Problem in determining runlevel through a C program
Hi,
I am trying with the following code to retrieve the runlevel of my Linux Ubuntu 8.04 system by reading the "utmp" database. But I am getting blank output. May I know what correction I should do inorder to make this program to work?
Last edited by royalibrahim; 05-04-2011 at 09:42 AM..
Hi,
Is it possible to specify runlevel
from bootloader command line?
I would like to override settings from /etc/inittab
without changing it.
Thanks (2 Replies)
Is it possible to give multiple runlevel options during boot up.. When the Welcome screen appears, i want to give multiple runlevel options.. So the user can boot into any desired runlevel he wants.. Found this kinda interesting.. Any hints and solutions please? (2 Replies)
Hi guys
I'm having trouble with trying to create a script which calculates the grade of a student and the marks out of 300.
The grades are:
0-49% fail
50-59% pass
60-69% credit pass
70-79% distinction
80-100% high distinction
less than 0 or greater than 100 displays error message.
My... (1 Reply)
I got the following code, it partially works. Can someone tell me why it partially doenst work?
#!/bin/sh
file=$1
if
then
echo "File is a directory"
else
echo "File is not a directory!"
fi
heres the output:
philip@philip-laptop:~/Desktop$ sh exFive.sh test.java
File is... (4 Replies)
Ok, I am attempting to add a new program to startup during the runlevel 3. I am using Suse 10.
I made a script lets call it foostart and placed it in /etc/init.d. It has 777 permissions on the script.
I then created a link ln -s /etc/init.d/foostart /etc/init.d/rc3.d/S99foostart
But during... (9 Replies)
I wrote a program which will send a message to multiple clients(i.e, broadcasting) that are connected to a server.Once when the client receives a message from the server ,the client should read a file in the server and display it in the client.The client which responds (i.e, client wants all the... (3 Replies)
hi all
i have to run a script in run level 1 automatically i.e when i give init 1 from runlevel 3 that script should run after entering into runlevel 1.
where can i put that script so that it will run as i said above..???
something similar to rc.local but this will run in runlevel 3(... (1 Reply)
hi all
i am using solaris 10 with run level 3.(Graphical Interface). I am a beginner to solaris so that i just want to do some R&D with my machine. I decided to boot into the command line interface, so i go througth the internet and find that the following command should be given to boot into the... (8 Replies)
Discussion started by: kingston
8 Replies
LEARN ABOUT REDHAT
setutent
GETUTENT(3) Library functions GETUTENT(3)NAME
getutent, getutid, getutline, pututline, setutent, endutent, utmpname - access utmp file entries
SYNOPSIS
#include <utmp.h>
struct utmp *getutent(void);
struct utmp *getutid(struct utmp *ut);
struct utmp *getutline(struct utmp *ut);
struct utmp *pututline(struct utmp *ut);
void setutent(void);
void endutent(void);
void utmpname(const char *file);
DESCRIPTION
utmpname() sets the name of the utmp-format file for the other utmp functions to access. If utmpname() is not used to set the filename
before the other functions are used, they assume _PATH_UTMP, as defined in <paths.h>.
setutent() rewinds the file pointer to the beginning of the utmp file. It is generally a Good Idea to call it before any of the other
functions.
endutent() closes the utmp file. It should be called when the user code is done accessing the file with the other functions.
getutent() reads a line from the current file position in the utmp file. It returns a pointer to a structure containing the fields of the
line.
getutid() searches forward from the current file position in the utmp file based upon ut. If ut->ut_type is RUN_LVL, BOOT_TIME, NEW_TIME,
or OLD_TIME, getutid() will find the first entry whose ut_type field matches ut->ut_type. If ut->ut_type is one of INIT_PROCESS,
LOGIN_PROCESS, USER_PROCESS, or DEAD_PROCESS, getutid() will find the first entry whose ut_id field matches ut->ut_id.
getutline() searches forward from the current file position in the utmp file. It scans entries whose ut_type is USER_PROCESS or
LOGIN_PROCESS and returns the first one whose ut_line field matches ut->ut_line.
pututline() writes the utmp structure ut into the utmp file. It uses getutid() to search for the proper place in the file to insert the
new entry. If it cannot find an appropriate slot for ut, pututline() will append the new entry to the end of the file.
RETURN VALUE
getutent(), getutid(), getutline() and pututline() return a pointer to a static struct utmp on success, and NULL on failure.
EXAMPLE
The following example adds and removes a utmp record, assuming it is run from within a pseudo terminal. For usage in a real application,
you should check the return values of getpwuid() and ttyname().
#include <string.h>
#include <stdlib.h>
#include <pwd.h>
#include <unistd.h>
#include <utmp.h>
int main(int argc, char *argv[])
{
struct utmp entry;
system("echo before adding entry:;who");
entry.ut_type=USER_PROCESS;
entry.ut_pid=getpid();
strcpy(entry.ut_line,ttyname(0)+strlen("/dev/"));
/* only correct for ptys named /dev/tty[pqr][0-9a-z] */
strcpy(entry.ut_id,ttyname(0)+strlen("/dev/tty"));
time(&entry.ut_time);
strcpy(entry.ut_user,getpwuid(getuid())->pw_name);
memset(entry.ut_host,0,UT_HOSTSIZE);
entry.ut_addr=0;
setutent();
pututline(&entry);
system("echo after adding entry:;who");
entry.ut_type=DEAD_PROCESS;
memset(entry.ut_line,0,UT_LINESIZE);
entry.ut_time=0;
memset(entry.ut_user,0,UT_NAMESIZE);
setutent();
pututline(&entry);
system("echo after removing entry:;who");
endutent();
return 0;
}
FILES
/var/run/utmp database of currently logged-in users
/var/log/wtmp database of past user logins
CONFORMING TO
XPG 2, SVID 2, Linux FSSTND 1.2
In XPG2 and SVID2 the function pututline() is documented to return void, and that is what it does on many systems (AIX, HPUX, Linux
libc5). HPUX introduces a new function _pututline() with the prototype given above for pututline() (also found in Linux libc5).
All these functions are obsolete now on non-Linux systems. POSIX 1003.1-2001, following XPG4.2, does not have any of these functions, but
instead uses
#include <utmpx.h>
struct utmpx *getutxent(void);
struct utmpx *getutxid(const struct utmpx *);
struct utmpx *getutxline(const struct utmpx *);
struct utmpx *pututxline(const struct utmpx *);
void setutxent(void);
void endutxent(void);
The utmpx structure is a superset of the utmp structure, with additional fields, and larger versions of the existing fields. The corre-
sponding files are often /var/*/utmpx and /var/*/wtmpx.
Linux glibc on the other hand does not use utmpx since its utmp structure is already large enough. The functions getutxent etc. are aliases
for getutent etc.
SEE ALSO utmp(5)
1996-07-25 GETUTENT(3)