how to differentiate system call from library call


 
Thread Tools Search this Thread
Top Forums UNIX for Advanced & Expert Users how to differentiate system call from library call
# 1  
Old 07-19-2007
how to differentiate system call from library call

Hi,
Ho do I differentiate system call from library call?
for example if I am using chmod , how do I find out if it is a system call or library call?

Thanks
Muru
# 2  
Old 07-19-2007
Check the man page. For chmod it will be something like chmod(2). Your OS will have specific sections of the man pages dedicated to things like system calls, user commands, admin commands, files and so on. The (2) usually means system call on most systems. Now check the man page for something else like fprintf. You will see either fprintf(3C) or fprintf(3). On most systems, section 3/3C is for library functions.
# 3  
Old 07-20-2007
Quote:
Originally Posted by muru
How do I differentiate system call from library call?
Look in "/usr/include/sys/syscall.h" or equivalent for a macro identifying an index for that call

Quote:
Originally Posted by muru
for example if I am using chmod , how do I find out if it is a system call or library call?
You may not be able to as you link with libc.a (or similar) and that provides the calls, these may be a full implementation or a wrapper around the actual system call.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

system call

Trying to figure out a load issue with a webserver. I have traced a php script and noticed the following connect(4, {sa_family=AF_INET, sin_port=htons(3306), sin_addr=inet_addr("XX.XX.XX.XX")}, 16) = -1 EINPROGRESS (Operation now in progress) <0.000035> poll(, 1, 2000) = 1 () <0.000120>... (5 Replies)
Discussion started by: rajan007
5 Replies

2. Programming

need help with system call

hi everyone i wrote a system call and compiled the kernel succesfully... my system call is in a file in the kernel folder named my_syscall1.c (kernel/my_syscall1.c) the header file for this system call i added it in the folder include like this include/my_syscall1/my_syscall1.h my problem is... (2 Replies)
Discussion started by: demis87
2 Replies

3. Programming

system call

I have a cgi script which is called after certain time interval, which has this: system ("ls -l /tmp/cgic* | grep -v \"cgicsave.env\" | awk '{print $5}'"); During the execution of this script,the output is 0 sometimes. But due to this the system call is not working at all and doesnt o/p... (2 Replies)
Discussion started by: xs2punit
2 Replies

4. Programming

C:system call

Hi I'm studing the system call. I've written a small program that return the time spent in doing some operations. Now I'd like to write one that return the time spent in user mode of a process. I'm reading that i should use the tms struct: clock_t times(struct tms *buf); struct tms {... (2 Replies)
Discussion started by: Dedalus
2 Replies

5. Shell Programming and Scripting

system call

Hi, How to write a system calls in a script ? > cd $HOME > ls -ltr thanks in advance.. (10 Replies)
Discussion started by: hegdeshashi
10 Replies

6. Infrastructure Monitoring

diffrence between method call and function call in perl

Hello, I have a problem with package and name space. require "/Mehran/DSGateEngineLib/general.pl"; use strict; sub System_Status_Main_Service_Status_Intrusion_Prevention { my %idpstatus; my @result; &General_ReadHash("/var/dsg/idp/settings",\%idpstatus); #print... (4 Replies)
Discussion started by: Zaxon
4 Replies

7. Programming

How to call the c library created by shc

I have written a shell script called square, which prints the square of the input number, eg. > square 4 16 There is a program called shc which compiles the shell scirpt and create a executable file and a c library file, namely square.x and square.x.c repectively. If I would like to... (1 Reply)
Discussion started by: alfredo
1 Replies

8. Shell Programming and Scripting

How to call the c library created by shc

I have written a shell script called square, which prints the square of the input number, eg. > square 4 16 There is a program called shc which compiles the shell scirpt and create a executable file and a c library file, namely square.x and square.x.c repectively. If I would like to... (0 Replies)
Discussion started by: alfredo
0 Replies

9. Programming

c system call

How the c compiler differentiates the system calls and function calls? (1 Reply)
Discussion started by: rangaswamy
1 Replies

10. Shell Programming and Scripting

tcsh user failed to call library in ksh program

Hi folks, I'm trying to organize functions in my ksh program into libraries. If I run my program as any ksh user it will succeed. Only when I run my program as tcsh user (i.e oracle) I failed. Example ======= The ksh code: tornado:/tmp # cat nir.ksh #! /bin/ksh cdromPath=`pwd`... (1 Reply)
Discussion started by: nir_s
1 Replies
Login or Register to Ask a Question