My date command is not working

rajivswe.2k7 · 04-10-2013, 03:34 AM

I am running the below command and got the below error.Please advise.

echo -n "20130301_0050" |sed -e 's/_/ /'|xargs -0 date -d "{}" +%s

ERROR: date: extra operand `20130301 0050'

druuna · 04-10-2013, 03:55 AM

Is this what you are after:

Code:

echo -n "20130301_0050" | sed 's/_/ /' | xargs -0 -I '{}' date -d '{}' +%s

Result of one liner: 1362095400

rajivswe.2k7 · 04-10-2013, 04:58 AM

Its working.Thank you.

rajivswe.2k7 · 04-10-2013, 05:11 AM

I would like to add 14400 seconds in the output.I have tried the same way,but its not working.Please advise.

[rgandhi@CF-08-2-15 ~]$ echo -n "20130301_0050" | sed 's/_/ /' | xargs -0 -I '{}' date -d '{}' +%s|xargs -0 -I '{}' `expr '{}' + 14400`
expr: non-numeric argument

rajivswe.2k7 · 04-10-2013, 05:54 AM

I have achieved this way. Please advise any other better way to do.
date='20130301_0050'

check_date=$(echo -n "${date}" | sed 's/_/ /' | xargs -0 -I '{}' date -d '{}' +%s|while read f; do echo `expr ${f} - 14400`;done| xargs -0 -I '{}' date -d @'{}' "+%Y%m%d_%H%M")

Thank you.

druuna · 04-10-2013, 05:56 AM

What are you actually trying to accomplish? I'm not talking about specifics, but the general problem.

It seems that you are trying to use an elaborate scheme for something that might be accomplished in a simpler more elegant way.

BTW: expr should be avoided (use awk, bc or bash itself to do arithmetic)

Here are a few links that address the arithmetic issue's:
- Bash Math
- Arithmetic in Bash
- Perform arithmetic operations

These general links might be useful:

Bash:

Sed and Awk:

O'Reilly: Sed/Awk

rajivswe.2k7 · 04-10-2013, 06:01 AM

Thank you.I am new to shell script.I tried to add 4 hrs to a date 20130301_0050 and then tried to convert into same format like 20130301_0450.

Thanks again for the material links...

millgates · 04-10-2013, 06:38 AM

Hi, how about

Code:

mydate=20130301_0050
date -d "${mydate//_/ } + 4 hours" +%Y%m%d_%H%M

rajivswe.2k7 · 04-10-2013, 07:35 AM

Thank you soo much.Its working as expected.