topic Re: scripting question in Operating System - HP-UX

scripting question

soji — Wed, 12 Mar 2003 14:31:40 GMT

Hi experts,
Im trying to write a script either in awk or in ksh to read in a text file with a format like shown below:
......start....
sht 2 3 4
trc 4 5 5
trc 3 3 2
trc 2 3 4
trc 3 4 1
trc 1 3 6
trc 3 3 5
trc 4 3 1
trc 2 3 5
sht 1 6 3
trc 4 5 5
trc 3 3 2
trc 2 3 4
trc 3 4 1
trc 1 3 6
trc 3 3 5
trc 4 3 1
trc 2 3 5
.........end.........
It is a really long file with similar format. All I want to do is to read in the file and print the line that starts with "sht" and every fourth line that starts with "trc"

Could somebody help me please

Thanks in advance

Re: scripting question

Robin Wakefield — Wed, 12 Mar 2003 14:36:01 GMT

Hi,

awk '/^sht/ || (NR%4 == 0 && /^trc/){print}' filename

should do the trick (if I interpret the trc requirement correctly).

rgds, Robin

Re: scripting question

Stefan Farrelly — Wed, 12 Mar 2003 14:41:26 GMT

let x=0
cat t|while true
do
read A B C D
[ "$A" = "" ] && exit
[ "$A" = "sht" ] && echo $A $B $C $D
if [ "$A" = "trc" ]
then
let x=$x+1
if [ $x -eq 4 ]
then
echo $A $B $C $D
let x=0
fi
fi
done

where t (on 2nd line in cat t) is the name of the input file with all your data in.

Re: scripting question

soji — Wed, 12 Mar 2003 14:44:11 GMT

Thanks for the quick reply.
It is very close.

I actually want to print every fourth occurence of lines begining with "trc"

Thanks a lot again

Re: scripting question

Robin Wakefield — Wed, 12 Mar 2003 14:47:25 GMT

OK, well try:

awk '/^sht/{print}/^trc/{count++;if (count==4){print;count=0}}' file

this resets the counter after 4 occurrences of trc at the beginning of the line.

rgds, Robin

Re: scripting question

Steve Steel — Wed, 12 Mar 2003 14:56:40 GMT

Hi

file=$1
typeset -i x=1
cat $file|while read a b c d
do
case $a in
sht) echo $a $b $c $d ;;
trc) if [ "$x" -eq "4" ]
then
let x=1
echo $a $b $c $d
else
typeset -i x=$x+1
fi ;;
esac
done

Steve Steel

Re: scripting question

H.Merijn Brand (procura — Wed, 12 Mar 2003 15:28:40 GMT

# perl -ne'/^sht/||(/^trc/&&++$t%4==0)and print' log
sht 2 3 4
trc 3 4 1
trc 2 3 5
sht 1 6 3
trc 3 4 1
trc 2 3 5

Enjoy, have FUN! H.Merijn

Re: scripting question

soji — Fri, 14 Mar 2003 05:31:20 GMT

Thank you All for the replies and help...Especially Robin who was quick...I chose you second solution. By the way what does the NR%4 do in your first solution what does modulus do in awk?

thanks

Re: scripting question

Yogeeraj_1 — Fri, 14 Mar 2003 06:09:17 GMT

hi,
FYI:

x % y
Remainder. The quotient is rounded toward zero to an integer, multiplied by y and this result is subtracted from x. This operation is sometimes known as "trunc-mod." The following relation always holds:
b * int(a / b) + (a % b) == a

One possibly undesirable effect of this definition of remainder is that x % y is negative if x is negative. Thus,
-17 % 8 = -1

hth
Yogeeraj