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for loop with whole line using cat

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Top Forums Shell Programming and Scripting for loop with whole line using cat
# 8  
Old 08-02-2012
Quote:
Originally Posted by yanglei_fage
what does '1' here mean, is there a man page?
The 1, either by itself or after an outer code-block, is an implied 'print' statement. Whenever that expression is true, it prints the current line buffer. 1 is always true, so it always prints. The expression can be more complicated than that however.

This means awk '1' is equivalent to cat, awk '/asdf/' would be equivalent to grep asdf, awk '/asdf/ && !/qwerty/' would be equivalent to grep asdf | grep -v qwerty, etc, etc. You can make the expressions as complicated as you want, even including variables and the like, allowing you to reduce long pipe chains into one awk statement, or easily do complicated things that would be bothersome or impossible in grep or sed.

You can check for the presence of a man page via 'man awk'. The linux version of the manual page is quite good I've found.
# 9  
Old 08-02-2012
it is working but ima not able to print with variable
Code:
for f in `cat /home/pa039410/switch-ip/all-switch-ip.txt`
do
plink -ssh -v 123@$f -pw 456 switchshow |grep No_Light > /home/pa039410/switch-ip/switchshow-nolight.txt
plink -ssh -v 123@$f -pw 456 switchshow |grep -i online > /home/pa039410/switch-ip/switchshow-online.txt
awk '{print "$f" "," $0}' /home/pa039410/switch-ip/switchshow-nolight.txt >> /home/pa039410/switch-ip/switchshow-all-withname.txt
awk '{print "$f" "," $0}' /home/pa039410/switch-ip/switchshow-online.txt >> /home/pa039410/switch-ip/switchshow-all-withname.txt 
done

Now iam getting output

Quote:

$f, 2 1 2 040200 id N8 Online F-Port 50:00:09:74:08:1b:b9:10
$f, 3 1 3 040300 id N4 Online F-Port 50:06:04:8c:52:a9:a6:d2
$f, 4 1 4 040400 id N4 Online F-Port 50:06:04:8c:52:a9:a6:c6
$f, 5 1 5 040500 id N4 Online F-Port 50:06:01:60:3b:20:20:60
$f, 6 1 6 040600 id N4 Online F-Port 21:00:00:1b:32:10:23:13
$f, 7 1 7 040700 id N4 Online F-Port 21:00:00:1b:32:11:eb:70
$f, 8 1 8 040800 id N4 Online F-Port 21:00:00:1b:32:89:4e:c6
$f, 9 1 9 040900 id N4 Online F-Port 21:00:00:1b:32:9f:ca:26
$f, 10 1 10 040a00 id N2 Online F-Port 21:00:00:e0:8b:06:40:bf
# 10  
Old 08-02-2012
Variables do not work inside single quotes. Neither does awk share variables with the the shell.

The best way to put a variable into awk is like

awk '{print VAR "," $0}' VAR="$f" filename
# 11  
Old 08-02-2012
There are many fundamental mistakes in your script. See useless use of backticks for starters. Also, you don't need to reopen the same file 99,000 times to print 99,000 things. You don't need to ssh into a host twice to run two commands, either.

You shouldn't need plink on UNIX, either.
# 12  
Old 08-02-2012
Quote:
Originally Posted by itkamaraj
Code:
$ sed 's/^/10.0.0.1,/' input.txt
10.0.0.1,136 1 24 048800 id N4 No_Light
10.0.0.1,137 1 25 048900 id N4 No_Light
10.0.0.1,140 1 28 048c00 id N4 No_Light
10.0.0.1,262 1 38 048e80 id N4 No_Light
10.0.0.1,263 1 39 048f80 id N4 No_Light
10.0.0.1,20 2 4 041400 id N4 No_Light

---------- Post updated at 09:12 PM ---------- Previous update was at 09:11 PM ----------



awk evaluates the 1 as true and the prints the entire line by default, including a newline.
we can use below directly, why we have "1" usage, can you give a good example for this usage?
Code:
awk '$0="10.0.0.1,"$0' test.txt

# 13  
Old 08-02-2012
You are still using that syntax, you just don't know it. Like C, its okay to have an = inside an expression.

Your expression is $0="10.0.0.1,"$0

If the result is anything except 0 or "", that will be considered true, and cause the line to be printed.
# 14  
Old 08-02-2012
Instead of connecting to the remote machine twice, why not redirect output locally, then process it?
You separate into switchshow-nolight.txt and switchshow-online.txt but then merge them. Do you need these two files or just the final output?

Code:
while read host; do
	plink -ssh -v 123@"$host" -pw 456 switchshow | awk -v "host=$host" '
		index($0,"No_Light") { print host "," $0 > "/home/pa039410/switch-ip/switchshow-nolight.txt"; print }
		index(tolower($0),"online") { print host "," $0 > "/home/pa039410/switch-ip/switchshow-online.txt"; print }' > /home/pa039410/switch-ip/switchshow-all-withname.txt
done < /home/pa039410/switch-ip/all-switch-ip.txt
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