INTELLIGENT WORK FORUMS
FOR COMPUTER PROFESSIONALS

Member Login

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips now!

Talk With Other Members
Be Notified Of Responses
To Your Posts
Keyword Search
One-Click Access To Your
Favorite Forums
Automated Signatures
On Your Posts
Best Of All, It's Free!

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

LINK TO THIS FORUM!

Tek-Tips LinkedIn^® Group

Join our
LinkedIn^® Group!

Hook up with past and present colleagues and classmates quickly.

Partner With Us!

"Best Of Breed" Forums Add Stickiness To Your Site

(Download This Button Today!)

Feedback

"...This was the ONLY place that I could find information that I could use to resolve the problem. So thanks once again to member TomSark and the SQL forum!..."

More...

Geography

Where in the world do Tek-Tips members come from?

Click Here To Find Out!

Tek-Tips Shirts!

Get your
Tek-Tips Forums
SWAG here!

Home > Forums > Programmers > Languages > UNIX Scripting Forum

trouble with controlling loop in script and debugging(5)

CODE

#!/bin/sh
#--------------------------------------------
# Author: Ziggy

# Date  : January 18 2011
# RF scanning
#--------------------------------------------

# Main Variables Definition

LOGO="RF Scan Menu"
bold=`tput smso`
offbold=`tput rmso`
counter=1

#------------------------------------------------------
# MAIN MENU PROMPTS
#------------------------------------------------------
amenu="Type exit to close";

#------------------------------------------------------
#  MAIN Routine
#------------------------------------------------------

# trying to use to debug and count loop... gives error for...bracket  }
#% if ($counter > 1 ) {
#% break
#% }

mainframe () {
clear
tput cup   3 1; echo xxxxxxxxxxxxxxxxxxxxx
tput cup   4 1; echo x; tput cup 4 21; echo x
tput cup   5 1; echo xxxxxxxxxxxxxxxxxxxxx
tput cup   9 5; echo Scan Barcode
}

themenu () {
tput cup  0 4; echo "${bold} Company Name ${offbold}"
tput cup  1 5; echo "${bold} $LOGO ${offbold}\n"
tput cup  4 2; echo $amenu;
tput cup  9 0; echo $MSG

# position of field to scan into

tput cup  8 3; echo "Order: "
tput cup  10 2; echo "Scan: "

  tput cup 8 10; read ORDN

}

#------------------------------------------------------
# MAIN LOGIC
#------------------------------------------------------

#MSG=
while  true
do
  mainframe
  themenu
  tput cup 10 10; read answer

#  MSG=
  case $answer in

       exit) clear;break;;

      *)echo $ORDN $answer >> /home/zigsto/ScanTest2.txt;;

  esac

counter=$(echo "$counter +1" | bc)

#break

done
print $counter

Thanks

Ziggy

ZiggyS1 (Programmer)

20 Jan 11 12:16

I really need to understand the bracketing thing...

eg...

Syntax error at line xx : `{' is not expected.

I get that if i try to add a IF or While condition/loop I tried both

eg

CODE

i = 1
while ( i <=4 ) {
print $i
++i
}

SamBones (Programmer)

20 Jan 11 12:32

The brackets are for C programs. An "if" in the Bourne Shell would be like this...

CODE

if ( $counter > 1 )
then
break
fi

Try "man sh" for more information.

I would also recommend you use the Korn shell (ksh). It's just personal preference, but I find it does have more features and it's more forgiving (it does what you mean more often).

ZiggyS1 (Programmer)

20 Jan 11 12:49

thanks

ok I decided to experiment in this area with the if....

CODE

if ( $ORDN = "" )
then

tput cup 8 3; echo "Order: "

tput cup 8 10; read ORDN
fi

now i get this error... what does it mean? Sorry, I'm not very proficient with Unix, I know a little bit here and there.... enough to be dangerous :)

rfscan2[11]: ORDN: not found.

ZiggyS1 (Programmer)

20 Jan 11 14:13

I am using ksh btw...

I know it only said sh at the top.

also tried this but this says no matching DO

CODE

while  true
do
case $ORDN in

1)
  tput cup  8 3; echo "Order: "
  tput cup 8 10; read ORDN;;

*)
tput cup  8 3; echo "Order: "
tput cup 8 10; echo $ORDN;;

esac

arghh... I was doing so good yesterday

ZiggyS1 (Programmer)

20 Jan 11 14:42

I figured it out. I will post as soon as I clean it up.

ZiggyS1 (Programmer)

20 Jan 11 15:43

here is my solution.... works great..... thanks for you input, got me thinking in the right direction.... most of my problem is not being able to spot my errors quickly.

CODE

#!/bin/sh
#--------------------------------------------
# Author: Ziggy S

# Date  : January 18 2011
# RF scanning
#--------------------------------------------

# Main Variables Definition

LOGO="RF Scan Menu"
bold=`tput smso`
offbold=`tput rmso`
counter=1
counterb=1
ORDN=1
stmp=`date`

#------------------------------------------------------
# MAIN MENU PROMPTS
#------------------------------------------------------
amenu="Type exit to close";

#------------------------------------------------------
#  MAIN Routine
#------------------------------------------------------

  mainframe () {
        clear
        tput cup   3 1; echo xxxxxxxxxxxxxxxxxxxxx
        tput cup   4 1; echo x; tput cup 4 21; echo x
        tput cup   5 1; echo xxxxxxxxxxxxxxxxxxxxx
        tput cup   9 5; echo Scan Barcode
               }

    themenu () {
        tput cup  0 4; echo "${bold} Company ${offbold}"
        tput cup  1 5; echo "${bold} $LOGO ${offbold}\n"
        tput cup  4 2; echo $amenu;
        tput cup  9 0; echo $MSG

    # position of field to scan into

    tput cup  10 2; echo "Scan: "

# used to either "Read" the order number or display it if it was scanned once
# when appending to file (at end of code), the order number needs to remain static for the session

                case $ORDN in

            1)
                tput cup  8 3; echo "Order: "
                tput cup 8 10; read ORDN;;

            *)
                tput cup  8 3; echo "Order: "
                tput cup 8 10; echo $ORDN;;

        esac

}

#------------------------------------------------------
# MAIN LOGIC
#------------------------------------------------------

        while  true
        do

        # goes to menu routines
          mainframe
          themenu

          tput cup 10 10; read answer

              case $answer in

           exit) clear;break;;
           # Appends scans to file
          *)echo $ORDN","$answer","$stmp >> /home/zigsto/ScanTest2.txt;;

        esac

done

stefanwagner (Programmer)

21 Jan 11 2:24

You should replace backticks with $()-constructs:

CODE

bold=`tput smso`
bold=$(tput smso)

Don't use clear - it deletes what the user produced on his screen. I recommend reading 'the art of unix programming': http://www.catb.org/~esr/writings/taoup/html/

don't visit my homepage: http://home.arcor.de/hirnstrom/minis/index.html

feherke (Programmer)

21 Jan 11 4:07

Hi

Just to clean up a mistake.

Quote (SamBones):
if ( $counter > 1 )

Quote (Ziggy):
if ( $ORDN = "" )

Syntactically correct, but probably not what you want.

Quote (man ksh):
((expression ))
The expression is evaluated using the rules for arithmetic evaluation described below. If the value of the arithmetic expression is non-zero, the exit status is 0, otherwise the exit status is 1.

(list )
Execute list in a separate environment. Note, that if two adjacent open parentheses are needed for nesting, a space must be inserted to avoid evaluation as an arithmetic command as described above.

SamBone's code will execute the command $counter and redirect its output to the file 1. If $counter has no value, an empty file with name 1 will be created.

Ziggy's code will execute the command $ORDN and pass = "" to it as parameters. If $ORDN has no value, will try to use = as command and will fail.

But as (( )) is for numeric evaluation only and if I understand correctly $ORDN may contain any string, better use [[ ]] for the test :

CODE

if [[ "$ORDN" = "" ]]
then
tput cup 8 3; echo "Order: "
tput cup 8 10; read ORDN
fi

Feherke.
http://free.rootshell.be/~feherke/

ZiggyS1 (Programmer)

21 Jan 11 9:03

thanks...feherke, stefanwagner and Sam

I'm reading up on the proper syntax, I have a couple of Unix books by Dale Dougherty/Arnold Robbins... so I'll pay attention to your comments.

One question, would the best practice be for me to create separate programs to "Call" from the main to do different things like other menus or functions

SamBones (Programmer)

21 Jan 11 12:46

You might be using the Korn Shell, but your script is using the Bourne Shell if is has this line as the first line...

CODE

#!/bin/sh

That is called the "she-bang line" and forces the script to use that program, whatever it is. It is the only comment in a script that actually gets executed. Change it to this...

CODE

#!/bin/ksh

ZiggyS1 (Programmer)

21 Jan 11 13:06

thanks Sam, I thought the comment was good enough...changed it.

another question...

works...
if [[ "$ORDN" = "" ]]

does not work...

if [[ "$ORDN" <> "" ]]

how do I show not equal to blank

ZiggyS1 (Programmer)

21 Jan 11 13:14

ahh ok I found it...

if [[ "$ORDN" -ne "" ]]

ZiggyS1 (Programmer)

21 Jan 11 13:59

ok, another glitch...

using..
if [[ "$ORDN" -ne ""]]

seems to not allow me to use characters, which makes sense as noted by feherke... but using braces doesn't work right as it gets stuck in a loop... this works perfect fro numbers alone?

error...

The specified number is not valid for this command

ZiggyS1 (Programmer)

21 Jan 11 14:36

the mor eI read the more I learn :)

if [[ "$ORDN" != "" ]]

works for string

p5wizard (IS/IT--Management)

21 Jan 11 14:46

> the more I read the more I learn :)

Well, that's the idea really

HTH,

p5wizard

SamBones (Programmer)

24 Jan 11 13:06

The Korn Shell book I like best is on Addison Wesley by Anatole Olczak. It presents it in a good order and goes into just enough depth on each topic. I've recommended it to a lot of people and a lot of people swear by it now.

ZiggyS1 (Programmer)

24 Jan 11 14:05

thanks Sam, I saved it to my Blackberry so I don't forget what its called.

ZiggyS1 (Programmer)

28 Jan 11 8:41

sorry feherke, I tried to * (Star) your post as well but it only let me do 2... is there a limit?

feherke (Programmer)

28 Jan 11 9:12

Quote (Ziggy):
sorry feherke, I tried to * (Star) your post as well but it only let me do 2... is there a limit?

As far as I know the star has to be unique per giver & receiver & thread. But I never read a concise rule regarding that.

Anyway, thank you for your kind intention.

Feherke.
http://free.rootshell.be/~feherke/

ZiggyS1 (Programmer)

28 Jan 11 9:25

np... got your star now :) I have 2 screens and the confirmation popped up out of view ó¿ó

ZiggyS1 (Programmer)

2 Feb 11 10:04

just another question, I can't put my finger on this.... sometimes when I first login the menu does not fully load, it will only display the field requiring input. This only seems to happen on the mobile scanner, and after a few scans the screen seems to refresh.

But the confusing thing is it only does it once, if I log out and login again it is fine, so it does not really seem to be the program.

feherke (Programmer)

3 Feb 11 3:10

Hi

Personally I feel inclined to blame the terminal and/or tput. Maybe the terminal failes to deliver correct environment information to tput or tput wastes so time with preparing its database for use.

Personally I would try it without tput, hoping that ANSI escape sequences will work on your terminal :

CODE

#!/bin/sh

LOGO='RF Scan Menu'
bold='\033[1m'
offbold='\033[0m'
counter=1
ORDN='
stmp="$( date )"
amenu='Type exit to close'

while :; do

  clear

  printf "
\t$bold Company $offbold
\t$bold %s $offbold

\txxxxxxxxxxxxxxxxxxxxxx
\tx %-18s x
\txxxxxxxxxxxxxxxxxxxxxx

\tScan Barcode

" "$LOGO" "$amenu"

  if [[ "$ORDN" == ' ]]; then
    echo -n '\tOrder: '
    read ORDN
    continue
  fi

  echo "\tOrder: $ORDN\n"

  echo -n "\tScan ( $(( counter++ )) ) : "
  read answer

  case "$answer" in
    'exit') break ;;
    *) echo "$ORDN,$answer,$stmp" >> '/home/zigsto/ScanTest2.txt' ;;
  esac

done

clear

Tested with mksh.

Feherke.
http://free.rootshell.be/~feherke/

ZiggyS1 (Programmer)

7 Feb 11 16:36

thanks feherke

I'll have to come back to that because it seems a bit different from what I am working with.

I probably should do new posts, but this is bugging me right now.....

I am using this expression to extract a portion of a string, but it gives me an error if I use letters in the variable

let lblval=$(echo `expr substr $lbl 3 $upc1`)

lblval=RRRR: 0403-009 The specified number is not valid for this
command.

p5wizard (IS/IT--Management)

7 Feb 11 16:48

let is for number variables only. just leave it out

CODE

lblval=$(command)

HTH,

p5wizard

feherke (Programmer)

8 Feb 11 6:11

Hi

As p5wizard already pointed out the error, I can only criticize your style ( again )

no need for expr
no need for that echo
no need for 2 child processes

CODE

lblval="${lbl:2:upc1}"

Feherke.
http://free.rootshell.be/~feherke/

ZiggyS1 (Programmer)

8 Feb 11 8:23

thanks p5wizard, that worked.

feherke, is your syntax giving me errors because I am using ksh and you are posting sh ? You last example gave me error, I tried exactly as you had it (curly braces).

error:

CODE

0403-011 The specified substitution is
not valid for this command.

PHV (MIS)

8 Feb 11 8:33

You should use a ksh93 version in order to use the ${parameter:offset:length} syntax.

Hope This Helps, PH.
FAQ219-2884: How Do I Get Great Answers To my Tek-Tips Questions?
FAQ181-2886: How can I maximize my chances of getting an answer?

feherke (Programmer)

8 Feb 11 8:50

Quote (Ziggy):
feherke, is your syntax giving me errors because I am using ksh and you are posting sh ?

It is KSH. ( See man ksh | Parameter Expansion. )

More exactly it is KSH93 syntax. Seems your is just KSH88.

CODE

master # lbl='ZiggyS1'

master # upc1=4

master # lblval="${lbl:2:upc1}"

master # echo "$lblval"
ggyS

master # echo "$KSH_VERSION"
@(#)MIRBSD KSH R33 2008/04/11

Then you will have to keep using expr, but the echo and one child process can still be removed :

CODE

lblval="$( expr substr "$lbl" 3 "$upc1" )"

( Note that you better quote your variables, because without them expr would fail if $lbl contains IFS characters or is empty. )

Feherke.
http://free.rootshell.be/~feherke/

ZiggyS1 (Programmer)

8 Feb 11 11:01

yes our version is 88, thanks for the tips. I am making good progress. I need to go back and clean up my code, there are many things to keep in mind but I have learned a ton since I started this project.

ZiggyS1 (Programmer)

9 Feb 11 10:50

feherke

had a chance to dissect this now....

This line...

CODE

echo "\tScan ( $(( counter++ )) ) : "

returns this error...

CODE

counter ++ : 0403-053 Expression is not complete; more tokens expe
cted.

I am not clear how it works, I gather it is a "Counter" and should display the quantity scanned.

the other thing I am not clear on is how do I position where to "read", with "tput cup" I had cursor positions to work with.

is \t a shortcut for print?

PHV (MIS)

9 Feb 11 11:31

Replace this:
$(( counter++ ))
with this:
$((counter+=1))

\t is a TAB char (tabulation)

Hope This Helps, PH.
FAQ219-2884: How Do I Get Great Answers To my Tek-Tips Questions?
FAQ181-2886: How can I maximize my chances of getting an answer?

ZiggyS1 (Programmer)

16 Feb 11 10:25

Thanks PHV,

I tried this script (posted by: feherke Feb 11 3:10 ), and it also has issue loading the menu complete on the first pass after logging into shell, I tried with ksh and sh, usually efter exiting the script and going back in the menu fully displays.

what is consistent is that the line being "Read" will always display, but things like the captions (except read line) or header do not.

*** this does not happen on a PC telnet, but only on

eg... first login....

CODE

Scan Barcode

Order:

After exiting Script....

CODE

Company
         RF Scan Menu

        xxxxxxxxxxxxxxxxxxxxxx
        x Type exit to close x
        xxxxxxxxxxxxxxxxxxxxxx

        Scan Barcode

        Order:

Telnet on Scanner (Symbol MC9090)

Wavelink CE Version 6.0.42

if you think this should go to another section in the forum, let me know.

thanks

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members!

Back To Forum

Back To UNIX Scripting

Member Login

Come Join Us!

LINK TO THIS FORUM!

Tek-Tips LinkedIn® Group

Partner With Us!

Feedback

Geography

Tek-Tips Shirts!

trouble with controlling loop in script and debugging(5)

CODE

CODE

CODE

CODE

CODE

CODE

CODE

Quote (SamBones):

Quote (Ziggy):

Quote (man ksh):

CODE

CODE

CODE

Quote (Ziggy):

CODE

CODE

CODE

CODE

Quote (Ziggy):

CODE

CODE

CODE

CODE

CODE

CODE

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Back To Forum

Join Tek-Tips® Today!

Tek-Tips LinkedIn^® Group

Join Tek-Tips^® Today!