Listing time every second as a Bash script
first time here as I've finally started to learn prog开发者_运维百科ramming. Anyway, I'm just trying to print the time in nanoseconds every second here, and I have this:
#!/usr/bin/env bash
while true;
do
date=(date +%N) ;
echo $date ;
sleep 1 ;
done
Now, that simply yields a string of date's, which isn't what I want. What is wrong? My learning has been rather messy, so I hope you'll excuse me for this if it's really simple. Also, I did manage to fine this, that worked on the prompt:
while true ; do date +%N ; sleep 1 ; done
But that obviously doesn't work as a script?
Edit, if anyone sees this: Ahh, this does indeed fix my error. I note you didn't add a ; Is that because I only defined a variable? Also, could you explain what the $ does? I thought it was for calling variables. And I see that the above line will indeed work as a script; I had expected the output of date to not be put on the screen.
Change
date=(date +%N) ;
to
date=$(date +%N)
This version should work
#!/bin/bash
while true; do
date=$(date +"%N")
echo Current date is $date
sleep 1
done
You can enclose your command between "`" (Backtick) too. For example:
date=`date +%N`
Regards
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