Shell Programming and Scripting

vgersh99


The o/p wants to detect the absence of field2 and field3.

vino

empty fields are also spaces. but i need them to be shown as a blank in the output.

yes, exactly. the absence of field2 and 3 are not detected. thanks vino for explaining it

If field2 and field3 always follow a same pattern, then look for its absence, and introduce a ;

Vino

there are no patterns, because all the fields are numbers. they can either be blank or numbers.

however, the number of fields in each line is the same. i am not sure if this will be a helpful pt to make use of

Add this as well to the original solution.

Code:

sed -e 's/^\([0-9][0-9]*\);\([0-9][0-9]*\)$/\1;;;;\2/g'

A very crude one tho'.

Vino

A hint: Looks like each field starts and ends in well defined columns with a variable number of trailing spaces to fill the field. You're going to need to exploit that property for a correct solution. We need the starting column numbers. With a modern sed, it is an easy two step process. Deposit a separator after, say, columns 10, 15, 20, 40. Then remove spaces before the separator.