10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Friends have the following problem
a search may not find anything which would correct example:
ls -ltr *prueba.txt | nawk '{ print $9 }' > Procesar.dat 2>/dev/null
When he finds nothing gives me the following error
ls: prueba.txt: No such file or directory
because 2> / dev / null... (4 Replies)
Discussion started by: tricampeon81
4 Replies
2. Shell Programming and Scripting
Hello All and a Happy New year to yous guys.
I'm running the below command on my AIX box and it keeps giving me the message that the file doesn't exist. I know the file don't exist, but I don't want to see the error. 2>/dev/null doesn't work.
bash-3.00$ ls -l C* | wc -l 2>/dev/null
ls:... (2 Replies)
Discussion started by: bbbngowc
2 Replies
3. 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
4. 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
5. Shell Programming and Scripting
when do you use the path /dev/null (3 Replies)
Discussion started by: webmunkey23
3 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. Shell Programming and Scripting
hello all,
In many shell scripts i found '> /dev/null' , i am not able to get this,
will any one please explain why we are using this.
thanks
sudha (2 Replies)
Discussion started by: rrs
2 Replies
8. 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
9. UNIX for Dummies Questions & Answers
Hi ,
I am importing some table from /dev/null i dont understand what is /dev/null
Sorry i am new to UNIX
sam71 (3 Replies)
Discussion started by: sam71
3 Replies
10. UNIX for Dummies Questions & Answers
Maybe it's an stupid question but remeber... I'm Junior..
I use command line to run programs, and some of them gives a lot of information when, for example, you open a window or other actions. That's really bad because my terminal gets full of unwanted messages, so I use "bin file & >/dev/null"... (1 Reply)
Discussion started by: piltrafa
1 Replies
Mirror/redirect action in tc(8) Linux Mirror/redirect action in tc(8)
NAME
mirred - mirror/redirect action
SYNOPSIS
tc ... action mirred DIRECTION ACTION [ index INDEX ] dev DEVICENAME
DIRECTION := { ingress | egress }
ACTION := { mirror | redirect }
DESCRIPTION
The mirred action allows packet mirroring (copying) or redirecting (stealing) the packet it receives. Mirroring is what is sometimes
referred to as Switch Port Analyzer (SPAN) and is commonly used to analyze and/or debug flows.
OPTIONS
ingress
egress Specify the direction in which the packet shall appear on the destination interface.
mirror
redirect
Define whether the packet should be copied (mirror) or moved (redirect) to the destination interface.
index INDEX
Assign a unique ID to this action instead of letting the kernel choose one automatically. INDEX is a 32bit unsigned integer greater
than zero.
dev DEVICENAME
Specify the network interface to redirect or mirror to.
EXAMPLES
Limit ingress bandwidth on eth0 to 1mbit/s, redirect exceeding traffic to lo for debugging purposes:
# tc qdisc add dev eth0 handle ffff: ingress
# tc filter add dev eth0 parent ffff: u32
match u32 0 0
action police rate 1mbit burst 100k conform-exceed pipe
action mirred egress redirect dev lo
Mirror all incoming ICMP packets on eth0 to a dummy interface for examination with e.g. tcpdump:
# ip link add dummy0 type dummy
# ip link set dummy0 up
# tc qdisc add dev eth0 handle ffff: ingress
# tc filter add dev eth0 parent ffff: protocol ip
u32 match ip protocol 1 0xff
action mirred egress mirror dev dummy0
Using an ifb interface, it is possible to send ingress traffic through an instance of sfq:
# modprobe ifb
# ip link set ifb0 up
# tc qdisc add dev ifb0 root sfq
# tc qdisc add dev eth0 handle ffff: ingress
# tc filter add dev eth0 parent ffff: u32
match u32 0 0
action mirred egress redirect dev ifb0
SEE ALSO
tc(8), tc-u32(8)
iproute2 11 Jan 2015 Mirror/redirect action in tc(8)