How can I print sheetnames of a spreadsheet using Linux command-line?

in2csv from the csvkit package provides the --names or -n option for that: ^[Source]

 -n, --names     Display sheet names from the input Excel file.

In your example the command would be:

in2csv -n file1.xls

This feature was added in csvkit 1.0.2, which is not available from the official package sources for releases older than Bionic. If you’re running Xenial you need to either

• compile the program from source or

• install it via pip with

  sudo pip install csvkit
  

to get the latest version.

in2csv is the simpler option, but I'll leave this in case somebody might find it useful. There's a nice command called xlhtml for converting XLS files to HTML or XML. And once you have the XML, various XML processing tools can be used to do a wide variety of queries on it. In this case:

$ xlhtml -xml ~/foo.xls | xmlstarlet sel -t -m '//pagetitle' -v . -n
Sheet1
Sheet2

The XML that xlhtml generates is like so:

<?xml version="1.0" encoding="iso-8859-1" ?>
<excel_workbook>
    <sheets>
        <sheet>
            <page>0</page>
            <pagetitle>Sheet1</pagetitle>
            <firstrow>0</firstrow>
            <lastrow>11</lastrow>
            <firstcol>0</firstcol>
            <lastcol>0</lastcol>

So, for the sheet names, we can query the pagetitle nodes, for which I used xmlstarlet.