Shell Programming and Scripting

if you take a a closer look at the previous suggestions, you'll see that there's no assumptions of the 'number of underscores/dashes in the file. The only assumption (based on your sample file] is that you want to get the 'next to last' field in the underscoreORdash separated record/line.

Is the above correct description of the objective?

Code:

sed 's/.*[-_]\([^-_][^-_]*\)[-_].*/\1/' myFile

from left to right:

.* - any character repeated 0 or more times - greedy - will consume ALL the character leading to the LAST non-underscore/non-dash char followed b dashORunderscore.
[-_] - followed by either a '-' or a '_' char
\([^-_][^-_]*\) - followed by a 'capture' of any character other then '-' or '_' repeater 0 or more times.
[-_] - followed by either a '-' or a '_' char
.* - any character repeated 0 or more times - greedy
\1 - replace the 'matched' string with the FIRST 'capture'

I know it might be a bit confusing reading the regEx expressions at times, but try to think 'pattern matching'....

yes your objective is absolutely correct but how do I use this command

sed 's/.*[-_]\([^-_][^-_]*\)[-_].*/\1/' myFile in my below script.


Myscript

for DATA in `cat $IN_FILE/a.txt`
do
BSC_ID=`echo $DATA | awk -F[_-] '{print $(NF-1)}`
echo $BSC_ID
done

and the output is

BSC403_JAIN03|3153_TropicalFarm_LIMJM1-3_97|
BSC403_JAIN03|3410_PantaiAcehPCEHM1_4_97|
BSC406_BMIN02|1433_JomHebohTV3_COW7M1_11_97|

which is incorrect.

Thanks a lot for the explaination....
This is really good work.

.... the same way you've used the 'awk' suggestion - although you've missed a single-quote from the original suggestion.

Here's the modified 'awk' way with optimized non-UUOC code - what the purpose of the 'for' loop?:

Code:

awk -F[_-] '{print $(NF-1)}' $IN_FILE/a.txt

The same results can be achieved with the similar 'sed' solution no need for the 'for' loop either:

Code:

sed 's/.*[-_]\([^-_][^-_]*\)[-_].*/\1/' $IN_FILE/a.txt

cat filename | sed 's/-/_/' | awk -F"_" '{print $5}'

cat and sed and awk...... why?