Issue with column command and color escape codes

Question

I'm colorizing the header of a table formatted with column -ts $'\t'

Works well without color codes, but when I add color codes to the first line column doesn't properly align the output.

Without colored output it works as expected:
printf "1\t2\t3\nasdasdasdasdasdasdasd\tqwe\tqweqwe\n" | column -ts $'\t'

But when adding color on the first line column doesn't align the text of the colored row:
printf "\e[7m1\t2\t3\e[0m\nasdasdasdasdasdasdasd\tqwe\tqweqwe\n" | column -ts $'\t'

Observed this behaviour both on Ubuntu Linux and Mac OS X.

Answer 1

Yes, that's because the color codes are also being formatted by column. They are characters just like any other. Since you're already using printf though, you may as well use it to do the formatting for you:

$ printf '\e[7m%-24s%-8s%-6s\e[0m\n%-24s%-8s%-6s\n' "1" "2" "3" "asdasdasdasdasdasdasd" "qwe" "qweqwe"
1                       2       3     
asdasdasdasdasdasdasd   qwe     qweqwe

Alternatively, you can add the color codes after using column:

$ printf "1\t2\t3\nasdasdasdasdasdasdasd\tqwe\tqweqwe\n" | column -ts $'\t' | 
    sed "1{s/^/$(printf '\e[7m')/;s/$/$(printf '\e[0m')/}"
1                      2    3   # this line is colored
asdasdasdasdasdasdasd  qwe  qweqwe

Answer 2

I imagine that column doesn't know that \e[7m is a v100 escape sequence that takes no space in the output. It seems to asssume character codes 0 to 037 octal take no space. You can get what you want by putting the initial escape sequence on a line of its own, then removing that newline from the output:

printf '\e[7m\n1\t2\t3\e[0m\nasdasdasdasdasdasdasd\tqwe\tqweqwe\n' | 
column -ts $'\t' |
sed '1{N;s/\n//}'