Score:-1

Ubuntu

How to compare time in if condition?

Haridvpsk

1/23/23, 5:13 AM

#!/bin/bash
tag=$(awk -F, 'NR==1{print $1}' /tmp/time.txt)# output: 17:00
sub_time=$(date -d"${tag}  +1:00" +'%H:%M')output: 16:00
current_time=$(date |awk 'NR==1{print $4}' output: 05:51:16
if [[ "$sub_time" -ge "$current_time" ]];then
   crontab  <<EOF
   */15 * * * *  bash server_shutdown.sh
EOF
fi

I want to compare the "current_time" in the current system to the VM shutdown tag from VM with "sub_time" through the if condition.

223

0 + 0

bash

pLumo

1/23/23, 6:16 AM

What are you trying to do? What is subtime? Why 17:00+1 = 16:00? Why do you use `awk` to filter output of `date` instead of using `date`s format string? What does not work (any errors)? Obviously `-ge` can only compare integers ... but you should still add this to the question.

Score:1

Ubuntu

pLumo

1/23/23, 6:21 AM

It would be safer to convert the date strings to timestamps:

%s seconds since 1970-01-01 00:00:00 UTC

[[ $(date +%s -d "$sub_time") -ge $(date +%s -d "$current_time") ]]

Of course you could directly do this when creating the variables:

sub_time=$(date -d"${tag}  +1:00" +%s)
current_time=$(date +%s)
if [[ $subtime -ge $current_time ]]; then
   ...
fi

Instead of creating current_time by yourself, you could use the bash variable $EPOCHSECONDS (bash > 5.0).
You could also use printf instead of date to create it: printf -v current_time '%(%s)T'

Be aware that these options might not be very portable.

0 + 0

Haridvpsk

1/23/23, 9:18 AM

azureuser@puppetclient-ubuntu:~$ echo $current_time "1632388663" azureuser@puppetclient-ubuntu:~$ echo $sub_time 1632384000 else condition is getting executed why.?

Score:0

Ubuntu

Mahek Shamsukha

1/23/23, 6:26 AM

#!/bin/bash
tag=$(awk -F, 'NR==1{print $1}' /tmp/time.txt)# output: 17:00
sub_time=$(date -d"${tag}  +1:00" +'%H:%M')#output: 16:00
current_time=$(date |awk 'NR==1{print substr($5,0,5)}')#output: 05:51
# on my system the 5th field has the time while the 4th field has the year.
# so I changed that in awk
if [[ "$sub_time" > "$current_time" ]];then # comparison done lexicographically
   crontab  <<EOF
   */15 * * * *  bash server_shutdown.sh
EOF
fi

0 + 0

pLumo

1/23/23, 6:46 AM

Instead of filtering `date` output with `awk`, why not simply use `date +%H:%M` ?

Haridvpsk

1/23/23, 9:26 AM

after if condition get satisfied also my cron job is not created why?

Haridvpsk

1/23/23, 2:53 PM

Thanks a lot Mr.PLumo & Mahek the both the answers works for me .