Here is the problem:

I have a file with some strings separated by spaces, and with delimiters, e.g.


1 2 3 4 5 ~1 2 3 4 5 ~
1 2 3 4 5 ~1 2 3 4 5 ~
1 2 3 4 5 ~1 2 3 4 5 ~


I want to replace the spaces between the field and the delimiters to some character (@ in this example)


1 2 3 4 5@@@@~1 2 3 4 5@@@~
1 2 3 4 5@@@@~1 2 3 4 5@@@~
1 2 3 4 5@@@@~1 2 3 4 5@@@~

The regexes I have tried so far are obviously wrong:

sed 's/[ ]*~/@/g' # will replace all spaces with a single @
sed 's/[ ]/@/g' # will replace all spaces, even those within data with a # single @

Any ideas?

Please explain further what a field is?

Hi,

please use code-tags in the future so that we can see how many spaces there are in the sample data.

As for your problem, try this:
Requires GNU sed.