[SOLVED] sed unterminated `s' command

random0munky · 08-19-2011, 11:09 AM

Hi,

I searched through the forums and google to try and find a resolution to my particular issue, but unfortunately I haven't been able to come across one. Here's what I have right now:

Code:

echo -e "Count\tDate\tHour"

for line in `cat ./report_activity | grep session_completed | awk '{ print $3 }'`
do
 # count
 Count=0
 # date
 Date=`echo $line | sed s/[//`
 echo $Date
 # hour
done

What the line reads after I cat and grep it out:
[17/Aug/2011:14:15:46
Trying to remove the front box parens.

Thanks

random0munky

acid_kewpie · 08-19-2011, 11:15 AM

if you're looking for a literal [ then escape it. Date=`echo $line | sed -e 's/\[//'`

btw, don't use `backticks`, use $(parenthesis) instead, it's much clearer and more powerful.

thinknix · 08-19-2011, 11:16 AM

You want:

Code:

Date=`echo $line | sed -e 's/\[//'`

Adding a '-e', wrapping the entire sed expression in single quotes, and escaping the left-bracket, as it would normally be interpreted as the start of a regular expression character class. Edit to add - the '-e' isn't strictly necessary with one expression. The end result is the same.

random0munky · 08-19-2011, 11:20 AM

Ah thank you very much. How would I use the same line without backticks. If possible, can you link me a page on how it's more powerfule << linux script noobie here just starting to learn

Thanks

random0munky

acid_kewpie · 08-19-2011, 11:33 AM

you just replace the backticks with $( at the start, and ) at the end. One of the best things is that as the start is diffrent to the end, you can next them... "$(command_one -a -b $(command_two) -c -d )" etc...

random0munky · 08-19-2011, 11:36 AM

Ah that's pretty cool with having nested commands and if piping isn't a viable option. Thanks. I'll look more into using that syntax. Do you happen to know if using the $( command ) vs ` command ` is more resource intensive than the other?

random0munky

Quote:

Originally Posted by acid_kewpie

you just replace the backticks with $( at the start, and ) at the end. One of the best things is that as the start is diffrent to the end, you can next them... "$(command_one -a -b $(command_two) -c -d )" etc...

acid_kewpie · 08-19-2011, 11:37 AM

no, it's just a newer syntax (well, a decade +) no overheads.

random0munky · 08-19-2011, 11:43 AM

Ah gotcha gotcha. Thanks mate. I'll be sure to remember this and thanks everyone for the help =) Greatly appreciated

random0munky

Quote:

Originally Posted by acid_kewpie

no, it's just a newer syntax (well, a decade +) no overheads.