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How to replace part of string?


 
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# 1  
How to replace part of string?

Hi Gurus,

I need to replace part of string in file, the string format is below: I can use ABCD to find string, then replace values after "=" sign

Code:
ABCD_XXX=value
ABCD_YYY=value

after replace
Code:
ABCD_XXX=new_value
ABCD_YYY=new_value

my OS is SunOS 5.10 Generic_150400-64 sun4v sparc sun4v

thanks in advance

Last edited by green_k; 04-23-2019 at 04:30 PM..
# 2  
Hi, you can use an input file with the new key value pairs
Code:
$> cat file1
ABCD_XXX=new_value1
ABCD_YYY=new_value2
$> cat file2
foo
ABCD_XXX=value1
ABCD_YYY=value2
bar=baz

Try:
Code:
awk 'NR==FNR{A[$1]=$2; next} $1 in A{$2=A[$1]}1' FS='=' OFS='=' file1 file2

Output:
Code:
foo
ABCD_XXX=new_value1
ABCD_YYY=new_value2
bar=baz

This User Gave Thanks to Scrutinizer For This Post:
# 3  
Quote:
Originally Posted by Scrutinizer
Hi, you can use an input file with the new key value pairs
Code:
$> cat file1
ABCD_XXX=new_value1
ABCD_YYY=new_value2
$> cat file2
foo
ABCD_XXX=value1
ABCD_YYY=value2
bar=baz

Try:
Code:
awk 'NR==FNR{A[$1]=$2; next} $1 in A{$2=A[$1]}1' FS='=' OFS='=' file1 file2

Output:
Code:
foo
ABCD_XXX=new_value1
ABCD_YYY=new_value2
bar=baz

thanks Scrutinizer. Sorry, I didn't give the sample properly. actually, there is only one value for all lines after equal. I updated my initial query. I tried to use awk command, I can use below command to print out correct result, but not sure how to replace it in file.

Code:
awk -F"=" '/ABCD/ {print $1"=value"}'  file

# 4  
You can redirect the output to a new file. If ok you can replace the old file with the new file:

Code:
nawk -F"=" '/ABCD/ {print $1"=value"}'  file > newfile

This User Gave Thanks to Scrutinizer For This Post:
# 5  
Quote:
Originally Posted by Scrutinizer
You can redirect the output to a new file. If ok you can replace the old file with the new file:

Code:
nawk -F"=" '/ABCD/ {print $1"=value"}'  file > newfile

thanks Scrutinizer.

in the file, it has other contents which need to keep "as is". above command only print the match ones. how can I keep these file content as is.
for example:
old file:

Code:
aaaaaa
bbbbb
ABCD_XXX=value
ccccc

after replace:
Code:
aaaaaa
bbbbb
ABCD_XXX=new_value
ccccc

# 6  
Hi Gurus,
I am able to use below command to get expected result. one more question:
I need to pass variable to this command, somehow it doesn't work.

Code:
awk -F"=" '!/ABCD/ {print $0}; /ABCD/ {print $1"=NEW_VALUE"}'  file > new_file

I use below command, it throw out error.
Code:
awk -F"=" -v var="$new_value" '!/ABCD/ {print $0}; /ABCD/ {print $1"=${var}"}'  file > new_file


Last edited by vgersh99; 04-23-2019 at 07:48 PM..
# 7  
Quote:
Originally Posted by green_k
Hi Gurus,
I am able to use below command to get expected result. one more question:
I need to pass variable to this command, somehow it doesn't work.

Code:
awk -F"=" '!/ABCD/ {print $0}; /ABCD/ {print $1"=NEW_VALUE"}'  file > new_file

I use below command, it throw out error.
Code:
awk -F"=" -v var="$new_value" '!/ABCD/ {print $0}; /ABCD/ {print $1"=${var}"}'  file > new_file

simplified and fixed:
Code:
awk -F= -v var="$new_value" '/ABCD/ {$1= "=" var} 1' file > new_file

These 2 Users Gave Thanks to vgersh99 For This Post:

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