How to extract string between two specified characters and end of line?


 
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# 15  
Old 03-05-2020
Code:
sed -n "s/$key/$value/gp" $input

only prints lines where a substitution occurred.

But it won't print any existing lines that have not be substituted.
The following bash-4 script is a universal fix:
Code:
#!/bin/bash
# bash 4+ or ksh 93+ required

input=test.txt

# aa[] is an associative (string-indexed) array
typeset -A aa
#declare -A aa # is bash-only

# loop through the key/value file, store in aa[]
while IFS="=" read key value
do
  aa[$key]=$value
done < bbb.txt

# loop through the target file, do not split on whitespace
while IFS= read line
do
  # for each $line
  # loop through the array(-indices)
  for key in "${!aa[@]}"
  do
    # get the corresponding value
    value=${aa[$key]}
    # do the substitutions $key -> $value
    line=${line//$key/$value}
  done
  # printf is more robust than echo
  printf "%s\n" "$line"
done < $input

I have put some comments that explain how it works.
Compared to the sed solution that processes the input file many times, this solution causes less I/O (but uses more memory: the whole bbb.txt file must fit into memory).
It even fixes the potential problem that the values may not contain a / character because it clashes with the / dividers in sed.
# 16  
Old 03-05-2020
Thanks @MadeInGermany . It did the trick and gave the expected output.
# 17  
Old 03-19-2020
Once again - code tags!

Hi,

the code is working for $$values that has a . after it or end of line. In case I have the record as below it is not replacing it.

Code:
$$WF_PRM_TARGET_extract_$$WF_PRM_SOURCE.$$WF_PRM_DIVISION.dat

.Here only $$WF_PRM_DIVISION is getting replaced

I tried this <
Code:
sed '/.*\$\$/ { s///; s/\..*//; s/\._*//; }' test.txt > aaa.txt

/>
Moderator's Comments:
Mod Comment
Please use code tags when posting data and code samples!


--- Post updated at 06:29 PM ---

<code>
sed '/.*\$\$/ { s///; s/\..*//; s/\._*//; }' test.txt > aaa.txt
</code>
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