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Shell Programming and Scripting

bash shell script string comparison

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# 1  
Old 04-29-2009
bash shell script string comparison
I want to remove a line that has empty string at second field when I use cut with delimeter , like below
Code:
$cat demo
hello, mum
hello,
 
#!/bin/sh
 
while read line
do
if [ `cut -f 2 -d "," "$line" = "" ]
then
    # remove the current line command goes here
fi
done < "demo"

i got an error message for above command and I have no idea how to remove current line

can I use
Code:
sed 's/$0//'

# 2  
Old 04-29-2009
use something like this

awk -F"," '{ if ($2!=" ") print $0}'
# 3  
Old 04-29-2009
Code:
awk -F, '$2' file > newfile

Regards
# 4  
Old 04-29-2009
I am using if statement and I fixed it to
Code:
if [ `echo $line | cut -f 2 -d","`=="" ]
then
    echo ""
else
    echo $line
fi

but I get an error message below
[: ==: unary operator expected

can any one help me using if statement??
# 5  
Old 04-29-2009

Code:
if [ "`echo $line | cut -f 2 -d","`" = "" ]

Or:

Code:
if [ -z "`echo $line | cut -f 2 -d","`" ]

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