```{r setup, include=FALSE} knitr::opts_chunk$set(echo = TRUE)

Basic operations in R:
- Download (zip) files
- Extract compressed files to a folder
- Check & Create a folder or subfolders
- List & Read files in a folder


# Download

```{r}
download.file("https://github.com/tpetric7/tpetric7.github.io/archive/refs/heads/main.zip",
              "d:/Users/teodo/Downloads/tpetric7-master.zip")

Check & create directory

pot <- "d:/Users/teodo/Downloads/tpetric7-master"
exist <- dir.exists(pot)
exist

ifelse(exist == FALSE, 
       dir.create(pot, showWarnings = TRUE, recursive = TRUE), 
       "directory already exists")

Unzip

unzip("d:/Users/teodo/Downloads/tpetric7-master.zip", exdir = pot)

Create subfolders

subfolder_names <- c("a","b","c","d") 
for (i in 1:length(subfolder_names)){
  folder <- dir.create(paste0(pot, "/", subfolder_names[i]))
}

List files

seznam <- list.files(pot, pattern = "\\.txt$", recursive = TRUE, full.names = TRUE)
seznam

Read files

library(tidyverse)
alltxt <- seznam %>% map(read_lines)

head(alltxt[[5]], 12)
cat(head(alltxt[[5]], 12))

Base R:

alltxt <- lapply(seznam, readLines)

head(alltxt[[5]], 12)
cat(head(alltxt[[5]], 12))