How to add spaces in certain columns of a file in Linux

Question

I have a text file containing 1000 lines in this format:

001122 abc def ghi 334455 xyz aaa bbb 667788 ccc ccc ddd 

How can I convert it into this format using a Linux command by adding spaces to certain columns?

00 11 22 abc def ghi 33 44 55 xyz aaa bbb 66 77 88 ccc ccc ddd 

Answer 1

Naively but straight forward:

$ sed 's/\(..\)\(..\)\(..\)/\1 \2 \3/' file 00 11 22 abc def ghi 33 44 55 xyz aaa bbb 66 77 88 ccc ccc ddd 

That is, match and collect the three first groups of two characters on each line, and space them out by inserting spaces in the replacement string.

Fancy but requires thinking:

$ sed 's/../ &/3; s/../ &/2' file 00 11 22 abc def ghi 33 44 55 xyz aaa bbb 66 77 88 ccc ccc ddd 

This first expression replaces the 3rd match of .. on each line with a space followed by whatever those .. matched. Then again, but for the 2nd match.

Answer 2

Using any awk in any shell on every UNIX box and letting you specify which column to change and independent of the characters in that column:

$ awk -v c=1 '{gsub(/../,"& ",$c); sub(/ $/,"",$c)}1' file 00 11 22 abc def ghi 33 44 55 xyz aaa bbb 66 77 88 ccc ccc ddd $ awk -v c=2 '{gsub(/../,"& ",$c); sub(/ $/,"",$c)}1' file 001122 ab c def ghi 334455 xy z aaa bbb 667788 cc c ccc ddd $ awk -v c=3 '{gsub(/../,"& ",$c); sub(/ $/,"",$c)}1' file 001122 abc de f ghi 334455 xyz aa a bbb 667788 ccc cc c ddd 

Answer 3

A simple sed command is all that is needed (change filename with the acutal file):

sed -E 's|([0-9]{2})([0-9]{2})([0-9]{2})[[:blank:]]*(.*)|\1 \2 \3 \4|g' filename 

If you want to change the source file (filename) in place, pass in the -i option:

sed -i -E 's|([0-9]{2})([0-9]{2})([0-9]{2})[[:blank:]]*(.*)|\1 \2 \3 \4|g' filename 

Explanation:

([0-9]{2}) matches groups of 2 digits 3 times

(.*) matches everything else which is all the letters

[[:blank:]]* matches space characters including tabs

\1 through \4 are matched groups

Note that this will only work with GNU sed. Almost all mainstream Linux distributions come with GNU Linux. If you are using macOS, your sed is BSD sed, unless your installed GNU sed available as gsed.

Answer 4

A Generic version for any number/position of spaces in awk:

awk -v s='2,4' '{f=!split(s,a,",");for(i in a){r="^.{"a[i]+f++"}";gsub(r,"& ")}}1' 00 11 22 abc def ghi ⋮ 

A more powerful version, where other characters than space can be inserted:

spacers(){ awk -v s="$1" '{f=!split(s,a,/[^*0-9]*/);split(s,p,/[*0-9]*/); for(i in a){if(""==b=a[i])continue; r="^.{"(b!="*"?b+f++:length($0))"}"; gsub(r,"&"p[i+1])}} 1' $2;} 

That way, you can do e.g.:

spacers '0|2 4 6|[email protected] |* |' file |00 11 22| [email protected] | def ghi | 

which is great for creating org-mode tables and piping directly to clipboard.

Note: The shell-function also accepts data through STDIN.

(Earlier versions of this answer contained a generic awk-solution, that used sed for the final replace)

Answer 5

Being completely lazy about typing here,

sed -E "s/([0-9]{2})/\1 /g; s/ +/ /g" file1 

Put a space after every pair of digits and then reduce the multiple spaces to a singleton.

Or, perhaps even lazier

sed 's/./& /4;s/./& /2' file1 

Answer 6

If the input data is exactly as depicted, GNU cut is an option. Note that the --output-delimiter has to be explicitly set to a space. This makes for a very rigid solution unlike some of the other answers, lacking both the flexibility to deal with variable string length in the first field and the ability to designate an arbitrary field to operate on.

cut -c1-2,3-4,5- --output-delimiter=' ' <file 00 11 22 abc def ghi 33 44 55 xyz aaa bbb 66 77 88 ccc ccc ddd