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Help with awk Print Substr

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# 1  
Old 02-23-2013
Help with awk Print Substr
Can someone explain to me exactly how it work. I have a line from a script here,

Code:
Processed=$(cat logcheck.txt | /bin/awk '{print substr($19,0,5)}'| sed -e 's/\[//g' | sed -e 's/\].*//g')

This is what is in the logcheck.txt,


Code:
[30376] 2013-02-23 10:00:41 DOW=7 HOUR=10:00 WK=4 DOM=23 MON=2 - Total [98], Disabled [0], Skipped [0], Failed [0], Processed [98]

Please explain the $19, 0, 5.

I'm assuming the $19 is because it's in the 19th position counting left to right? What about the 0 and 5?
Last edited by Scrutinizer; 02-24-2013 at 04:07 AM.. Reason: code tags
# 2  
Old 02-23-2013
How it works...
Well, you are correct in stating that $19 is the 19th string. This is what I get with your original code...
Code:
echo '[30376] 2013-02-23 10:00:41 DOW=7 HOUR=10:00 WK=4 DOM=23 MON=2 - 
Total [98], Disabled [0], Skipped [0], Failed [0], Processed [98]' | awk '{print substr($19,0,5)}'| sed -e 's/\[//g' | sed -e 's/\].*//g'

yields
Code:
98

Note that a modification of the awk statement precludes the need for the last two sed statements..
Code:
echo '[30376] 2013-02-23 10:00:41 DOW=7 HOUR=10:00 WK=4 DOM=23 MON=2
 - Total [98], Disabled [0], Skipped [0], Failed [0], Processed [98]' | awk '{print substr($19,2,2)}'

also yields
Code:
98

substr takes [string], [position in the string to begin processing],[number of characters to return].

Because we are running awk $19 is the variable automatically assigned to the nineteenth
position.
It should be noted that my second example is not ALWAYS an adequate substitute for the original statement, because sometimes [98] may be [108], in which case the second would have returned 10, or [1] in which case the second statement would have returned 1].

Hope that helps.Smilie
This User Gave Thanks to MattyV For This Post:
scj2012
# 3  
Old 02-23-2013
Matt,

From your 108 example

Code:
awk '{print substr($19,2,2)}'

I see how you get 10. How do you get [1] and 1]. Also what meant by second statement?
Last edited by Scrutinizer; 02-24-2013 at 04:09 AM.. Reason: code tags
# 4  
Old 02-23-2013
If you just want to get at the number in the last field between the square brackets you can use either of these awks...
Code:
cat file
[30376] 2013-02-23 10:00:41 DOW=7 HOUR=10:00 WK=4 DOM=23 MON=2 - Total [98], Disabled [0], Skipped [0], Failed [0], Processed [98]

awk -F"[[]|[]]" '{print $(NF-1)}' file

awk '{gsub("[[]|[]]","",$19);print $19}' file

# 5  
Old 02-23-2013
Set opening & closing square brackets [] as field separators and extract the values inside it:
Code:
awk -F'[][]' '{ print $2, $4, $6, $8, $10, $12 }' logcheck.txt
30376 98 0 0 0 98

# 6  
Old 02-23-2013
Quote:
Originally Posted by scj2012
Matt,

From your 108 example

awk '{print substr($19,2,2)}'
I see how you get 10. How do you get [1] and 1].
So what I meant was that if the stock value was 1 dollar, the 19th string would contain "[1]" substr [1],2,2 would result in "1]"
Quote:
Also what meant by second statement?
I meant the alternative awk statement I wrote using substr $19,2,2 instead of your original statement substr $19,2,5 | sed...
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