Issue
I have a html file that I process using a bash script and want to remove empty tables. The file is generated from a sql statement, but contains the table header when no records are found. I want to remove the header where no records are found.
<table border="1">
<caption>Table with data</caption>
<tr>
<th align="center">type</th>
<th align="center">column1</th>
<th align="center">column2</th>
<th align="center">column3</th>
<th align="center">column4</th>
</tr>
Data rows exists here
</table>
<table border="1">
<caption>Empty Table To Remove</caption>
<tr>
<th align="center">type</th>
<th align="center">column1</th>
<th align="center">column2</th>
<th align="center">column3</th>
<th align="center">column4</th>
<th align="center">column5</th>
<th align="center">column6</th>
<th align="center">column7</th>
</tr>
</table>
<table border="1">
<caption>Table with data</caption>
<tr>
<th align="center">type</th>
<th align="center">column1</th>
<th align="center">column2</th>
<th align="center">column3</th>
<th align="center">column4</th>
</tr>
Data rows exists here
</table>
I tried to use a combination of grep and sed to remove the empty table. I was able to accomplish this when the tables contained an equal number of columns. I am having issues now that I have tables with a different number of columns.
When the table had an equal number of columns, I was able to loop through based on the caption, do a count and then remove. This is not working since the number of columns vary.
Solution
Like this, using xmlstarlet and xpath:
$ xmlstarlet format -H file.html | sponge file.html
$ xmlstarlet ed -d '//table[./caption/text()="Empty Table To Remove"]' file.html
<?xml version="1.0" standalone="yes"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html>
<body>
<table border="1"><caption>Table with data</caption><tr><th align="center">type</th><th align="center">column1</th><th align="center">column2</th><th align="center">column3</th><th align="center">column4</th></tr>
Data rows exists here
</table>
<table border="1"><caption>Table with data</caption><tr><th align="center">type</th><th align="center">column1</th><th align="center">column2</th><th align="center">column3</th><th align="center">column4</th></tr>
Data rows exists here
</table>
</body>
</html>
To edit in place like sed -i, use
xmlstarlet edit -L ...
Not explained, but don't use sed nor regex to parse HTML/XML
Answered By - Gilles Quénot Answer Checked By - Marilyn (WPSolving Volunteer)