UNIX for Dummies Questions & Answers

Hi guys im from argentina, i`m trying to pass the variable b yo the awk, how can i do that?..i am trying that awk print the month that is b

a=`date +%m`
mesn=`expr $a - 1`

case "$mesn" in
1)
b="Jan"
;;
2)
b="Feb"
;;
3)
b="Mar"
;;
4)
b="Abr"
;;
5)
b="May"
;;
6)
b="Jun"

;;
7)
b="Jul"
;;
8)
b="Aug"
;;
9)
b="Sep"
;;
10)
b="Oct"
;;
11)
b="Nov"
;;
12)
b="Dec"
;;
esac



last -a |grep "$b"|nawk 'BEGIN {i=0;h=b}
{print h}
$4 ~ /h/ {print $0;i=1}
/system boot/ && $5 ~ /h/ {print $0;i=1}
$4!~ /h/ {if(i==1) exit;}

Something like:

Code:

nawk -v var="$b" '{$4==var{do something......}'

Regards

You can try something like this :-

set -A Months -- 0 JANUARY FEBRUARY MARCH APRIL MAY JUNE JUL AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER

# The above command will create an array called Months and will set the
# months as its value

a=`date +%m`
mesn=`expr $a - 1`

# Now in order to retrieve the value of the desired month do the following :

Value=${Months[$mesn]}

Hope that helps...

Cheers,
Kunal

Thank you all for you help, i`m going to explain what i have to do, i need to create a script for a client that list the people than conect to the computer but not this month , a month behind (example where are in jul i need to see the last of jun), I dont understand kunal, is killing me this script
a=`date +%m`
mesn=`expr $a - 1`

case "$mesn" in
1)
b="Jan"
;;
2)
b="Feb"
;;
3)
b="Mar"
;;
4)
b="Abr"
;;
5)
b="May"
;;
6)
b="Jun"

;;
7)
b="Jul"
;;
8)
b="Aug"
;;
9)
b="Sep"
;;
10)
b="Oct"
;;
11)
b="Nov"
;;
12)
b="Dec"
;;
esac
grep $b|last -a|nawk -v var="$b" 'BEGIN {i=0;$h==var}

$4 ~ /h/ {print $0;i=1}
/system boot/ && $5 ~ /h/ {print $0;i=1}
$4!~ /h/ {if(i==1) exit;}

'
"prueba2.sh" 53 lines, 1100 characters
u2-8# sh prueba2.sh
nawk: illegal field $()
source line number 1

THANK YOU

.. if your goal is to just to print the last month, here's another way using an array:

Code:

#!/usr/bin/ksh

A=$(date +%m)

set -A YEAR 0 0 JAN FEB MAR APR MAY JUN JUL AGO SEP OCT NOV DEC

if (( ${A} == 1 )); then
   B=DEC
else
   B=${YEAR[${A}]}
fi
echo ${B}

Need to add since something since I didn't see your last post.

Code:

grep $b | last -a|nawk -v var="$b" 'BEGIN {i=0;$h==var}

The bolded text, you are missing the file (or output) you are grepping $b from.

yes system shock , but mi problem is i need to pass that month to the nawk sentences to make the comparation, and the nawk use the last -a to make the comparation. Thank for your time

..yeah, but if you start a command string with the wrong syntax, you are never going to get the output you are expecting. In this case, grep must grep the string from something, being a file or an output.

I take it is a log file that's logging the user activity, and this log file has a date stamp that includes the month. If that is the case, then the command should be:

Code:

 grep $b logfile

... then you can pipe the output of that command to last, then awk.

tNow, I think you are making things a little more complicated than they need to be.
Why don't you post a sample output from the log file and show us what you are trying to compare?

BTW, use code tags. They make your output and code more readable.