Format output and columms

Question

In Linux in Bash in a for loop i do:

... ; do echo "$i --> $i-new" ; ...

The output is than something like this:

file1  -->  file1-new
file2  -->  file2-new
...
file9  -->  file9-new
file10  -->  file10-new
file11  -->  file11-new

how to become an output like this:

file1   -->   file1-new
file2   -->   file2-new
...
file9   -->   file9-new
file10  -->  file10-new
file11  -->  file11-new

?

Answer 1

for i in file{1..11}; do
    printf '%s\t-->\t%s\n' "${i}" "${i}-new"
done | column -t -d -s$'\t' -R3

• printf '%s\t-->\t%s\n' "${i}" "${i}-new": prints three tab-separated columns for, respectively, fileN, --> and fileN-new

In column:

• -t: create a table, with columns separated by two spaces
• -d: don't print the table's header
• -s$'\t': assume the input items are tab-separated
• -R3: align the contents of column #3 to the right

% for i in file{1..11}; do printf '%s\t-->\t%s\n' "${i}" "${i}-new"; done | column -t -d -s$'\t' -R3
file1   -->   file1-new
file2   -->   file2-new
file3   -->   file3-new
file4   -->   file4-new
file5   -->   file5-new
file6   -->   file6-new
file7   -->   file7-new
file8   -->   file8-new
file9   -->   file9-new
file10  -->  file10-new
file11  -->  file11-new