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Edit File: read_lines.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>R: Read/write lines to/from a file</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <link rel="stylesheet" type="text/css" href="R.css" /> </head><body> <table width="100%" summary="page for read_lines {readr}"><tr><td>read_lines {readr}</td><td style="text-align: right;">R Documentation</td></tr></table> <h2>Read/write lines to/from a file</h2> <h3>Description</h3> <p><code>read_lines()</code> reads up to <code>n_max</code> lines from a file. New lines are not included in the output. <code>read_lines_raw()</code> produces a list of raw vectors, and is useful for handling data with unknown encoding. <code>write_lines()</code> takes a character vector or list of raw vectors, appending a new line after each entry. </p> <h3>Usage</h3> <pre> read_lines(file, skip = 0, skip_empty_rows = FALSE, n_max = -1L, locale = default_locale(), na = character(), progress = show_progress()) read_lines_raw(file, skip = 0, n_max = -1L, progress = show_progress()) write_lines(x, path, sep = "\n", na = "NA", append = FALSE) </pre> <h3>Arguments</h3> <table summary="R argblock"> <tr valign="top"><td><code>file</code></td> <td> <p>Either a path to a file, a connection, or literal data (either a single string or a raw vector). </p> <p>Files ending in <code>.gz</code>, <code>.bz2</code>, <code>.xz</code>, or <code>.zip</code> will be automatically uncompressed. Files starting with <code>http://</code>, <code>https://</code>, <code>ftp://</code>, or <code>ftps://</code> will be automatically downloaded. Remote gz files can also be automatically downloaded and decompressed. </p> <p>Literal data is most useful for examples and tests. It must contain at least one new line to be recognised as data (instead of a path) or be a vector of greater than length 1. </p> <p>Using a value of <code><a href="clipboard.html">clipboard()</a></code> will read from the system clipboard.</p> </td></tr> <tr valign="top"><td><code>skip</code></td> <td> <p>Number of lines to skip before reading data.</p> </td></tr> <tr valign="top"><td><code>skip_empty_rows</code></td> <td> <p>Should blank rows be ignored altogether? i.e. If this option is <code>TRUE</code> then blank rows will not be represented at all. If it is <code>FALSE</code> then they will be represented by <code>NA</code> values in all the columns.</p> </td></tr> <tr valign="top"><td><code>n_max</code></td> <td> <p>Number of lines to read. If <code>n_max</code> is -1, all lines in file will be read.</p> </td></tr> <tr valign="top"><td><code>locale</code></td> <td> <p>The locale controls defaults that vary from place to place. The default locale is US-centric (like R), but you can use <code><a href="locale.html">locale()</a></code> to create your own locale that controls things like the default time zone, encoding, decimal mark, big mark, and day/month names.</p> </td></tr> <tr valign="top"><td><code>na</code></td> <td> <p>Character vector of strings to interpret as missing values. Set this option to <code>character()</code> to indicate no missing values.</p> </td></tr> <tr valign="top"><td><code>progress</code></td> <td> <p>Display a progress bar? By default it will only display in an interactive session and not while knitting a document. The display is updated every 50,000 values and will only display if estimated reading time is 5 seconds or more. The automatic progress bar can be disabled by setting option <code>readr.show_progress</code> to <code>FALSE</code>.</p> </td></tr> <tr valign="top"><td><code>x</code></td> <td> <p>A data frame to write to disk</p> </td></tr> <tr valign="top"><td><code>path</code></td> <td> <p>Path or connection to write to.</p> </td></tr> <tr valign="top"><td><code>sep</code></td> <td> <p>The line separator. Defaults to <code>\n</code>, commonly used on POSIX systems like macOS and linux. For native windows (CRLF) separators use <code>\r\n</code>.</p> </td></tr> <tr valign="top"><td><code>append</code></td> <td> <p>If <code>FALSE</code>, will overwrite existing file. If <code>TRUE</code>, will append to existing file. In both cases, if file does not exist a new file is created.</p> </td></tr> </table> <h3>Value</h3> <p><code>read_lines()</code>: A character vector with one element for each line. <code>read_lines_raw()</code>: A list containing a raw vector for each line. </p> <p><code>write_lines()</code> returns <code>x</code>, invisibly. </p> <h3>Examples</h3> <pre> read_lines(file.path(R.home("doc"), "AUTHORS"), n_max = 10) read_lines_raw(file.path(R.home("doc"), "AUTHORS"), n_max = 10) tmp <- tempfile() write_lines(rownames(mtcars), tmp) read_lines(tmp) read_file(tmp) # note trailing \n write_lines(airquality$Ozone, tmp, na = "-1") read_lines(tmp) </pre> <hr /><div style="text-align: center;">[Package <em>readr</em> version 1.3.1 <a href="00Index.html">Index</a>]</div> </body></html>