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awk substr issue

 
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# 1  
Old 05-19-2014
awk substr issue
Hi,

I am trying to print last few characters of a string but unable to get the correct output through awk substr.

The length of the string and the number of characters to be printed varies day to day.

For example,To print 1234 from abcdef1234, i will be given 2 strings,string1(for example abcdef1234) and another string2 (for example nnnn) whose length is the number of characters i need to print from reverse of string1.


My code is:

Code:
# test.ksh 
#!/bin/ksh
file2=$2
file=$1
echo file=$file
len=`expr ${#file2}`
final_string=`echo $file | awk '{print substr($0,length($file)-length($file2),length($file2))}'`
echo $final_string



Execution: ksh -x test.ksh 1234567890987 nnnn
Output:
Code:
+ file2=nnnn
 + file=1234567890987
 + echo file=1234567890987
 file=1234567890987
 + + expr 4
 len=4
 + + awk {print substr($0,length($file)-length($file2),length($file2))}
 + echo 1234567890987
 final_string=1234567890987
 + echo 1234567890987
 1234567890987



Any help on this scenaio?
# 2  
Old 05-19-2014
change the awk line to below
Code:
awk -v file="${file}" -v file2="${file2}" '{print substr($0,length(file)-length(file2),length(file2))}'

# 3  
Old 05-19-2014
Try
Code:
echo "$file" | awk -vf2="$file2" '{ print substr ($0, length ($0) - length(f2) + 1) }'

# 4  
Old 05-19-2014
Hi,

I rewrote the code as below:
Code:
#!/bin/ksh

file2=$2
file=$1
echo file=$file
echo file2=$file2
final_string=`echo $file | awk -v file="${file}" -v file2="${file2}" '{print substr($0,length(file)-length(file2),length(file2))}'`
echo $final_string

But i am getting an error:

Code:
$ksh -x test.ksh 1234567890987 nnnn
+ file2=nnnn
+ file=1234567890987
+ echo file=1234567890987
file=1234567890987
+ echo file2=nnnn
file2=nnnn
+ + awk -v file=1234567890987 -v file2=nnnn {print substr($0,length(file)-length(file2),length(file2))}
+ echo 1234567890987
awk: syntax error near line 1
awk: bailing out near line 1
final_string=
+ echo

# 5  
Old 05-20-2014
Quoting Don Cragun:
Quote:
As always, if you want to run this on a Solaris/SunOS system, change awk to /usr/xpg4/bin/awk , /usr/xpg6/bin/awk , or nawk .
This User Gave Thanks to RudiC For This Post:
Bobby_2000
 
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