Sponsored Content
Full Discussion: About system calls.
Top Forums UNIX for Dummies Questions & Answers About system calls. Post 302306900 by pludi on Tuesday 14th of April 2009 07:35:51 AM
Old 04-14-2009
System calls are usually done by setting a certain register to a certain value and raising a certain interrupt, thus telling the kernel to do a certain thing to a certain different address.
Anything written as "certain ..." is different for each OS and sometimes even versions of the same OS. System calls are usually hidden behind the C library and should stay there, unless you want to start writing assembler code.
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

System Calls

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

System calls for cp and mv

Which system calls are made for operations cp and mv (2 Replies)
Discussion started by: gaurava99
2 Replies

3. UNIX for Dummies Questions & Answers

System calls?

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

System calls ?

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

Using system calls

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

System calls

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

system calls

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. UNIX for Dummies Questions & Answers

system calls in C

Hello, how would i be able to call ps in C programming? thanks, ---------- Post updated at 01:39 AM ---------- Previous update was at 01:31 AM ---------- here's the complete system call, ps -o pid -p %d, getpit() (2 Replies)
Discussion started by: l flipboi l
2 Replies

9. UNIX for Dummies Questions & Answers

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... (1 Reply)
Discussion started by: bjhum33
1 Replies

10. Programming

Are system calls in c language only????

Hi friends, I have three questions. 1) What are system calls? 2) Is it necessary that system calls be in c language (in unix operating system)? 3) Importance of c language when programming in unix environment??? Looking forward to your wonderful replies! ... (2 Replies)
Discussion started by: gabam
2 Replies
siginterrupt(3) 					     Library Functions Manual						   siginterrupt(3)

Name
       siginterrupt - allow signals to interrupt system calls

Syntax
       siginterrupt(sig, flag)
       int sig, flag;

Description
       The  system call is used to change the system call restart behavior when a system call is interrupted by the specified signal.  If the flag
       is false (0), then system calls will be restarted if they are interrupted by the specified signal and no data  has  been  transferred  yet.
       System call restart is the default behavior on 4.2 BSD.

       If  the flag is true (1), then restarting of system calls is disabled.  If a system call is interrupted by the specified signal and no data
       has been transferred, the system call will return -1 with errno set to EINTR.  Interrupted system calls that have started transferring data
       will  return the amount of data actually transferred.  System call interrupt is the signal behavior found on 4.1 BSD and AT&T System V sys-
       tems.

       Note that the new signal handling semantics are not altered in any other way.  Most notably, signal handlers always remain installed  until
       explicitly  changed  by a subsequent call, and the signal mask operates as documented in Programs may switch between restartable and inter-
       ruptible system call operation as often as desired in the execution of a program.

       Issuing a call during the execution of a signal handler will cause the new action to take place on the next signal to be caught.

Environment
       This library routine uses an extension of the system call that is not available in ULTRIX 2.0 or earlier versions.  Hence it should not	be
       used if backward compatibility is needed.

Return Values
       A 0 value indicates that the call succeeded.  A -1 value indicates that an invalid signal number has been supplied.

See Also
       sigvec(2), sigblock(2), sigpause(2), sigsetmask(2)

4.3 Berkeley Distribution													   siginterrupt(3)
All times are GMT -4. The time now is 12:33 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy