CODEWITHSUNDEEP
linuxbashfileloops
Leam
Leam

Reputation: 53

Using lines from a file while looping over an unrelated numeric range in bash

I got a task to display all bash fonts/colors/background colors in table where the text is different for each variation and is being taken from file that contains 448 words/random number(I'm working with numbers). Here is my code for displaying all variations 

for i in {0..8}; do 
for j in {30..37}; do 
for n in {40..47}; do 
echo -ne "\e[$i;$j;$n""mcolors"
done
echo
done
done
echo ""

Output: enter image description here

Code for generating random numbers: 

#!/bin/bash 
for ((i=0;i<$1;i++))
do
echo $RANDOM >> randomnumbers.sh
done

So the question is how can I pass numbers from randomnumbers.sh to my script so "colors" line in output changes to number being taken by order from randomnumbers.sh? Thanks!

Upvotes: 0

Views: 57

Answers (1)

Charles Duffy
Charles Duffy

Reputation: 295510

One simple approach is to have an open file descriptor with your random numbers, and read a line from that file whenever such a value is required.

Here, we're using FD 3, so that other parts of your script can still read from original stdin:

#!/usr/bin/env bash

# Make file descriptor 3 point to our file of random numbers (don't use .sh for data files)
exec 3< randomnumbers || exit

for i in {0..8}; do 
  for j in {30..37}; do 
    for n in {40..47}; do
      read -r randomNumber <&3                                 # read one number from FD 3
      printf '\e[%s;%s;%sm%05d' "$i" "$j" "$n" "$randomNumber" # & use in the format string
    done
    printf '\n'
  done
done
printf '\n'

Upvotes: 2

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