Manage starting point in shell script.

ai_dba · #1 (**permalink**) 08-28-2007

Hi,
I'd like to run a script with an optional starting point.
Meaning that if no parameter for the script => Do everything, otherwise start from the point specified in the parameter and continue till the end.

I thought of using the "case ..." but I have no result.
Script:
# ---------------
START_POINT=$1
if [ "$START_POINT" = "" ]
then
START_POINT="a"
fi
echo ">$START_POINT<"
case $START_POINT in
"a") echo "Running >a<!";;
"b") echo "Running >b<!";;
"c") echo "Running >c<!";;
"d") echo "Running >d<!";;
default) echo "Wrong value for starting point";;
esac
return
# ---------------
result expected:
> script [nothing]
Running >a<!
Running >b<!
Running >c<!
Running >d<!

> script c
Running >c<!
Running >d<!

> script k
Wrong value for starting point

Please provide some help.
Thanks in advance.
Regards!

Yogesh Sawant · #2 (**permalink**) 08-28-2007

Alternatively, you can write functions to do specific tasks and then call them as per needed. If no arguements are passed to the script, call all the functions.

ai_dba · #3 (**permalink**) 08-29-2007

Yes, that'a an alternative.
My main issue is to manage the starting point in the script, not running every thing.

Thanks.

Yogesh Sawant · #4 (**permalink**) 08-29-2007

if you are using tcsh, then you can take help of goto to do what you want. bash and ksh does not support goto.

Also, have a look at this (that person might have solved his problem without using goto)

robotronic · #5 (**permalink**) 08-29-2007

It's much more simpler if you use numbers as starting points:

Code:

START_POINT="$1"

if [ ! "$START_POINT" ]; then START_POINT=0; fi

if [ "$START_POINT" -le 10 ]; then echo "Running 10!"; fi
if [ "$START_POINT" -le 20 ]; then echo "Running 20!"; fi
if [ "$START_POINT" -le 30 ]; then echo "Running 30!"; fi

Then you specifiy a parameter and, if the number is lesser than the execution step, the code will be executed.

vino · #6 (**permalink**) 08-29-2007

Put the case-esac construct in a while loop.

Code:

[/tmp]$ cat test.ksh
#! /bin/ksh
#

while :
do
    case $1 in
        "") set -- a ;;
        "a") echo "a" ; set -- b ;;
        "b") echo "b" ; set -- c ;;
        "c") echo "c" ; set -- d ;;
        "d") echo "d" ; break ;;
        *) echo "Wrong" ; break ;;
    esac
done
[/tmp]$ ./test.ksh
a
b
c
d
[/tmp]$ ./test.ksh a
a
b
c
d
[/tmp]$ ./test.ksh c
c
d
[/tmp]$ ./test.ksh d
d
[/tmp]$ ./test.ksh z
Wrong
[/tmp]$ ./test.ksh abcd
Wrong
[/tmp]$

ai_dba · #7 (**permalink**) 08-29-2007

Perfect!

That's it.

Thanks a lot vino

.

Thanks also to others, I will use some answers for something else

.

Regards.

Antonio.

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
facing problem in starting a process in background using shell script.	dtomar	Shell Programming and Scripting	8	04-17-2008 08:11 AM
shell script for extracting out the shortest substring from the given starting and en	pankajd	Shell Programming and Scripting	18	03-10-2008 06:20 AM
Trying to manage an inherited Ksh script	ajcannon	Shell Programming and Scripting	1	08-15-2007 06:54 AM
Help starting a simple shell script.	dickmartin	Shell Programming and Scripting	2	07-29-2004 09:02 AM
How to manage multiple versions of a set of shell and SQL script utilities	DennisB	Shell Programming and Scripting	2	06-23-2004 08:13 AM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread: