Cfrtjryk

I have been attempting to create a file out of my loop in bash , I was successful in generating the file with the following code

for ((i = 0; i <= 5; i++)); do

  for ((j = i; j <= 5; j++)); do

    echo -e "$i $j" >> numbers.txt

  done 

done

however I want my results to be out in the following fashion

 01



 02



 03

etc.

But the result I am getting is similar to this

0 0 1 0 2 0 3 0 4 0 5 1 1 1 2 1 3 1 4 1 5 2 2 2 3 2 4 2 5 3 3 3 4 3 5

How can I solve this ?

bash has C-style for loops, but stylistically they're a little odd to use when you don't have to. And if you really do absolutely have to, you might be using the wrong language. (For this use case shell is fine, of course.)

A much more shell-like way to do this (in my opinion) is:

for i in {0..5}; do for j in $(seq "$i" 5); do echo "$i$j"; done; done

Here is another approach:

(set {0..5}; for i; do for j; do [ "$i" -le "$j" ] && echo "$i$j"; done; done)

I write these as one-liners suitable for an interactive shell, but they work equally well in structured form (which would usually be preferable in a script):

set {0..5}

for i; do

  for j; do

    [ "$i" -le "$j" ] &&

      printf '%d%dn' "$i" "$j"

  done

done

for ((i = 0; i <= 5; i++)); do

  for ((j = i; j <= 5; j++)); do

    echo -e "${i}${j}n" >> numbers.txt

  done 

done

Should do the trick. I removed the space, I prefer using {}'s around my variables and n puts in new line.