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# 29  
Old 09-06-2006
Quote:
Originally Posted by rosh0623
Hi

I donno if I made myself clear here...

when I am using the following statement in a shell script, Though the file exists, this command is failing.. thats because I guess $NF is being considered as a variable..

final_file=`find . -name \*$file_name.* | xargs ls -lt | nawk '/$month $dd/ { print $NF }' | cut -f2 -d "/"`

in a folder I have same filenames with different dates... so I need to pull up a file with a combination of filename and date..

that was my issue... can i get a suggestion as how to go abt ??

Thanks,
Ronnie

Actually it's not because $NF is being treated as a variable, it is because $month and $dd are not.
# 30  
Old 09-07-2006
hey
Quote:
Originally Posted by reborg
Actually it's not because $NF is being treated as a variable, it is because $month and $dd are not.
Hey, the $month has values as Jan till Dec (depending on the input) and $dd has 1 to 31 (again depending on the input).. So is they do have values what would be the problem?..

If I execute this same statement at the command prompt. Its working perfectly fine..
# 31  
Old 09-07-2006
Quote:
Originally Posted by rosh0623
Hey, the $month has values as Jan till Dec (depending on the input) and $dd has 1 to 31 (again depending on the input).. So is they do have values what would be the problem?..
the problem is that you're assuming that '$month' and '$dd' are the environment variables and you think you're treating them the same inside 'awk' surrounded to double-quotes.

that's not how 'awk' works. 'awk' think you're referencing field num 'month' by doing '$month'. the value of 'month' does not get set anywhere and is assumed to be '0'.

What [I think] you need:
Code:
.... | nawk -v myMonth="${month}" -v myDD="${dd}" 'BEGIN {str = myMonth " " myDD} str ~ $0 { print $NF }' | ....

Quote:
Originally Posted by rosh0623
If I execute this same statement at the command prompt. Its working perfectly fine..
# 32  
Old 09-07-2006
Quote:
Originally Posted by vgersh99
the problem is that you're assuming that '$month' and '$dd' are the environment variables and you think you're treating them the same inside 'awk' surrounded to double-quotes.

that's not how 'awk' works. 'awk' think you're referencing field num 'month' by doing '$month'. the value of 'month' does not get set anywhere and is assumed to be '0'.

What [I think] you need:
Code:
.... | nawk -v myMonth="${month}" -v myDD="${dd}" 'BEGIN {str = myMonth " " myDD} str ~ $0 { print $NF }' | ....

Hey, that worked sir !!

I just took out "str ~ $0" and it was working fine...
Thanks a bunch
# 33  
Old 09-07-2006
hi vgersh99

could u give a brief detail of how ur command is actuall working..

Regards
# 34  
Old 09-07-2006
Quote:
Originally Posted by rosh0623
Hey, that worked sir !!

I just took out "str ~ $0" and it was working fine...
Thanks a bunch
interesting......
that was the whole point of 'jumping through these hoops' so that you could get ONLY the files for a specific date.
# 35  
Old 09-07-2006
Quote:
Originally Posted by rochitsharma
hi vgersh99

could u give a brief detail of how ur command is actuall working..

Regards
Code:
nawk -v myMonth="${month}" -v myDD="${dd}" 'BEGIN {str = myMonth " " myDD} str ~ $0 { print $NF }'

  1. pass the env. variables [month and dd] as variables into 'nawk' using the '-v' spec
  2. build the 'str' which is a concatination of the passed in variables in the 'BEGIN' block of the 'nawk'
  3. print the LAST field [$NF] of the lines/records that contain the value of the variable 'str'
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