getwd()
setwd(r"(C:\Users\BMChun\Desktop\2020b\기초프로그래밍\workingdir\8._read_and_write_data)")

tt <- read.table(file = "./txt/text data4.txt",skip = 1 ,header = T)

csv <- read.csv(file = "./csv/csv_data2.csv")
csv

as.data.frame(read_xlsx(path="xlsx/xlsx_data.xlsx", sheet=2))

install.packages("haven")
require(haven)
as.data.frame(read_sas(data_file = "sas/sas_data.sas7bdat"))

url = "http://www.stats.ox.ac.uk/pub/datasets/csb/ch11b.dat"
url_data = read.table(url)
url_data

url = "https://sakai.unc.edu/access/content/group/3d1eb92e-7848-4f55-90c3-7c72a54e7e43/public/data/bycatch.csv"
url_data = read.csv(url)
url_data

require("XML")
require("httr")
url = "https://en.wikipedia.org/wiki/List_of_countries_and_dependencies_by_population"
r = GET(url)
cont <- content(r, "text")
ht <- readHTMLTable(doc =cont,header = T)
ht

load(file="Rdata/rdata.RData")
rdata_data

require(data.table)
fread("txt/text data1.txt")

write.csv(csv, file = "csv/writed.csv")

fl = list.files(path = "temp/")
file <- read.csv(paste("temp/",fl[1],sep=''))
for (i in 2:length(fl)) {
  file <- rbind(file,read.csv(paste("temp/",fl[i],sep = '')))
}
file

file[order(file$sepal.length),]