xmlstarlet:tldr:7d134

The command you mentioned consists of two parts, separated by the pipe symbol |.

1. ${cat filename-xml}: This part is using the cat command to read the contents of a file specified by filename-xml. The ${...} syntax is often used in shell scripting or command substitution to refer to the value of a variable. In this case, filename-xml is expected to be a variable holding the actual filename. The output of cat filename-xml is then passed to the next part of the command through the pipe.

2. xmlstarlet format: This part runs the xmlstarlet command with the action format. xmlstarlet is a command-line tool used for querying, editing, and formatting XML files. The format action is used to reformat the XML input according to a specific style or indentation. In this case, the input received from the previous command (cat filename-xml) will be reformatted by xmlstarlet using the default formatting settings.

In summary, the command takes the contents of a file specified by a variable named filename-xml, displays the original XML content using the cat command, and then passes it to xmlstarlet to reformat the XML output.