topic Re: Shell program in Operating System - HP-UX

Shell program

Vande Matram — Sat, 22 Jun 2002 14:41:02 GMT

Hi,
what I need to do is this.
1. Read a file called Mar28.csv, the file contains only two filed. For example,
Citi Bank Payment,-30
Deposit,1349.2

2. If the second field contains a negative amount then I need to change it to
Citi Bank Payment,,-30
else if the second field is a positive number then I need to change it to
Deposit,1349.2,
I am trying to do this using shell programming.
I have been going round and round in circle for a while now without much success and if someone is kind enough to show it to me by giving an example I would really appreciate it.

Re: Shell program

Paula J Frazer-Campbell — Sat, 22 Jun 2002 14:59:31 GMT

Hi

To pick up the negative amount and add an extra , then:-

cat Mar28.csv | sed 's/,-/,,-/' >Mar28.csv-new

This will change

Citi Bank Payment,-30

to:-

Citi Bank Payment,,-30

Can you attach and example of your cvs file?

Paula

Re: Shell program

Steven Sim Kok Leong — Sat, 22 Jun 2002 15:03:09 GMT

Hi,

Off the top of my head, following is one most inefficent way which I typed in a rush (untested):

#!/sbin/sh

lineno=1
lastline=`wc -l $1|awk '{print $1}'`

while [ "$lineno" -le "$lastline" ]
do
line=`head -$lineno $1|tail -1`
if echo $line|awk -F\, '{print $2}'|grep '\-' >/dev/null
then
echo $line|awk -F\, '{print $1,",,",$2}'
else
echo $line
fi
lineno=`expr $lineno + `
done

Hope this helps. Regards.

Steven Sim Kok Leong

Re: Shell program

Steven Sim Kok Leong — Sat, 22 Jun 2002 15:06:25 GMT

Hi,

Typo in my quick draft of a script:

lineno=`expr $lineno + `

should be:

lineno=`expr $lineno + 1`

Hope this helps. Regards.

Steven Sim Kok Leong

Re: Shell program

A. Clay Stephenson — Sat, 22 Jun 2002 15:10:17 GMT

Probably the best tool for something like this is awk (or Perl). The attached bank.sh creates an awk script 'on the fly' and calls awk.

bank.sh < Mar28.csv > Newfile
STAT=$?

if ${STAT} is non-zero, bad input data was detected.

Re: Shell program

Ceesjan van Hattum — Sat, 22 Jun 2002 20:11:55 GMT

awk 'BEGIN{FS=","} {printf "%s,",$1
if ($2<0) printf ",%s\n",$2
else printf "%s,\n",$2
}' INPUTFILE

Regards,
Ceesjan

Re: Shell program

Rodney Hills — Sat, 22 Jun 2002 22:52:24 GMT

Paula's sed is the most direct. However, If you wanted to use perl, then-

perl -pie 's/[^,],-/,,-/' thefile.csv

This will make the change and put the results back into the same file. The additional feature this has over Paula's is that if you forget and run the process twice on the same file, it will leave the file in the proper format. Paula's would just keep adding commas everytime is was run.

perl... Try it.. You'll like it...

-- Rod Hills

Re: Shell program

Vande Matram — Mon, 24 Jun 2002 00:36:46 GMT

Hi guys! Thank you very much for all your help.
I appreciate your feedback very much, and so everyone gets 10 points. However, to be frank with you lot of the stuff you said, went over my head because I am just starting out learning UNIX. :-) However, I ended up using a much simpler approach using awk utility. It is so simple it is amazing :-) and makes me proud of myself!! You won't believe it but this one line did all the work for me!
awk -F',' '{if ($2 > 0) {print $2","} else {print ","$2}}' Mar28.csv
Are you surprised? Thanks guys...you all are awesome!

Re: Shell program

Vande Matram — Mon, 24 Jun 2002 01:48:35 GMT

It's too bad I can't assign myself 10 pts! ;-)

Re: Shell program

Ceesjan van Hattum — Mon, 24 Jun 2002 06:04:12 GMT

Hi Vande,
Do you see any differences between your solution and mine? It's a good thing not to assign points to yourself.
Keep dreaming...