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awk - change variable on fly

 
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# 1  
Old 04-20-2012
awk - change variable on fly
Hello All,

I have csv file, where one of fields is date (yyyy/mm/dd 00:00:00). Using awk I am trying to find all records with date newer/older than specific date. My idea was to compare unix timestamps of both dates:
Code:
start=`date +%s -d "$DateStart"`
awk -v start="$start" -v current=`date +%s -d $10` 'current < start' file.csv > temp.file

However awk dont "see" variable $10. Is there any way to pass value from this field to date command?

Thank you in advance for any tips.

Kind regards,
# 2  
Old 04-20-2012
Hi, try ${10}
# 3  
Old 04-20-2012
Thank you for (very) quick reply Smilie

I tried:
Code:
awk -v start="$start" -v current=`date +%s -d ${10}` 'current < start' file.csv > temp.file

But I receive:
Code:
date: option requires an argument -- 'd'
Try `date --help' for more information.

Maybe I should use something like below (pseudo-code):
Code:
awk -v start="$start" 'system("date +%s -d $10") < start' file.csv > temp.file

?
Last edited by haczyk; 04-20-2012 at 08:42 AM.. Reason: Add tags
# 4  
Old 04-20-2012
try the system() call in awk
[code
start=`date +%s -d "$DateStart"`
awk -v start="$start" 'system("date +%s -d " $10) < start' file.csv > temp.file
[/code]
# 5  
Old 04-20-2012
Using "system" I have error:
Code:
date: extra operand `00:00:00'
Try `date --help' for more information.

But I see where is an issue....Unlucky $10 must be in double qoutas:
#date +%s -d "2008/12/20 00:00:00"
1229727600
# date +%s -d 2008/12/20 00:00:00
date: extra operand `00:00:00'
Try `date --help' for more information.
#

Hm...so how can I surround this variable with double quotas? This is not working:
Code:
awk -v start="$start"  'system("date +%s -d " "$10") < start' file.csv > temp.file

Thank you Jim for hint.
# 6  
Old 04-20-2012
OK, now I get it, you were not trying to use shell variable ${10}, but awk variable $10. Check if $10 does indeed contain the date. If so, you would need something like this (not tested), but test if yyyy/mm/dd is the right format for -d.
Code:
awk -v start="$start" '{"date +%s -d "$10 | getline current} current < start' file.csv > temp.file

Edit: so if time is in $11, then that would be something like:
Code:
awk -v start="$start" '{"date +%s -d \"" $10 " " $11 "\"" | getline current} current < start' file.csv > temp.file

Last edited by Scrutinizer; 04-20-2012 at 09:12 AM..
# 7  
Old 04-20-2012
Yes, exactly - I need use awk variable ..in strange way :d

In my case field "$10" contains for example"2008/12/20 00:00:00" - thats why I need to put this field in double quotas.
@Scrutinizer Thank you for help. I modifed your command into this:
Code:
awk -v start="$start" '{"date +%s -d \""$10"\"" | getline current} current > start' file.csv > temp.file

All looks fine, but at the end I have:
Code:
/bin/sh: Syntax error: Unterminated quoted string

Did I miss something ?
 
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