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How can I read a line from a file into two variables: one variable for the last field, and the the other variable for the other fields?

For example, I have a file:

hello world! 10s
It is a good day. 4m
...

I would like to read each line into two variables: one variable contains the time interval at the end of the line, and the other variable contains the fields before it. I was wondering how to do it; this is as far as I have gotten:

while read line 
do
    ...  # split $line into $message and $interval
    myprogram "$message" "$interval"
done < "$inputfile" 
7
  • Will the interval ever contain white space?
    – jesse_b
    Commented Nov 8, 2018 at 23:02
  • Thanks. The time interval will be used as argument to sleep. If sleep accepts an argument with a space within it, then yes; otherwise, no.
    – Tim
    Commented Nov 8, 2018 at 23:04
  • Obligatory unix.stackexchange.com/q/169716/117549
    – Jeff Schaller
    Commented Nov 8, 2018 at 23:44
  • @JeffSchaller Could you tell me how I should rewrite my while loop? I have looked at the link
    – Tim
    Commented Nov 8, 2018 at 23:48
  • It's apparent that reading into variables is not your final destination; there might be other/better ways to accomplish your goal, if we knew what it was.
    – Jeff Schaller
    Commented Nov 8, 2018 at 23:51

1 Answer 1

3

As long as the interval contains no whitespace this should work:

#!/bin/bash

input=/path/to/input

while read -r line; do
    message=${line% *}
    interval=${line##* }
    echo "$message"
    sleep "$interval"
done < "$input"

${line% *} Will strip everything after the last space character

${line##* } Will strip everything before the last space character

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