What does an upside down question mark mean in the output in C?
Hi, I get an upside down question mark as an output from of of my function, what does it mean exactly? ...
Hi, I get an upside down question mark as an output from of of my function, what does it mean exactly? ...
I know all about batch files and made them before, but I'm unclear on what a makefile is. It looks like a batch file. What are the similarities and diffferences? ...
Hi, I built two programs, one using malloc and other one using mmap. The execution time using mmap is much less than using malloc. I know for example that when you're using mmap you avoid read/writes calls to the system. And the memory access are less. But are there any other reasons for the advantages when using mmap over malloc? T...
I am a bit confused in the idea of code injection in C. If somebody could explain it and show how its done I would appreciate it. So lets say in C you have some Char array of size 512 which is being written to the contents of a socket of length 1024, and that char array now holds some sort of code but only half of what was written. Ho...
I'm using XCode and I'm trying to open a file that gets passed as a command line argument, and output the number of lines that gets passed as a command line argument of that file, to the console in C. In XCode, my arguments are "test.rtf", and "5". My rtf looks like: line 1 test line 2 test line 3 test line 4 test line 5 test line 6 t...
Hi, I'm trying to test a rather threading-sensitive area in my program and was wondering if there's a way to force gcc to insert a call after every instruction it emits so that I can manually yield to a different thread? Thanks, Robert ...
I've just started a job where I'm programming in C on a Mac, which is my first experience using a Mac for development. For now I'm using XCode as my editor, then using make/gcc/svn at the command line for compiling and source control. Is there a good, full featured IDE out there for Macs that will compile C code (something comparable to...
I'm used to old-style C and and have just recently started to explore c99 features. I've just one question: Will my program compile successfully if I use c99 in my program, the c99 flag with gcc and link it with prior c99 libraries? So, should I stick to old C89 or evolve? Thanks. ...
I am sending/receiving data over a serial line in Linux and I would like to find the delay between characters. Modbus uses a 3.5 character delay to detect message frame boundaries. If there is more than a 1.5 character delay, the message frame is declared incomplete. I'm writing a quick program in C which is basically fd = open(MODEM...
I'm looking for a series of C problems (with solutions) that I can use to build my C skills. I already understand the basics of the language, the syntax, and the semantics. I am looking for a series of problems that will help me hone my skills, not a set of simple questions that you'd see in an introductory programming class. ...
Hy. I'm thinking about best way to write C define processor that would be able to handle macros.Unfortunately nothing intelligent comes to my mind. It should behave exactly like one in C, so it handles expressions like this: #define max(a, b) (a > b ? a : b) printf("%d\n", max(a, b)); Or this: #define F 10 #define max(a, b) (a > b ...
Dear developers, When I compile ALSA's pcm_min.c example with gcc -Wall -lasound pcm_min.c -o pcm_min Everything is fine, but running it, I get the white noise as expected, but I also get this warning/error: Short write (expected 16384, wrote 7616) Which comes from the last if-statement. #include <alsa/asoundlib.h> static char *...
I am trying to get the free space on the / folder using statvfs call from java, I have check the size of statvfs struct from c it shows 44 bytes, I have allocated a byte buffer using java.nio.ByteBuffer.allocateDirect 44 bytes, and it's order is set to 44 bytes. when i call statvfs i get a return value of 0, so i am assuming call is suc...
I'm programming in C in Visual Studio 2005. I have a multi-threaded program, but that's not especially important here. How can I determine (approximately) how much stack space my threads use? The technique I was planning to use is setting the stack memory to some predetermined value, say 0xDEADBEEF, running the program for a long time...
Can anyone tell me how to write a C program to compare numbers(including negative numbers) without using logical operators? ...
I'm looking for a way to pass in a FILE * to some function so that the function can write to it with fprintf. This is easy if I want the output to turn up in an actual file on disk, say. But what I'd like instead is to get all the output as a string (char *). The kind of API I'd like is: /** Create a FILE object that will direct writ...
Just curious. I may be wrong, but as far as I know, most languages are created using 'C' sources. For example: perl , php , python, java(?), go ... Is there any language that doesn't use C as a low level interpreter/compiler ? (fortran ?) ...
I need to write a few c header wrappers for a new programming language and would like something like gccxml but without the full dependency on gcc and the problems it gives on a windows system. Just needs to read C not C++. Output in any format is okay as long it is fully documented. Need it for Curl, SQLite, GTK2, SDL, OpenGL, Win32 A...
Can I use malloc to add symbol table entries? How do I traverse the table to check if something is already there? ...
using c how do I wait for PID X to exit when it is not a child of my current process? Kill(pid, SIGTERM); waitpid(pid,NULL,0); The above does not work as 'pid' is not a child process. ...