CODEWITHSUNDEEP
xmlbashsed
ajay_t
ajay_t

Reputation: 2385

Un-commenting xml block using sed command

I have xml file which has many elements commented. From all of these elements, I want to uncomment one element using sed command.

I have xml file as:

<!-- This is the sample xml
    which holds the data of the students -->
<Students>
    <!-- <student>
        <name>john</>
        <id>123</id>
    </student> -->
    <student>
        <name>mike</name>
        <id>234</id>
    </student>
    <!-- <student>
        <name>NewName</name>
        <id>NewID</id>
    </student> -->
</Students>

In the above xml file, I want uncomment the last xml block, so my file will look like

<!-- This is the sample xml
    which holds the data of the students -->
<Students>
    <!-- <student>
        <name>john</>
        <id>123</id>
    </student> -->
    <student>
        <name>mike</name>
        <id>234</id>
    </student>
    <student>
        <name>NewName</name>
        <id>NewID</id>
    </student> 
</Students>

I gone through the sed command, but didn't get how can delete just <!-- and --> from last block. Is it possible to uncomment xml block with <name> as NewName ? I didn't find any thing apart from deleting whole line.

EDIT: I can have many xml elements other than <name> and <id> like <address>, <city>, <class>,<marks>.

Upvotes: 2

Views: 1709

Answers (2)

potong
potong

Reputation: 58473

This might work for you (GNU sed):

sed -r '/<Students>/,/<\/Students>/{/<Students>/{h;d};H;/<\/Students>/!d;g;s/(.*)<!-- (.*) -->(.*)/\1\2\3/}' file

This stores the Students data in the hold space then uses greed to find the last occurence of <!-- and --> and removes them before printing the data.

Upvotes: 1

Tomalak
Tomalak

Reputation: 338288

Don't use sed. Use xsltproc.

<!-- uncomment.xsl -->
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <!-- this copies every input node unchanged -->
  <xsl:template match="node() | @*">
    <xsl:copy>
      <xsl:apply-templates select="node() | @*" />
    </xsl:copy>
  </xsl:template>

  <!-- this uncomments every comment that starts with a `<` -->
  <xsl:template match="comment()[substring(normalize-space(), 1, 1) = '&lt;']">
    <xsl:value-of select="." disable-output-escaping="yes" />
  </xsl:template>
</xsl:stylesheet>

on the command line:

xsltproc -o output.xml uncomment.xsl input.xml

If it works correctly, you get this for your input XML:

<!-- This is the sample xml
    which holds the data of the students -->
<Students>
    <student>
        <name>john</name>
        <id>123</id>
    </student>
    <student>
        <name>mike</name>
        <id>234</id>
    </student>
    <student>
        <name>NewName</name>
        <id>NewID</id>
    </student>
</Students>

Upvotes: 2

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