Man page of date will give you more info than anything else, it is a very descriptive one.
I wanted to hightlight few of the options used and thier alternatives, mainly the option "-d". Why because it looks like solaris version of date does not have "-d" option.
The man page says
-d, --date=STRING
display time described by STRING, not `now'
Lets take few examples
Firing the date command would give you the date
Code:
root@bt > date Wed Jan 4 07:52:17 IST 2012
Do you want to customize this? No problem. Use the format control. There are like more than 20 format control options.
Say, you want the date in DD/MM/YYYY format
Code:
root@bt > date '+%d/%m/%Y' 04/01/2012
%d day of month (e.g, 01)
%m month (01..12)
%Y year
Want the current date in seconds since the epoch? Use "+%s" option
Code:
root@bt > date '+%s' 1325644010
%s seconds since 1970-01-01 00:00:00 UTC
As you can see, "+" is mandatory which is followed by the format specifier.
To set/change the system date, use the "-s" option.
-s, --set=STRING
set time described by STRING
Code:
root@bt > date Wed Jan 4 08:21:47 IST 2012 root@bt > date -s "Mon Dec 31 00:00:00 IST 1990" Mon Dec 31 00:00:00 IST 1990 root@bt > date Mon Dec 31 00:00:01 IST 1990
Now, what does "-d" option do? Hmmm, if you see we were dealing with current system date till now. What if you want to do the same with some other date? Well, that is where "-d" option comes to the rescue!
Say, you want to find the seconds since epoch till December 31 1990
Code:
root@bt > date -d "Dec 31 1990" '+%s' 662581800
You want to format a date given to you in "31 Dec 1990" to MM-DD-YY
Code:
root@bt > date -d "31 Dec 1990" '+%m-%d-%y' 12-31-90
Cool right? Now, the "-d" option is not available in Solaris (not sure about 10 though).
Here is an alternative in awk for achieving the above
To get the time in seconds
Code:
root@bt > echo "Dec 31 1990" | nawk 'BEGIN{month="JanFebMarAprMayJunJulAugSepOctNovDec"}
{ print mktime($3" "int((index(month,$1)/3))+1" "$2" 00 00 00") }'
662581800
Code:
root@bt > echo "31 Dec 1990" | nawk 'BEGIN{month="JanFebMarAprMayJunJulAugSepOctNovDec"}
{ print int((index(month,$2)/3))+1"-"$1"-"substr($3,3) }'
12-31-90
We can practically do anything in awk! Check the right side link for AWK tutorial.
One more thing before we go, how do we convert the seconds to date?
Say, I have 662581800 (from our previous example), I want to convert it to actual date format
Code:
root@bt > date -d @662581800 Mon Dec 31 00:00:00 IST 1990
Note the "@" symbol before the seconds.
Also note that I have used nawk instead of awk, because in solaris the awk version is pretty old and it is kind of useless. Either use "nawk" or awk from this path "/usr/xpg4/bin/awk" in solaris.
Good Day!
