I've been trying to use xmstarlet in R instead of running my xmlstarlet script in bash and then pipe it to R, but everything I've tried hasn't worked. I am not even sure if it is possible.
I've tried this:
shell(cmd=(xmlstarlet sel -t -c "someinput"), intern=TRUE)
The command alone in bash works, but when I try to do this, I get this error:
Error: unexpected symbol in "shell(cmd=(xmlstarlet sel"
I an not really sure if I should be using system() instead of shell. I've also used system, but without success
EDIT:
Full command example, can also be found here with full xml file
xmlstarlet sel -t -m "/bookstore/book/Description" -i "@stock='YES'" -v '/bookstore/book/Location/shelf'
Save your command as a character vector and use system:
cmd <- "xml el http://stackoverflow.com"
system(command = cmd, intern = T)
This gives me
http://stackoverflow.com:12.163: EntityRef: expecting ';'
/cdn.sstatic.net/Sites/stackoverflow/img/apple-touch-icon@2.png?v=73d79a89bded&a
^
[1] "html" "html/head" "html/head/title"
[4] "html/head/link" "html/head/link/link" "html/head/link/link/link"
[7] "html/head/link/link/link/meta"
attr(,"status")
[1] 4
If you are using double quotes inside the xmlstarlet command you have to escape them with a backslash. Using the example you added to the question:
cmd <- "xmlstarlet sel -t -m \"bookstore/book\" -i \"Description/stock='YES'\" -v \"Location/shelf\" -n /PATH/TO/books.xml"
system(command = cmd, intern=T)
Output:
[1] "30" "21" "11"