CODEWITHSUNDEEP
bashreplace
Filip
Filip

Reputation: 23

Bash command to search for a string in file and replace the value with value from another file

I have two files file a.) xmlFile.xml b.) emails.txt

xmlFile.xml has the following structure repeated multiple times

<gname>Office</gname>
<uname>person</uname>

emails.txt has list of email addresses

[email protected]
[email protected]
...

What I want to accomplish is to replace "person" in xmlFile.xml with subsequent value taken from emails.txt

I have tried

# while read email ; do sed  "s/person/$email/g" xmlFile.xml > xmlFile.new; done < emails.txt

However I endup with file that has all "person" values replaced with the last email from emails.txt

Thanks, Filip

Upvotes: 2

Views: 905

Answers (3)

mitma
mitma

Reputation: 1

Here's how to do it using bash & xmlstarlet!

IFS=$'\n' read -r -d "" -a array < emails.txt                   # read file with email addresses into array
n=$(xmlstarlet sel -T -t -v "count(//uname)" -n xmlFile.xml)    # count "uname" nodes in XML file
xmlFileStr="$(< xmlFile.xml)"                                   # read XML file into variable


if [[ $n -eq ${#array[@]} ]]; then   # if the number of nodes & email addresses is equal ...
   for ((i=1; i <= ${n}; i+=1)); do
      xmlFileStr="$(printf '%s' "$xmlFileStr" | xmlstarlet ed -P -t -u "//uname[${i}]" -v "${array[$((i-1))]}")"
   done
fi

printf '%s\n' "$xmlFileStr" > xmlFile.xml
cat xmlFile.xml

Upvotes: 0

Dennis Williamson
Dennis Williamson

Reputation: 360085

One way to accomplish this would be to use in-place editing:

while read email ; do sed -i "s/person/$email/;q" xmlFile.xml; done < emails.txt

If there's little or nothing more to the XML file than what you've show, just reconstruct it:

sed -e 'i <gname>Office</gname>' -e 's|.*|<uname>&</uname>|' emails.txt > newxmlFile.xml

without even touching the existing xmlFile.xml.

However, you should probably use an XML parser such as xmlstarlet.

Upvotes: 1

SiegeX
SiegeX

Reputation: 140327

awk 'NR==FNR{e[i++]=$0;next} /person/{sub("person",e[j++])}1' emails.txt xmlFile.xml

Explanation

  1. NR==FNR: This is only true when awk is reading the first file. It essentially tests total number of records seen (NR) vs the input record in the current file (FNR).
  2. e[i++]=$0: Create an array named e who's index increments by 1 (i++)and who's value is equal to the current record $0. This array will hold our emails
  3. next: Ignore the rest of the script if this is reached, start over with a new input record
  4. /person/: Only perform the subsequent code if the current record matches the regex "person"
  5. sub("person",e[j++]): Substitute the literal value "person" for a value in our array e that we created earlier. Increment this array j++ for the next record we match
  6. 1: Always returns true, essentially a shortcut for {print $0}, or output our current record

Proof Of Concept

$ cat emails.txt
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]

$ cat xmlFile.xml
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>
<gname>Office</gname>
<uname>person</uname>

$ awk 'NR==FNR{e[i++]=$0;next} /person/{sub("person",e[j++])}1' emails.txt xmlFile.xml
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>
<gname>Office</gname>
<uname>[email protected]</uname>

The above script assumes that person is a literal value. If it is not, then..

Replace: /person/{sub("person",emails[j++])}
With: /<uname>/{sub(".*","<uname>"emails[j++]"</uname>")}

Upvotes: 3

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