I have a function that receives date as an argument and I need to format it so it would work on older FreeBSD on our school server.
selected_date=$(date -j $1 +"%Y-%m-%d")
This is what I have so far. Could someone advise me how to correct it so it would work?
The Code has not change in the last FreeBSD releases.
Make sure your input argument is quoted.
use option -f to specify the date format of your input
if you have non numeric input data, ensure the locale is set.
Example, tested on FreeBSD 8.4 and FreeBSD 11.1:
env LANG=C date -j -f '%b %d %T %Z %Y' 'Dec 24 02:12:21 CET 2016' '+%Y-%m-%d'
Related
I'm trying to calculate the number of seconds since the Epoch, using date on MacOS BSD.
I can get a one year ago date string:
$ date -v -1y
Tue Apr 21 10:44:47 EST 2020
...but I can't figure out how to convert it into seconds since Epoch. Any suggestions?
Add +%s to tell it to print the datetime as seconds since the epoch:
date -v -1y +%s
The + is a date option to set the output format, and %s is strftime format for "seconds since epoch".
Portability note: while the +%s part is pretty standard and portable (though the %s format is not actually required by POSIX), the -v -1y part is wildly nonportable. With GNU date (e.g. on most Linuxes), you'd use something like --date='1 year ago' instead. On NetBSD, -d '1 year ago' works. Check your local man page to see what your system supports.
I am trying to subtract 5 minutes from date but its giving unexpected output.
$ date -j -f "%Y/%m/%d %H:%M:%s" -v "-5M" "2021/03/01 09:11:14"
Thu Jan 1 05:25:14 IST 1970
Please suggest the correction.
Converting my comment to answer so that solution is easy to find for future visitors.
This date command should work on BSD date:
date -j -f "%Y/%m/%d %H:%M:%S" -v "-5M" "2021/03/01 09:11:14"
Issue in your command was use of .%s instead of .%S for the second component.
What I intent to get is
$ xxx 2019-10-11 <= insert your command
1570752000
The output is timestamp in Oct 11 00:00:00 UTC 2019. I find a good way to do this in gnu, but not in bsd
This should work:
date -j -f '%F %T %Z' '2019-10-11 00:00:00 U' '+%s'
-j is for dry-run; i.e it prevents date from changing system date and time,
-f is for specifying input format,
+%s is for converting given date to seconds since Epoch.
On NetBSD the following will work:
TZ=GMT0 date -d '2019-10-11 00:00:00' '+%s'
Note the use of the TZ environment variable to specify the input timezone instead of trying to have it parsed from the input (though it may be possible to have a more properly formatted timezone parsed from the input, though then that leaves the question of what timezone the output should be formatted in).
On MacOS you might try something similar to what Oguz suggested:
TZ=GMT0 date -j -f '%Y-%m-%d %H:%M:%S' '2019-10-11 00:00:00' '+%s'
I am new to shell scripting..
I want a script to get any date as a input from user and print date of 3 days back?
example:
If user enters date as 2013-01-01
then output should be
2012-12-29.
If you have GNU date, then this will work:
user_date=2013-01-01
date +%Y-%m-%d -d "$user_date - 3 days"
With BSD date, you'd have to do like this:
user_date=2013-01-01
date -j -v -3d +%Y-%m-%d -d "${user_date//-}0000"
because BSD date needs date to be in the format YYYYmmddHHMM.
I don't have a Solaris now to test there. If you're in Solaris then hopefully there is gdate, and you can use the first option, just replace the date command with gdate.
Whichever OS you are in, there are two important points:
In what format can you pass dates to the date command. I tested that GNU date can accept YYYY-mm-dd format (and probably many others), while BSD needs YYYYmmddHHMM.
In what format can you ask for a difference. With GNU date simply DATE - 3 days works, with BSD date it's trickier with -j -v -3d flags.
man date of your system should help you get through these hurdles. In the worst case, you could do all the date operations you need in perl or similar.
You can just do:
date --date="3 days ago"
to get get date of 3 days back.
In a Bash script, I want to print the current datetime in ISO 8601 format (preferably UTC), and it seems that this should be as simple as date -I:
http://ss64.com/bash/date.html
But this doesn't seem to work on my Mac:
$ date -I
date: illegal option -- I
usage: date [-jnu] [-d dst] [-r seconds] [-t west] [-v[+|-]val[ymwdHMS]] ...
[-f fmt date | [[[mm]dd]HH]MM[[cc]yy][.ss]] [+format]
And indeed, man date doesn't list this option.
Anyone know why this is, or any other (easy) way for me to print the date in ISO 8601 format? Thanks!
You could use
date "+%Y-%m-%d"
Or for a fully ISO-8601 compliant date, use one of the following formats:
date -u +"%Y-%m-%dT%H:%M:%SZ"
Output:
2011-08-27T23:22:37Z
or
date +%Y-%m-%dT%H:%M:%S%z
Output:
2011-08-27T15:22:37-0800
In GNU date date -I is the same as date +%F, and -Iseconds and -Iminutes also include time with UTC offset.
$ date +%F # -I or +%Y-%m-%d
2013-05-03
$ date +%FT%T%z # -Iseconds or +%Y-%m-%dT%H:%M:%S%z
2013-05-03T15:59:24+0300
$ date +%FT%H:%M # -Iminutes or +%Y-%m-%dT%H:%M%z
2013-05-03T15:59+0300
-u is like TZ=UTC. +00:00 can be replaced with Z.
$ date -u +%FT%TZ
2013-05-03T12:59:24Z
These are also valid ISO 8601 date or time formats:
20130503T15 (%Y%m%dT%M)
2013-05 (%Y%m)
2013-W18 (%Y-W%V)
2013-W18-5 (%Y-W%V-%u)
2013W185 (%YW%V%u)
2013-123 (%Y-%j, ordinal date)
2013 (%Y)
1559 (%H%M)
15 (%H)
15:59:24+03 (UTC offset doesn't have to include minutes)
These are not:
2013-05-03 15:59 (T is required in the extended format)
201305 (it could be confused with the YYMMDD format)
20130503T15:59 (basic and exteded formats can't be mixed)
A short alternative that works on both GNU and BSD date is:
date -u +%FT%T%z
The coreutils package provides GNU versions of tools. To install:
$ brew install coreutils
You can see what's provided:
$ brew list coreutils
Notice it comes with date:
$ brew list coreutils | grep date
This is the standard GNU date command so it'll take the -I switch:
$ gdate -I
2016-08-09
Just use normal date formatting options:
date '+%Y-%m-%d'
Edit: to include time and UTC, these are equivalent:
date -u -Iseconds
date -u '+%Y-%m-%dT%k:%M:%S%z'
Taking the other answers one step further, you could add a function to your ~/.bashrc or ~/.zshrc to add the date -I flag:
date() {
if [ "$1" = "-I" ]; then
command date "+%Y-%m-%dT%H:%M:%S%z"
else
command date "$#"
fi
}
It's not a feature of Bash, it's a feature of the date binary. On Linux you would typically have the GNU coreutils version of date, whereas on OSX you would have the BSD legacy utilities. The GNU version can certainly be installed as an optional package, or you can roll your own replacement - I believe it should be a simple one-liner e.g. in Perl.
There's a precompiled coreutils package for Mac OS X available at:
http://rudix.org/packages-abc.html#coreutils.
I regularly use 'date -I' in Linux when saving files. ex: touch x.date -I. While the equivalent in MacOS is 'date +%F', it is a bit awkward to type every time I save a file. So, I set an alias "alias dt='date +%F'" then touch x.dt gives me the date.