home-grown ntp

I want to write a script to set the time from time.gov, but the date command doesn't want to read the results of the script to fetch the time.

contents of the myntp.sh

wget -o /dev/null http://www.time.gov/timezone.cgi?Eastern/d/-5 -O - | html2text | grep ..\:.. | sed 's/ //g'

I've tried using pipes, backquotes, and input redirection from a file.

./myntp.sh | date --set=

date --set=`./myntp.sh`

./myntp.sh > /tmp/time
date --set=</tmp/time

Is there a way to make this work?

Would something like this work?
/usr/sbin/ntpdate 128.118.25.3; hwclock --systohc

Have you tried breaking up the commands in the script up and using echo statements (and use /bin/bash -x as the interpreter) to see what each step is returning? The individual commands look OK, although I'd use the following to grep the output:

grep -E '[[:digit:]]{2}:[[:digit:]]{2}:[[:digit:]]{2}'

As an alternative, can you use ntpdate?

Wow, two posts in less than an hour! Tangle the ntp command worked great. gilead, I'm a bit confused about the individual commands and echo part, but here's what I get running the commands individually then adding the next command to the pipe:

The wget part outputs the raw html code
html2txt formats the raw html into what the page looks like when viewed in links
grep returned " hh:mm:ss" (filled in with the time)
(when I tried grep -E '[[:digit:]]{2}:[[:digit:]]{2}:[[:digit:]]{2}' I got ""
and sed just got rid of the extra spaces

The error messages I got with my date commands are:

date: invalid date `2\b20\b0:\b:4\b47\b7:\b:4\b44\b4'
and with sh -x: /bin/date: /bin/date: cannot execute binary file

In the future I think I will use ntpdate, but I'm still interested in why date isn't accepting my input.

I ran your first script like this:

wget -o /dev/null http://www.time.gov/timezone.cgi?Eastern/d/-5 -O - | html2text | grep ..\:.. | sed 's/ //g' | od -c
0000000 2 \b 2 0 \b 0 : \b : 4 \b 4 7 \b 7 :
0000020 \b : 2 \b 2 0 \b 0 \n
0000031

Does the backspacing and overtyping screw up your results?

wget -o /dev/null http://www.time.gov/timezone.cgi?Eastern/d/-5 -O - | html2text | grep ..\:.. | sed -e 's/ //g' -e 's/^B.//'

nope, wget -o /dev/null http://www.time.gov/timezone.cgi?Eastern/d/-5 -O - | html2text | grep ..\:.. | sed -e 's/ //g' -e 's/^B.//' still gives the same results

but the od -c give different results than your does when I enter wget -o /dev/null http://www.time.gov/timezone.cgi?Eastern/d/-5 -O - | html2text | grep ..\:.. | sed 's/ //g' | od -c (is this is expected?)

output of my od -c

0000000   2  \b   2   1  \b   1   :  \b   :   1  \b   1   2  \b   2   :
0000020  \b   :   4  \b   4   0  \b   0  \n
0000031

output off diff tmp tmp2 (tmp2 is copied from jschiwal's post)

1,2c1,2
< 0000000   2  \b   2   1  \b   1   :  \b   :   0  \b   0   8  \b   8   :
< 0000020  \b   :   1  \b   1   8  \b   8  \n
---
> 0000000 2 \b 2 0 \b 0 : \b : 4 \b 4 7 \b 7 :
> 0000020 \b : 2 \b 2 0 \b 0 \n

Thank you both for pointing out the weird output. I didn't have html2text installed so I couldn't see anything wrong with the grep I posted earlier. I installed it, got the control codes, etc. and breathed a sigh of relief...

For the control character in the sed filter "-e 's/^B.//', I typed it by pressing Cntrl-v Cntrl-b. It isn't the literal characters '^B'. Nevertheless, it's wrong all the same. It should be [Cntrl]-v[Cntrl-h.
And the substitution should be done globally on the line.
"-e 's/^H//g'"

wget -o /dev/null http://www.time.gov/timezone.cgi?Eastern/d/-5 -O - | html2text | grep ..\:.. | sed -e 's/ //g' -e 's/'^H'.//g' | od -c
0000000 0 0 : 2 0 : 0 4 \n
0000011

It worked! I just added backquotes to the '^H' (typed as ctrl+v, ctrl+h)version of the script and it corrected the clock. I guess I need to brush up on my control and escape characters

Thanks

The [Cntrl]-v [Cntrl]-<key> sequence also works in vim.