R: Read text lines from a file

readLines {brio} | R Documentation

## Read text lines from a file

### Description

This is a drop in replacement for `base::readLines()` with restricted functionality. Compared to `base::readLines()` it:

- Only works with file paths, not connections.

- Assumes the files are always UTF-8 encoded.

- Does not warn or skip embedded nulls, they will likely crash R.

- Does not warn if the file is missing the end of line character.

- The arguments `ok`, `warn`, `encoding` and `skipNul` are ignored, with a warning.

### Usage

    readLines(con, n = -1, ok, warn, encoding, skipNul)

### Arguments

`con` | A character string of the path to a file. Throws an error if a connection object is passed.
`n` | integer. The number of lines to read. A negative number means read all the lines in the file.
`ok` | Ignored, with a warning.
`warn` | Ignored, with a warning.
`encoding` | Ignored, with a warning.
`skipNul` | Ignored, with a warning.

### Value

A UTF-8 encoded character vector of the lines in the file.

### See Also

`writeLines()`

### Examples

    authors_file <- file.path(R.home("doc"), "AUTHORS")
    data <- readLines(authors_file)

    # Trying to use connections throws an error
    con <- file(authors_file)
    try(readLines(con))
    close(con)

    # Trying to use unsupported args throws a warning
    data <- readLines(authors_file, encoding = "UTF-16")

[Package brio version 1.1.2 Index]