NULL is defined to be<datatype> *)0 - this means regardless of the underlying architecture
if p == 0 and p is a pointer it is guaranteed to be unassigned. Therefore
Code:
if (p)
if(p==NULL)
evaluate the same. NULL is fairly new. Old C code uses code like (char**)0 all the time. Example - this is in the strtoul definition on the manpage for systems that have C89 compilers.
hi
I wrote the following makefile, I have just one problem, when i type make clean I get the message make 'clean' is up to date and any obj file is removed from my folder, what's wrong?
Thank you
CC = cc
all: es.o elaboration.o
$(CC) -o es es.o elaboration.o
elaboration.o:... (0 Replies)
08-18-2008 11:00 AM
Cluster computing has played a pivotal role in the way research is conducted in educational environments. Because the amount of available money and hardware varies between university researchers, often it's necessary to find a clustering solution that can work well on a small... (0 Replies)
I'm running the following rsync command to sync a directory between the 2 servers:
rsync -az --delete --stats /some_dir/ server_name:/some_dir
I'm getting the following output:
Number of files: 655174
Number of files transferred: 14221
Total file size: 1138531979331 bytes
Total... (0 Replies)
It's been a while since I had to write a Makefile, but I've managed to clobber this together:
SRC=module1.c module2.c
OBJS=$(SRC:%.c=%.o)
HDR=include1.h include2.h
CC=gcc
CFLAGS=-Wall -ggdb -D_XOPEN_SOURCE -I. -ansi
all: program
program: $(OBJS)
$(CC) $(CFLAGS) -o $@ $(OBJS)
... (3 Replies)
Can someone explain the correlation between how sar names the disk drives and how the rest of the OS names the disk drives?
sar lists my disk drives as sd0, sd1, sd2, etc.....
while format lists my disk drives as c1t0d0, c1t1d0, c1t2d0,etc...
And also why sar shows 8 disks but format... (2 Replies)
I stumbled upon this thread and one aspect of it got me thinking. As i am building a small Linux network right now for a friend i would like to hear your opinion on this.
I'd like to respectfully disagree. I think the Linux habit of disabling root login per default is wrong (not entirely... (6 Replies)
I'm trying to send the file list as parameter to another job and execute it.
But the loop doesn't work, the inner job is running only once and not twice as expected
for filelist in $(ls -rt *.txt | tail -2)
do
echo $filelist
export filelist
cmd="$Program -config $configfile -autoexec... (11 Replies)
We have several dozen Redhat 5, 6 and 7 servers that are running Oracle databases. On some databases we are using automatic memory management, which uses shared memory. On other databases we are use manual memory management, which does not use shared memory.
When I see that a server is swapping... (2 Replies)
Discussion started by: gandolf989
2 Replies
LEARN ABOUT OPENSOLARIS
utmpx
utmpx.h(3HEAD) Headers utmpx.h(3HEAD)NAME
utmpx.h, utmpx - user accounting database definitions
SYNOPSIS
#include <utmpx.h>
DESCRIPTION
The <utmpx.h> header defines the utmpx structure, which includes the following members:
char ut_user[]; /* user login name */
char ut_id[]; /* unspecified initialization */
/* process identifier */
char ut_line[]; /* device name */
pid_t ut_pid; /* process ID */
short ut_type; /* type of entry */
for X/Open compilation environments:
struct ut_exit_status ut_exit; /* process termination/exit status*/
for all other compilation environments:
struct exit_status ut_exit; /* process termination/exit status*/
struct timeval ut_tv; /* time entry was made */
int ut_session; /* session ID, used for windowing */
short ut_syslen; /* significant length of ut_host */
/* including terminating null */
char ut_host[]; /* remote host name */
The pid_t type is defined through typedef as described in <sys/types.h>.
The timeval structure is defined as described in <sys/time.h>.
Inclusion of the <utmpx.h> header can also make visible all symbols from <sys/time.h>.
The following symbolic constants are defined as possible values for the ut_type member of the utmpx structure:
EMPTY No valid user accounting information.
BOOT_TIME Identifies time of system boot.
OLD_TIME Identifies time when system clock changed.
NEW_TIME Identifies time after system clock changed.
USER_PROCESS Identifies a process.
INIT_PROCESS Identifies a process spawned by the init process.
LOGIN_PROCESS Identifies the session leader of a logged-in user.
DEAD_PROCESS Identifies a session leader who has exited.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
SEE ALSO endutxent(3C), time.h(3HEAD), types.h(3HEAD), attributes(5), standards(5)SunOS 5.11 16 Apr 2007 utmpx.h(3HEAD)
09-27-2008
<datatype> *)0 - this means regardless of the underlying architecture