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Does awk ever resolve params ?..

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# 1  
Old 02-25-2009
Does awk ever resolve params ?..
Hi,
Does awk ever resolve params in the search pattern?..
The following awk doesnt know how to resolve ${tables[$j]}$ inside a loop.
Code:
k=`awk '/${tables[$j]}$/ ${graph[$i]}`

The search pattern has ${tables[$j]}$ and I am narrowing down my search with a $ at the end of string.
So...this leaves me with a question on if awk ever resolve the params in the search patterns?...I am sure it resolves in other places...like in this case ${graph[$i]}

Thx !
# 2  
Old 02-25-2009
Quote:
Originally Posted by anduzzi
Hi,
Does awk ever resolve params in the search pattern?..
The following awk doesnt know how to resolve ${tables[$j]}$ inside a loop.
Code:
k=`awk '/${tables[$j]}$/ ${graph[$i]}`

The search pattern has ${tables[$j]}$ and I am narrowing down my search with a $ at the end of string.
So...this leaves me with a question on if awk ever resolve the params in the search patterns?...I am sure it resolves in other places...like in this case ${graph[$i]}

Thx !
what are these: ${tables[$j]}" and "${graph[$i]}"?
Shell variables?
# 3  
Old 02-25-2009
Hi vgersh,
"${tables[$j]}" and "${graph[$i]}" are 2 arrays holding 2 distinct sets of elements like table list and graph list.
A simplified code snippet giving a better idea...

Code:
#! /bin/ksh

count1=`ls -lart P*.ksh | awk '{print $9}' | wc -l`
list1="`ls -lart P*.ksh | awk '{print $9}'`"
set -A graph $list1

count2=`wc -l read_table.dat | awk '{print $1}'`
list2="`cat read_table.dat`"
set -A tables $list2

j=0

while ((j<$count2))
do
  i=0
 while ((i<$count1))
   do
   k=`awk '/ETL_VW_SCHEMA/ && /[.]${tables[$j]}$/ || /EDW_DB_SCHEMA/ && /[.]${tables[$j]}$/' ${graph[$i]}`
       ((i=i+1))
   done
  ((j=j+1))
done

Awk in the inner most loop doesnt resolve ${tables[$j]} during the run time....but no issues with ${graph[$i]}.
Hope this gives a better idea on the problem...

Thx !
# 4  
Old 02-25-2009
Code:
k=`awk -v t="${tables[$j]}" '/ETL_VW_SCHEMA/ && $0 ~ ("[.]" t "$") / || /EDW_DB_SCHEMA/ && $0 ~ ("[.]" t "$")' ${graph[$i]}`

NOTE: as always, if on Solaris, use 'nawk' or '/usr/xpg4/bin/awk' instead of the old 'awk'.
# 5  
Old 02-25-2009
Quote:
Originally Posted by anduzzi
Hi vgersh,
"${tables[$j]}" and "${graph[$i]}" are 2 arrays holding 2 distinct sets of elements like table list and graph list.
A simplified code snippet giving a better idea...

Code:
#! /bin/ksh

count1=`ls -lart P*.ksh | awk '{print $9}' | wc -l`
list1="`ls -lart P*.ksh | awk '{print $9}'`"


Why are you using -l then removing all the details? You are calling 2 unnecessary external commands.

Code:
count1=`ls -art P*.ksh | wc -l`
list1=`ls -art P*.ksh`

Why are you using the -a option? Your pattern cannot match any dot files.

In fact you are using more than 2 UECs:

Code:
set -- P*.ksh
count1=$#
list1=`ls -rt P*.ksh`

Quote:
Code:
set -A graph $list1

count2=`wc -l read_table.dat | awk '{print $1}'`


There's no need for awk:

Code:
count2=$( wc -l < read_table.dat)

Quote:
Code:
list2="`cat read_table.dat`"
set -A tables $list2

j=0

while ((j<$count2))


I recommend using the standard syntax:

Code:
while [ $j -lt $count2 ]

Quote:
Code:
do
  i=0
 while ((i<$count1))
   do
   k=`awk '/ETL_VW_SCHEMA/ && /[.]${tables[$j]}$/ || /EDW_DB_SCHEMA/ && /[.]${tables[$j]}$/' ${graph[$i]}`
       ((i=i+1))


I recommend using the standard syntax:

Code:
i=$(( $i + 1 ))

Quote:
Code:
   done
  ((j=j+1))
done

Awk in the inner most loop doesnt resolve ${tables[$j]} during the run time....but no issues with ${graph[$i]}.

Variables are not expanded inside single quotes.

To pass a shell variable to awk, use the -v option:

Code:
awk -v x="${tables[$j]}" '...'

# 6  
Old 02-25-2009
Hi Johnson/Vgersh,
Thank you very much for the suggestions and the pointers..
But my shell errors out with the awk syntax....here are some quick details on my OS and the actual error itself...I tried switching my shell to ksh and run it but still errors out the same way as mentioned below.

Code:
$ awk -v t="B1_STAT_HIST" '/ETL_VW_SCHEMA/ && $0 ~ ("[.]" t "$")  || /EDW_DB_SCHEMA/ && $0 ~ ("[.]" t "$")' PDEWG300_B1_STAT_HIST.ksh
awk: syntax error near line 1
awk: bailing out near line 1

$ uname -a
SunOS xspetl01 5.8 Generic_117350-36 sun4u sparc SUNW,Sun-Fire-480R

Appreciate your suggestions !
Thx !
# 7  
Old 02-25-2009
Oh sorry....my bad !
nawk works perfect in this case.

Thank you so much for your time..
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