Implement comment.char argument in fread

[arunsrinivasan]

Similar to read.table.

[mattdowle]

Need to ignore whole lines (starting with comment) as well as trailing comments after valid lines.

[mattdowle]

Then update this question : http://stackoverflow.com/questions/18920777/fread-data-table-in-r/

[eddelbuettel]

Bump. Needing this right now.

[RLathamBAH]

+1

[DavidArenburg]

Actually fread seem to assume it already has this implemented as it is mentioning comment.char in its warnings. This is a warning I've recently saw (using the dev 1.10.5 version)

Warning in fread(file_x, skip = startind - 1L, header = TRUE, fill = TRUE) :
Stopped early on line 2. Expected 168 fields but found 235. Consider fill=TRUE and comment.char=.

Also, not sure why isn't this an error? It make it harder to catch it with tryCatch

[eddelbuettel]

Interesting. Can you chase the comment and find an author and commit per git blame?
I am mostly using the CRAN version so I work around the issue (when I have to, which is not that often).

[DavidArenburg]

@eddelbuettel You can find it here https://github.com/Rdatatable/data.table/blame/master/src/fread.c#L2351