Shell Programming and Scripting

But it then removes the spaces that I already have, e.g.

Code:

awk -v OFS='       ' '{$1=$1};1' f1 | awk '{ print $1","$2":"$3 }'

removes the space I created before the pipeline !

I do not want to change the spaces between columns if I already have. Recreating the spaces artificially by another pipeline may not be desired.

Code:

sed '
s/ \( *\)/:\1/2
s/ \( *\)/,\1/1
' f1

Correct, Those are two different examples, the first one just shows how to use the Output Field Separator(OFS) to specify exactly what goes between each field, the second one just shows how to output the fields specifying a character or characters to place between each field without using Output Field Separator(OFS), so when you piped the first one into the second one the spaces you created between each column in the first one are dropped and it outputs the ',' and ':' between the columns.
Using the second awk example(awk '{ print $1","$2":"$3 }' f1) you can specify something different between each column( space(s), comma, colon, slashe(s), etc.

I think I can create my own spaces and insert comma, colon etc between them. But it may be difficult to exploit the spacing that I already have between columns.

Why did my previous post not meet your requirement?
The \( *\) matched the extra space characters and \1 inserted them back.
\( *\) matches all the space characters i.e. the entire space.
The /2 addresses the 2. space while the /1 addresses the 1. space.
Two more examples:

Code:

sed '
s/\(  *\)/:\1/2
s/\(  *\)/,\1/1
' f1

Code:

sed '
s/\(  *\)/  \1/2
s/\(  *\)/  \1/1
' f1

The colon and comma sit just after column 2 and column 1. Can I place them in the middle of the spaces?

For example, if I have 4 spaces, a comma will sit on the 3rd space and there will be a gap of 5 spaces between the columns (including the comma in the middle).

For odd number of spaces, we can make a choice, such as make even by adding an extra space and then put the comma in the middle.

We can exploit this idea to generate a table while I'll be inserting '|' in the middle of two columns.

I was expecting some 'awk' commands, but don't know whether that could be possible.

Thanks anyway.

You can match and re-add a space character at the beginning:

Code:

sed '
s/ \( *\)/ :\1/2
s/ \( *\)/ ,\1/1
' f1

Attempts to find the middle with \( *\)\1 are problematic;
the following only works with all spaces being even number of space characters:

Code:

sed '
s/\(  *\)\1/\1:\1/2
s/\(  *\)\1/\1,\1/1
' f1

---------- Post updated at 01:59 PM ---------- Previous update was at 01:52 PM ----------

Hmm, I am surprised, it seems to work even with odd spaces.