You need to recursively walk the parse tree/AST. See, e.g., https://adv-r.hadley.nz/expressions.html#ast-funs
Hadley On Wed, Jun 20, 2018 at 10:08 AM, Sigbert Klinke <sigb...@wiwi.hu-berlin.de> wrote: > Hi, > > I have read an R program with > > expr <- parse("myRprg.R") > > How can I extract the parameters of a specifc R command, e.g. "library"? > > So, if myprg.R containes the lines > > library("xyz") > library("abc") > > then I would like to get "xyz" and "abc" back from expr. > > Thanks in advance > > Sigbert > > -- > https://hu.berlin/sk > > > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- http://hadley.nz ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.