Question

I need to sort a file based on the number of chars in the first column.

I have no idea on how to go about this. I’m using Linux, so sed/awk/sort are all available.

.abs is bla bla 12 
.abc is bla se 23 bla
.fe is bla bla bla
.jpg is pic extension
.se is for swedish domains

What I want is to sort these lines, based on the length of the first column in each line.
Some of the lines start with 4 characters, some start with 3, or 2. I want the result to be something like:

.fe is bla bla bla 
.se is for swedish domains 
.abs is bla bla 12 
.abc is bla se 23 bla 
.jpg is pic extension 

Is this even possible?

Answer 1

Augment each line by the length of the first word, then sort:

awk '{ print length($1) " " $0; }' $FILE | sort -n

If necessary, cut out the helper field with cut -d ' ' -f 2- afterwards.