Shell Programming and Scripting

Hi Everyone,

I am working on Sun solaris. I would like to know that ,do we any way to
create unique batch in shell scripts.Basically i want to create a batch and want to create a sequence to process the records.

Regards,
gehlnar

Are you talking about a unique sequence number, like databases provide?
Obviously if you have a database like Oracle you can get one by querying a sequence.
Otherwise, you will have to write a starting number to a file.
Every time you want the next sequcne, read the file, add one to the number, write the new number back to the file, then save the new number as your sequence.
Create starting number - like say 1000000

Code:

echo  "1000000"  > sequence.dat

using the sequence later - as a function that you call

Code:

sequence()
{
   if [[ -w sequence.dat ]] ; then
    a=$(<sequence.dat)
    a=$(( $a + 1 ))
    echo $a > sequence.dat
    echo $a
   else 
     echo "Error sequence not setup" > 2
     exit 1
   fi

}

#usage
newsequence=$( sequence)
# use $newsequence for something
.....................

Hi Jim,

Thanks for the idea given by you. I was looking for something like this. actually we do not have any particular database on from which i can generate sequence.

Let me see how i can make use of it.

Cheers,
gehlnar

A read command will be much faster than command substitution in all shells except ksh93:

Code:

read a < sequence.dat