I have a file in which i have following content
2020-07-30 14:28:02|INFO|0||agent 1|CUpload|CUploadService
2020-07-30 14:28:02|INFO|0||agent 1|CUpload|CUpload
2020-07-30 14:28:04|INFO|0||agent 1|CUpload|CUplo
I need to write a script through which i can calculate the time difference. If time is more than 60 minutes since the file updated last time, i need to write the column 3 in another file.
I am able to get the date in right format but i dont know how to take difference so it will tell me if it has been more than 60 mins or not.
date +%Y-%m-%d" "%H:%M:%S
2020-07-30 14:47:24
I have placed two times in a file and took their difference but it came out to be zero
more 3.unl | awk -F '|' '{print$2 - $1}'
One possibility: convert date and time to epoch and subtract, eg:
#!/bin/bash
first='2020-07-30 14:28:04'
later='2020-07-30 15:39:09'
ep1=$(date --date="$first" +%s)
ep2=$(date --date="$later" +%s)
diff=$((ep2 - ep1))
echo diff $diff
if (( $diff > 3600 )); then
echo actions ...
fi
I would like to find number of days from two given dates as 25 Aug 2017 and 05 Sep 2017.
My script:
start='2017-08-25';
end='2017-09-05';
ndays=(strtotime($end)- strtotime($start))/24/3600;
echo $ndays
When run this script, I am getting following error messages.
Line 3: syntax error near unexpected token `('
Desire output value:
10
No shell that I am aware of has any tools for working with dates. At the very least, you need an external tool like date to convert your dates to an intermediate form, like the number of seconds since some fixed point in time (Unix uses Jan 1, 1970), then do your calculation with those values before processing the result further.
Assuming the use of GNU date from the Linux tag, you would do something like
start='2017-08-25'
end='2017-09-05'
start_seconds=$(date +%s --date "$start" --utc)
end_seconds=$(date +%s --date "$end" --utc)
ndays=$(( (end_seconds - start_seconds) / 24 / 3600 ));
echo $ndays
Note that since most shells only support integer arithmetic, this won't give you an exact number of days.
You can use date to convert each date to epoch seconds, then use arithmetic expansion to do the subtraction and conversion back to days:
#! /bin/bash
start='2017-08-25';
end='2017-09-05';
diff=$(date -d $end +%s)-$(date -d $start +%s)
echo $(( ($diff) / 60 / 60 / 24 )) # 11
I have this script I am building and need a bit of help. I want to use as minimal lines of code as possible. However what I want the script to do is the following.
Backup a specified file such as authlog into a new file with the keywords I specify.
However. I also want it to back up the file if current backed up file is older than 2+ days ago and if it is newer. Leave it alone. if (file) is older than +2 days old delete it and replace it with an updated one.
I'm getting integer expression expected and I'm not sure how to fix it
#!/bin/bash
authlog=/home/(myhomedir)/logs/backups/authlog-${current_date}
backup="$(cat /var/log/auth.log | grep -e failed -e invalid > /home/(myhomedir)/logs/backup)"
dayold=$(date -d '1 day ago' "+%Y-%m-%d")
current_date=$(date +"%m_%d_%Y")
if [ $authlog -lt $dayold ] ;
then ${backup}
else
echo $authlog is newer than $current_date $authlog has not been updated
if [ $authlog -eq ${current_date} ]
then "$(rm {authlog})"
fi
fi
You can't use -lt to compare non-numeric strings. This is why you're getting "integer expression expected". You're trying to compare a filename to a date string.
The easiest way to compare dates is by converting them to seconds since epoch (Jan 1, 1970 00:00:00 UTC). As an example, suppose I have a file called foo.bar and I want to check if it was last modified 3 or more days ago:
filetime=$(stat -c %Y foo.bar)
three_days_ago=$(date -d "3 days ago" +%s)
if [ $filetime -lt $three_days_ago ]; then
echo "foo.bar was last modified more than 3 days ago"
fi
Also, your authlog variable does not contain a date. I'm assuming there's a missing step that you forgot.
In my linux system date is having two space between month and date(ex:Jun 4) .so i used date command(ex:date +'%b %_d %H') and stored the value in variable that time i am getting only one space between month and date(ex:Jun 4), so please help me to get the actual system format while using variable.
date is outputting the string you want; I suspect you aren't properly quoting the variable value when you expand it.
$ d=$(date +'%b %_d %H')
$ echo $d
Jun 6 20
$ echo "$d"
Jun 6 20
I have a shell script that runs on Linux and uses this call to get yesterday's date in YYYY-MM-DD format:
date -d "1 day ago" '+%Y-%m-%d'
It works most of the time, but when the script ran yesterday morning at 2013-03-11 0:35 CDT it returned "2013-03-09" instead of "2013-03-10".
Presumably daylight saving time (which started yesterday) is to blame. I'm guessing the way "1 day ago" is implemented it subtracted 24 hours, and 24 hours before 2013-03-11 0:35 CDT was 2013-03-09 23:35 CST, which led to the result of "2013-03-09".
So what's a good DST-safe way to get yesterday's date in bash on Linux?
I think this should work, irrespective of how often and when you run it ...
date -d "yesterday 13:00" '+%Y-%m-%d'
Under Mac OSX date works slightly different:
For yesterday
date -v-1d +%F
For Last week
date -v-1w +%F
This should also work, but perhaps it is too much:
date -d #$(( $(date +"%s") - 86400)) +"%Y-%m-%d"
If you are certain that the script runs in the first hours of the day, you can simply do
date -d "12 hours ago" '+%Y-%m-%d'
BTW, if the script runs daily at 00:35 (via crontab?) you should ask yourself what will happen if a DST change falls in that hour; the script could not run, or run twice in some cases. Modern implementations of cron are quite clever in this regard, though.
Here a solution that will work with Solaris and AIX as well.
Manipulating the Timezone is possible for changing the clock some hours.
Due to the daylight saving time, 24 hours ago can be today or the day before yesterday.
You are sure that yesterday is 20 or 30 hours ago. Which one? Well, the most recent one that is not today.
echo -e "$(TZ=GMT+30 date +%Y-%m-%d)\n$(TZ=GMT+20 date +%Y-%m-%d)" | grep -v $(date +%Y-%m-%d) | tail -1
The -e parameter used in the echo command is needed with bash, but will not work with ksh.
In ksh you can use the same command without the -e flag.
When your script will be used in different environments, you can start the script with #!/bin/ksh or #!/bin/bash. You could also replace the \n by a newline:
echo "$(TZ=GMT+30 date +%Y-%m-%d)
$(TZ=GMT+20 date +%Y-%m-%d)" | grep -v $(date +%Y-%m-%d) | tail -1
date -d "yesterday" '+%Y-%m-%d'
To use this later:
date=$(date -d "yesterday" '+%Y-%m-%d')
you can use
date -d "30 days ago" +"%d/%m/%Y"
to get the date from 30 days ago, similarly you can replace 30 with x amount of days
Just use date and trusty seconds:
As you rightly point out, a lot of the details about the underlying computation are hidden if you rely on English time arithmetic. E.g. -d yesterday, and -d 1 day ago will have different behaviour.
Instead, you can reliably depend on the (precisely documented) seconds since the unix epoch UTC, and bash arithmetic to obtain the moment you want:
date -d #$(( $(date +"%s") - 24*3600)) +"%Y-%m-%d"
This was pointed out in another answer. This form is more portable across platforms with different date command line flags, is language-independent (e.g. "yesterday" vs "hier" in French locale), and frankly (in the long-term) will be easier to remember, because well, you know it already. You might otherwise keep asking yourself: "Was it -d 2 hours ago or -d 2 hour ago again?" or "Is it -d yesterday or -d 1 day ago that I want?"). The only tricky bit here is the #.
Armed with bash and nothing else:
Bash solely on bash, you can also get yesterday's time, via the printf builtin:
%(datefmt)T
causes printf to output the date-time string resulting from using
datefmt as a format string for strftime(3). The corresponding argu‐
ment is an integer representing the number of seconds since the
epoch. Two special argument values may be used: -1 represents the
current time, and -2 represents the time the shell was invoked.
If no argument is specified, conversion behaves as if -1 had
been given.
This is an exception to the usual printf behavior.
So,
# inner printf gets you the current unix time in seconds
# outer printf spits it out according to the format
printf "%(%Y-%m-%d)T\n" $(( $(printf "%(%s)T" -1) - 24*3600 ))
or, equivalently with a temp variable (outer subshell optional, but keeps environment vars clean).
(
now=$(printf "%(%s)T" -1);
printf "%(%Y-%m-%d)T\n" $((now - 24*3600));
)
Note: despite the manpage stating that no argument to the %()T formatter will assume a default -1, i seem to get a 0 instead (thank you, bash manual version 4.3.48)
You can use:
date -d "yesterday 13:55" '+%Y-%m-%d'
Or whatever time you want to retrieve will retrieved by bash.
For month:
date -d "30 days ago" '+%Y-%m-%d'
As this question is tagged bash "DST safe":
And using fork to date command implie delay, there is a simple and more efficient way using pure bash built-in:
printf -v tznow '%(%z %s)T' -1
TZ=${tznow% *} printf -v yesterday '%(%Y-%m-%d)T' $(( ${tznow#* } - 86400 ))
echo $yesterday
This is a lot quicker on more system friendly than having to fork to date.
From bash version 5.0, there is a new variable $EPOCHSECONDS
printf -v tz '%(%z)T' -1
TZ=$tz printf -v yesterday '%(%Y-%m-%d)T' $(( EPOCHSECONDS - 86400 ))
echo $yesterday