02-25-2013
Disclaimer: I have never used AIX. Everything I say below is based on the OP's statement that /dev/null is a regular file.
Quote:
Originally Posted by
Corona688
Take my advice with a grain of salt since I'm not an AIX expert, but: Having a /dev/null that is not a character device could be a big problem, yes! Things might create huge files in it, expecting them to go into the bit bucket, but actually ending up on disk instead... Some memory mapping things might not work right... etc.
Although a less common scenario, there are times when using /dev/null for reading is useful. One example that comes to mind is with grep, to force its output to include filenames, you may explicitly list /dev/null in a find -exec predicate or an xargs invocation, to ensure that grep is never called with a single file argument. If /dev/null does not yield nothing but EOF ... woe.
Regards,
Alister
Last edited by alister; 02-25-2013 at 02:26 PM..
This User Gave Thanks to alister For This Post:
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
hello all,
I am working in a Hpux 11.0 64 bit environment. I am not sure if a third party software is doing this or not, but the admin to this server says it is not a server issue as he has check and double check logs and crons to verify this issue. My problem, is that every now and then, once... (4 Replies)
Discussion started by: oott
4 Replies
2. UNIX for Dummies Questions & Answers
First of all, hello there cOmMuNity ! :cool:
Well, I've got two basic questions:
1) In how many ways it's possible to create a file ?
I know one manner using "touch", other typing something like echo "" > file ...
The fact is that I need to overwrite the file if it exists, and touch... (8 Replies)
Discussion started by: 435 Gavea
8 Replies
3. UNIX for Advanced & Expert Users
Hi,
Q1-What does
nroff -ms > /dev/null
Q2- What does mean -A under STAT column :
ps aux |head -20
UTIL PID %CPU %MEM SZ RSS TTY STAT STIME TIME COMMAND
root 516 93,0 0,0 12 12 - A 04 nov 3906:51 wait
Thank you. (4 Replies)
Discussion started by: big123456
4 Replies
4. Solaris
Please help urgently.
I need to setup up some sort of service on a solaris server on a port.
I dont need it do anything special, anything that is sent to this port from an external server should be dump to /dev/null or a flat file..
Can you help urgently? (1 Reply)
Discussion started by: frustrated1
1 Replies
5. UNIX for Advanced & Expert Users
when i write the following two statements :
cp /dev/NULL /clocal/mqbrkrs/user/mqsiadm/sanjay/dspmq_temp
cat /dev/NULL > /clocal/mqbrkrs/user/mqsiadm/sanjay/dspmq_temp
its gives me errors like :
cp: /dev/NULL: A file or directory in the path name does not exist.
cat : /dev/NULL can't open... (2 Replies)
Discussion started by: varungupta
2 Replies
6. Solaris
Hi, Anyone can help
My solaris 8 system has the following
/dev/null , /dev/tty and /dev/console
All permission are lrwxrwxrwx
Can this be change to a non-world write ??
any impact ?? (12 Replies)
Discussion started by: civic2005
12 Replies
7. UNIX for Dummies Questions & Answers
How are these two different? They both prevent output and error from being displayed. I don't see the use of the "&"
echo "hello" > /dev/null 2>&1
echo "hello" > /dev/null 2>1 (3 Replies)
Discussion started by: glev2005
3 Replies
8. UNIX for Dummies Questions & Answers
Hi,
I'm currently using the following command to wipe clean a log file which can't be straight out RM'd:
cat /dev/null > server.log
I'm building this into a script and I'm current working on a command to run on each machine to do this automatically however I have multiple files so I need... (11 Replies)
Discussion started by: Deehem
11 Replies
9. Shell Programming and Scripting
I apologize if this question has been answered else where or is too elementary.
I ran across a KSH script (long unimportant story) that does this:
if ; then
CAS_SRC_LOG="/var/log/cas_src.log 2>&1"
else
CAS_SRC_LOG="/dev/null 2>&1"
fithen does this:
/usr/bin/echo "heartbeat:... (5 Replies)
Discussion started by: jbmorrisonjr
5 Replies
10. AIX
Hello
Can I just remove/delete flile ?
rw-r--r-- 1 root system 2385088512 Jun 30 21:25 /dev/null 2>&1
size of this flile is 2274.75 m and fill up my filesystem:
Filesystem MB blocks Used Free %Used Mounted on
/dev/hd4 2560.00 2558.59 1.41 100% / (10 Replies)
Discussion started by: primo102
10 Replies
LEARN ABOUT OSX
mkdevmaps
mkdevmaps(1M) System Administration Commands mkdevmaps(1M)
NAME
mkdevmaps - make device_maps entries
SYNOPSIS
/usr/sbin/mkdevmaps
DESCRIPTION
The mkdevmaps command writes to standard out a set of device_maps(4) entries describing the system's frame buffer, audio, and removable
media devices.
The mkdevmaps command is used by the init.d(4) scripts to create or update the /etc/security/device_maps file.
Entries are generated based on the device special files found in /dev. For the different categories of devices, the mkdevmaps command
checks for the following files under /dev:
audio /dev/audio, /dev/audioctl, /dev/sound/...
tape /dev/rst*, /dev/nrst*, /dev/rmt/...
floppy /dev/diskette, /dev/fd*, /dev/rdiskette, /dev/rfd*
removable disk /dev/dsk/c0t?d0s?, /dev/rdsk/c0t?d0s?
frame buffer /dev/fb
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
|Interface Stability |Obsolete |
+-----------------------------+-----------------------------+
SEE ALSO
allocate(1), bsmconv(1M), attributes(5)
NOTES
mkdevmaps might not be supported in a future release of the Solaris operating system.
SunOS 5.10 8 Oct 2003 mkdevmaps(1M)