to create a small C tool. I encounter a problem of how to make a function to check an input chars contains numbers (started from the second element).
char *mychar= "a3547"; (The result of function checking this is true) char *another_char = "t6548"; (The result of function checking this is true) char *next_char = "appl3"; (The result of function checking this is false) char *new_char = "b1aa3"; (The result of function checking this is false)