Can someone explain what these arguments mean?


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Can someone explain what these arguments mean?
# 1  
Old 12-17-2012
Can someone explain what these arguments mean?

Hi folks,

I am betting this is a very simple thing, but I admit i don't know the proper terms to search it out correctly.

I am self-learning at work.
I've come on a section of code in a script:
Code:
/usr/sbin/ping $dev 5 2 2>&1 | /usr/xpg4/bin/egrep -s "unknown host|no answer"

What I can't figure out(or search out) is what the arguments "5 2 2>&1" are doing??

I thought it was setting 2 '5 byte messages' with a time to live of 2...something.
But I can not find any data to support that or otherwise explain what's going on here.

So thanks to anyone who can explain this.

Marc
# 2  
Old 12-17-2012
Check man ping on that system (I'm guessing it is Solaris) to get explanation of 5 2. 2>&1 is a redirection technique, allowing to "merge" standard error messages into standard output stream.
This User Gave Thanks to bartus11 For This Post:
# 3  
Old 12-17-2012
2>&1 directs standard error to standard output.

For the "$dev 2 5" arguments you will need to read the manual page ("man ping") for your system. My system does not support that usage.

It would appear that "$dev" is the hostname, and "2 5" possibly the timeout and count.

Check the man page.
This User Gave Thanks to Scott For This Post:
# 4  
Old 12-17-2012
The ping command on AIX uses those two parameters.

From the man page:

Code:
5
PacketSize
Specifies the number of data bytes to be sent. The default is 56, which translates into 64 ICMP data bytes when combined with the 8 bytes of ICMP header data. This parameter is included for compatibility with previous versions of the ping command.

2
Count
Specifies the number of echo requests to be sent (and received). This parameter is included for compatibility with previous versions of the ping command.

Example: ping server 5 2
PING server (xxx.xxx.xxx.xxx): 5 data bytes
13 bytes from xxx.xxx.xxx.xxx: icmp_seq=0 ttl=64
13 bytes from xxx.xxx.xxx.xxx: icmp_seq=1 ttl=64

--- server ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss

This User Gave Thanks to in2nix4life For This Post:
# 5  
Old 12-17-2012
Thank you all for giving me the answer here! I had not tried this on an AIX box. Only a virtual linux box and a Solaris server I have access too.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

How I can explain this?

Hi friends! I'm learning UNIX and I have a small question. Working with Shell, i put the name of one executable (in c language) + one number and it says this: $ gcc misterioso_4.c $ ./misterioso_4 6 got: , I can not find an answer in the manual because I havent applied any variable.... (5 Replies)
Discussion started by: dakota
5 Replies

2. Shell Programming and Scripting

Can someone explain this for me?

Can someone do me a favour and explain the following for me: ((r=$RANDOM%$n+1)) I know what $RANDOM does but what is % sign and what does it do with %$n+1? (2 Replies)
Discussion started by: bashily
2 Replies

3. Shell Programming and Scripting

anyone can explain this?

why the case 2 will happen ? , ' should stop the history substitution ,shouldn't it? case 1 # echo "123"|sed '/123/!d' 123 case 2 # echo "123 > 456 > 1 > "|sed '/123/!d' -bash: !d': event not found case 3 # echo "123 > 456 > 12 > "|sed '/123/'\!d 123 # bash --version (1 Reply)
Discussion started by: justlooks
1 Replies

4. Shell Programming and Scripting

grep with two arguments to arguments to surch for

Hello, is it possible to give grep two documents to surche for? like grep "test" /home/one.txt AND /home/two.txt ? thanks (1 Reply)
Discussion started by: Cybertron
1 Replies

5. Shell Programming and Scripting

can any one explain this example

hi all i have an example i want one help me to understand cause i tried to test it but almost fail and i don't know how can i solve this problem " the main idea to read from two files and replace something from one to another " but i don't understand why it fail all time $ cat main.txt... (4 Replies)
Discussion started by: maxim42
4 Replies

6. UNIX for Dummies Questions & Answers

Please explain this

if then echo "Syntax: $0 <sid> <COLD/HOT> <DEST>" exit fi if --------------what does this mean??? echo "Syntax: $0 <sid> <COLD/HOT> <DEST>"---pls explain this as well (2 Replies)
Discussion started by: appsdba.nitin
2 Replies

7. AIX

can anyone explain this?

this is the mksys b script.... can anyone explain .. what # and 1 in if condition this is the first line of the script... it is not from middle of the script.... if then echo "Not enough parameters, need a client name for mksysb" Usage="Usage: $0 <client name>" ... (2 Replies)
Discussion started by: honeym210
2 Replies

8. Shell Programming and Scripting

please explain the below

could u please convert the below statement to shell script ---------- logdir=/smp/dyn/logfiles/cpm/pgm/pgIm $logdir = $logdir ."/pgIm${toDate}*"; ---- could u please explain the below clearly grep -i adding $logdir | grep -iv equation | awk '{print \$NF}' | sort -u | sed -e... (1 Reply)
Discussion started by: mail2sant
1 Replies

9. Shell Programming and Scripting

Please can any one explain this ${0##/}

I did not understand what is ${0##/} PGM=${0##/} TMP=/tmp/${PGM}.$$ Please explain me. (2 Replies)
Discussion started by: gadege
2 Replies

10. Shell Programming and Scripting

please explain this

zsh 4.3.4% cat file ACFCFACCACARCSHFARCVJVASTVAJFTVAJVGHBAJ zsh 4.3.4% cat file1 A C F R zsh 4.3.4% <file1 while read;do printf "%s=%d\n" "$REPLY" "${#$(<file)//}";done A=9 C=7 F=4 R=2 That was the previous post. But , can anybody can explain me in detail about this line zsh... (2 Replies)
Discussion started by: dummy_needhelp
2 Replies
Login or Register to Ask a Question