[SOLVED] Undocumented options of date command and other commands

Mr. ameya sathe · 08-11-2009, 02:39 PM

The other day; I was fiddling with options of `date' command. I found out an option of -I with it. But; this option is not documented anywhere in the man pages & info pages. Google is also not easily yielding result about it.

Code:

date -I

Any pointers for the date -I command.

David the H. · 08-11-2009, 08:02 PM

Well, the only thing I could find was this:

http://www.mail-archive.com/bug-core.../msg06084.html

Which suggests that it's a deprecated option, and so will probably disappear sometime in the future.

Kenhelm · 08-12-2009, 12:54 AM

'-I' is on this 2004 man page
http://www.linuxmanpages.com/man1/date.1.php

Code:

-ITIMESPEC, --iso-8601[=TIMESPEC]

     output date/time in ISO 8601 format.
     TIMESPEC=`date' for date only, `hours', `minutes', or
    `seconds' for date and time to the indicated precision.
     --iso-8601 without TIMESPEC defaults to `date'.

Code:

# Examples in British Summer Time (= Greenwich Mean Time +0100)

date -I
2009-08-12

date -Idate
2009-08-12

date -Ihours
2009-08-12T04+0100

date -Iminutes
2009-08-12T04:02+0100

date -Iseconds
2009-08-12T04:03:26+0100

# Some versions of 'date' can give nano seconds
date -Ins
2009-08-12T04:04:20,582835176+0100

# d,h,m,s,n can be used instead of date,hours,minutes,seconds,ns

junust · 08-12-2009, 06:23 AM

By the way, the same like `date -I` info you will receive if issue command `date` on checkpoint secure plat firewall, where is the really `date` command info you will see if type /bin/date