parse and concatenate fields

[alfie002]

Hello all,

I have a file with the following format of fields on each line of the file.The number of fields is variable and can vary from 2 fields to 6

EG:

field1 field2 field3

I need to be able to read the file, read each line and then concatenate the fields on each line with a "_".

EG

field1_field2_field3

The entries should then be written to a new file.

Help would be appreciated.

Thanks

Alf

 

[PHV]

Why not simply this ?
sed 's! !_!g' /path/to/input > output

Hope This Helps, PH.
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