01-31-2012
System calls in UNIX
Hi i am very new to programming in UNIX and don't understand the difference between a system call and a normal function call. Also can I implement system calls from within a program? If so could someone please give me an example of a system call from within a program. Lastly, when creating a program related to systems programming is it necessary to be in a specific shell? Sorry if these questions are pretty basic but I am completely lost here. Any help would be greatly appreciated.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
What does the system call "dup" do?
What is the difference between dup and dup2
I have a fair idea of what it does but I am confused when its coming down to the exact details...
Please help me!:confused: (2 Replies)
Discussion started by: clickonline1
2 Replies
2. UNIX for Dummies Questions & Answers
Which system calls are made for operations cp and mv (2 Replies)
Discussion started by: gaurava99
2 Replies
3. UNIX for Dummies Questions & Answers
open, creat, read, write, lseek and close
Are they all primitive?
:confused:
*Another Question: is there a different between a system call, and an i/o system call? (2 Replies)
Discussion started by: PlunderBunny
2 Replies
4. Solaris
where can i find the differences in System calls between solaris and aix?
also is it possible to find a comprehensive list of them? (1 Reply)
Discussion started by: TECHRAMESH
1 Replies
5. UNIX Desktop Questions & Answers
Hi,
I'm new to UNIX system calls. Can someone share your knowledge as to how exactly system calls should be executed?
Can they be typed like commands such as mkdir on the terminal itself? Also, are there any websites which will show me an example of the output to expect when a system call like... (1 Reply)
Discussion started by: ilavenil
1 Replies
6. Programming
why user is not able to switch from user to kernel mode by writing the function whose code is identical to system call. (1 Reply)
Discussion started by: joshighanshyam
1 Replies
7. BSD
what is the functions and relationship between fork,exec,wait system calls
as i am a beginer just want the fundamentals. (1 Reply)
Discussion started by: sangramdas
1 Replies
8. Programming
#include<unistd.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<stdlib.h>
int main( int argc,char *argv )
{
char buf;
int sourcefile,destfile,n;
if(argc!=3)
{
write(STDOUT_FILENO,"prgm1 <sourcefile> <destination file>\n",50);
... (6 Replies)
Discussion started by: c_d
6 Replies
9. UNIX for Dummies Questions & Answers
Hi all,
I am new here .
I want to know about system call in detail.
As system calls are also function .How system identifies it.:) (2 Replies)
Discussion started by: vishwasrao
2 Replies
10. UNIX for Dummies Questions & Answers
I'm currently studying for my exam, and is practicing with sample exam questions.
However there is a question asking "Name THREE UNIX Directory system calls" and the answer given is "opendir, closedir and readdir", however the next question ask "Why is a write directory system call not included... (1 Reply)
Discussion started by: Izzy123
1 Replies
LEARN ABOUT DEBIAN
allegro_exit
allegro_exit(3alleg4) Allegro manual allegro_exit(3alleg4)
NAME
allegro_exit - Closes down the Allegro system.
SYNOPSIS
#include <allegro.h>
void allegro_exit();
DESCRIPTION
Closes down the Allegro system. This includes returning the system to text mode and removing whatever mouse, keyboard, and timer routines
have been installed. You don't normally need to bother making an explicit call to this function, because allegro_init() installs it as an
atexit() routine so it will be called automatically when your program exits.
Note that after you call this function, other functions like destroy_bitmap() will most likely crash. This is a problem for C++ global
destructors, which usually get called after atexit(), so don't put Allegro calls in them. You can write the destructor code in another
method which you can manually call before your program exits, avoiding this problem.
SEE ALSO
install_allegro(3alleg4), allegro_init(3alleg4), destroy_bitmap(3alleg4), ex3d(3alleg4), exscn3d(3alleg4), exswitch(3alleg4),
exxfade(3alleg4), exzbuf(3alleg4)
Allegro version 4.4.2 allegro_exit(3alleg4)