UUIDs to Patient Barcodes

gistfile1.r

library(RCurl)
library(rjson)

# Read sample UUIDs.
uuids <- read.csv(file="~/uuids.csv")

# Convert to character vector.
uuids <- as.vector(t(uuids))

# Query TCGA's UUID to barcode Web Service.
resp <- getURL("https://tcga-data.nci.nih.gov/uuid/uuidws/mapping/json/uuid/batch", customrequest="POST", httpheader=c("Content-Type: text/plain"), postfields=paste(uuids, collapse=","))

# Extract mappings from response.
mappings <- fromJSON(resp)$uuidMapping

# Extract patient barcode from sample barcode.
mappings <- lapply(mappings, function (mapping) {
    mapping$barcode <- substr(mapping$barcode, 0, 12)
    return(mapping)
})

I'm getting error while extracting mappings:
Error in fromJSON(resp) : unexpected character '<'

please help.

I got the same problem, please help ~

same error here: unexpected character '<'