03-01-2008
System calls are subroutines or functions that can be invoked from a C program. The program that invokes one must test the reurn code to see if it worked. If not, the program may display an error. But what message, if any, will be displayed is up to the programmer who wrote the program.
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. 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
6. 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
7. 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
8. UNIX for Dummies Questions & Answers
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
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
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
LEARN ABOUT SUSE
assert_perror
ASSERT_PERROR(3) Linux Programmer's Manual ASSERT_PERROR(3)
NAME
assert_perror - test errnum and abort
SYNOPSIS
#define _GNU_SOURCE
#include <assert.h>
void assert_perror(int errnum);
DESCRIPTION
If the macro NDEBUG was defined at the moment <assert.h> was last included, the macro assert_perror() generates no code, and hence does
nothing at all. Otherwise, the macro assert_perror() prints an error message to standard error and terminates the program by calling
abort(3) if errnum is nonzero. The message contains the filename, function name and line number of the macro call, and the output of str-
error(errnum).
RETURN VALUE
No value is returned.
CONFORMING TO
This is a GNU extension.
BUGS
The purpose of the assert macros is to help the programmer find bugs in his program, things that cannot happen unless there was a coding
mistake. However, with system or library calls the situation is rather different, and error returns can happen, and will happen, and
should be tested for. Not by an assert, where the test goes away when NDEBUG is defined, but by proper error handling code. Never use
this macro.
SEE ALSO
abort(3), assert(3), exit(3), strerror(3), feature_test_macros(7)
COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU
2002-08-25 ASSERT_PERROR(3)