Getting syntax error exception for “expr”

Question

I have an xml file which looks like below

INPUT XML FILE

<ReconSummary> <entryName>Total Deep</entryName> <Code>777</Code> <License>L</License> <Tran>H20</Tran> <job>1234</job> </ReconSummary> <ReconSummary> <entryName>Total Saurav</entryName> <Code>666</Code> <License>L</License> <Tran>H20</Tran> <job>1234</job> </ReconSummary> <ReconSummary> <entryName>Total Ankur</entryName> <Code>555</Code> <License>L</License> <Tran>H20</Tran> <job>1234</job> </ReconSummary> 

I was trying to search the pattern "Total Deep" and after that i want to comment out the the tag after 3rd or 4th line of the matching pattern in xml file

My code is below

while read -r line do; LineNum=`grep -n "Total Deep" input.xml | cut -d: -f 1` TOTAL=`expr $LineNum + 4` echo $LineNum echo $TOTAL done < file.txt 

While executing the code i am getting below exception

expr: syntax error 

Can anyone tell me what is wrong in this code?

Answer 1

Your issue is that grep returns multiple line matching your expression. What you end up executing with expr is something like expr 1 3 4 + 4 (if there are matches on lines 1, 3, and 4). This is where your syntax error comes from.

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From comments, it is clear that you want to comment out a particular child node from a particular ReconSummary node. If you had wanted to delete e.g. the job node, I would have suggested using

xmlstarlet ed -d '//ReconSummary[entryName = "Total Deep"]/job' file.xml >newfile.xml 

... but commenting out rather than deleting is a bit more tricky.

Similar to an answer to your previous question that I wrote just moments ago, this would be done with an XSL transformation:

<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:template match="/|node()|@*"> <xsl:copy> <xsl:apply-templates select="node()|@*"/> </xsl:copy> </xsl:template> <xsl:template match="//ReconSummary[entryName = 'Total Deep']/job"> <xsl:text disable-output-escaping="yes">&lt;!-- </xsl:text> <xsl:copy-of select="."/> <xsl:text disable-output-escaping="yes"> --&gt;</xsl:text> </xsl:template> </xsl:transform> 

The XPATH query //ReconSummary[entryName = 'Total Deep']/job matches the job child node of the ReconSummary node whose entryName child node has the value Total Deep.

You can change this easily to instead comment out the Tran node. The XPATH query for that would be

//ReconSummary[entryName = 'Total Deep']/Tran` 

To match both the job and the Tran node, use

//ReconSummary[entryName = 'Total Deep']/*[name()='job' or name()='Tran'] 

As in my previous answer, you would apply this XSL transformation to your XML file using either of

xmlstarlet tr transform.xsl file.xml >newfile.xml 

or

xsltproc transform.xsl file.xml >newfile.xml 

where you file is file.xml and the transformation is stored in transform.xsl.