522 lines
13 KiB
HTML
522 lines
13 KiB
HTML
<!DOCTYPE html>
|
||
|
||
<html>
|
||
|
||
<head>
|
||
|
||
<meta charset="utf-8" />
|
||
<meta name="generator" content="pandoc" />
|
||
<meta http-equiv="X-UA-Compatible" content="IE=EDGE" />
|
||
|
||
<meta name="viewport" content="width=device-width, initial-scale=1" />
|
||
|
||
|
||
|
||
<title>Comparison of fs functions, base R, and shell commands</title>
|
||
|
||
<script>// Pandoc 2.9 adds attributes on both header and div. We remove the former (to
|
||
// be compatible with the behavior of Pandoc < 2.8).
|
||
document.addEventListener('DOMContentLoaded', function(e) {
|
||
var hs = document.querySelectorAll("div.section[class*='level'] > :first-child");
|
||
var i, h, a;
|
||
for (i = 0; i < hs.length; i++) {
|
||
h = hs[i];
|
||
if (!/^h[1-6]$/i.test(h.tagName)) continue; // it should be a header h1-h6
|
||
a = h.attributes;
|
||
while (a.length > 0) h.removeAttribute(a[0].name);
|
||
}
|
||
});
|
||
</script>
|
||
|
||
<style type="text/css">
|
||
code{white-space: pre-wrap;}
|
||
span.smallcaps{font-variant: small-caps;}
|
||
span.underline{text-decoration: underline;}
|
||
div.column{display: inline-block; vertical-align: top; width: 50%;}
|
||
div.hanging-indent{margin-left: 1.5em; text-indent: -1.5em;}
|
||
ul.task-list{list-style: none;}
|
||
</style>
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
<style type="text/css">body {
|
||
background-color: #fff;
|
||
margin: 1em auto;
|
||
max-width: 700px;
|
||
overflow: visible;
|
||
padding-left: 2em;
|
||
padding-right: 2em;
|
||
font-family: "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
|
||
font-size: 14px;
|
||
line-height: 1.35;
|
||
}
|
||
#TOC {
|
||
clear: both;
|
||
margin: 0 0 10px 10px;
|
||
padding: 4px;
|
||
width: 400px;
|
||
border: 1px solid #CCCCCC;
|
||
border-radius: 5px;
|
||
background-color: #f6f6f6;
|
||
font-size: 13px;
|
||
line-height: 1.3;
|
||
}
|
||
#TOC .toctitle {
|
||
font-weight: bold;
|
||
font-size: 15px;
|
||
margin-left: 5px;
|
||
}
|
||
#TOC ul {
|
||
padding-left: 40px;
|
||
margin-left: -1.5em;
|
||
margin-top: 5px;
|
||
margin-bottom: 5px;
|
||
}
|
||
#TOC ul ul {
|
||
margin-left: -2em;
|
||
}
|
||
#TOC li {
|
||
line-height: 16px;
|
||
}
|
||
table {
|
||
margin: 1em auto;
|
||
border-width: 1px;
|
||
border-color: #DDDDDD;
|
||
border-style: outset;
|
||
border-collapse: collapse;
|
||
}
|
||
table th {
|
||
border-width: 2px;
|
||
padding: 5px;
|
||
border-style: inset;
|
||
}
|
||
table td {
|
||
border-width: 1px;
|
||
border-style: inset;
|
||
line-height: 18px;
|
||
padding: 5px 5px;
|
||
}
|
||
table, table th, table td {
|
||
border-left-style: none;
|
||
border-right-style: none;
|
||
}
|
||
table thead, table tr.even {
|
||
background-color: #f7f7f7;
|
||
}
|
||
p {
|
||
margin: 0.5em 0;
|
||
}
|
||
blockquote {
|
||
background-color: #f6f6f6;
|
||
padding: 0.25em 0.75em;
|
||
}
|
||
hr {
|
||
border-style: solid;
|
||
border: none;
|
||
border-top: 1px solid #777;
|
||
margin: 28px 0;
|
||
}
|
||
dl {
|
||
margin-left: 0;
|
||
}
|
||
dl dd {
|
||
margin-bottom: 13px;
|
||
margin-left: 13px;
|
||
}
|
||
dl dt {
|
||
font-weight: bold;
|
||
}
|
||
ul {
|
||
margin-top: 0;
|
||
}
|
||
ul li {
|
||
list-style: circle outside;
|
||
}
|
||
ul ul {
|
||
margin-bottom: 0;
|
||
}
|
||
pre, code {
|
||
background-color: #f7f7f7;
|
||
border-radius: 3px;
|
||
color: #333;
|
||
white-space: pre-wrap;
|
||
}
|
||
pre {
|
||
border-radius: 3px;
|
||
margin: 5px 0px 10px 0px;
|
||
padding: 10px;
|
||
}
|
||
pre:not([class]) {
|
||
background-color: #f7f7f7;
|
||
}
|
||
code {
|
||
font-family: Consolas, Monaco, 'Courier New', monospace;
|
||
font-size: 85%;
|
||
}
|
||
p > code, li > code {
|
||
padding: 2px 0px;
|
||
}
|
||
div.figure {
|
||
text-align: center;
|
||
}
|
||
img {
|
||
background-color: #FFFFFF;
|
||
padding: 2px;
|
||
border: 1px solid #DDDDDD;
|
||
border-radius: 3px;
|
||
border: 1px solid #CCCCCC;
|
||
margin: 0 5px;
|
||
}
|
||
h1 {
|
||
margin-top: 0;
|
||
font-size: 35px;
|
||
line-height: 40px;
|
||
}
|
||
h2 {
|
||
border-bottom: 4px solid #f7f7f7;
|
||
padding-top: 10px;
|
||
padding-bottom: 2px;
|
||
font-size: 145%;
|
||
}
|
||
h3 {
|
||
border-bottom: 2px solid #f7f7f7;
|
||
padding-top: 10px;
|
||
font-size: 120%;
|
||
}
|
||
h4 {
|
||
border-bottom: 1px solid #f7f7f7;
|
||
margin-left: 8px;
|
||
font-size: 105%;
|
||
}
|
||
h5, h6 {
|
||
border-bottom: 1px solid #ccc;
|
||
font-size: 105%;
|
||
}
|
||
a {
|
||
color: #0033dd;
|
||
text-decoration: none;
|
||
}
|
||
a:hover {
|
||
color: #6666ff; }
|
||
a:visited {
|
||
color: #800080; }
|
||
a:visited:hover {
|
||
color: #BB00BB; }
|
||
a[href^="http:"] {
|
||
text-decoration: underline; }
|
||
a[href^="https:"] {
|
||
text-decoration: underline; }
|
||
|
||
code > span.kw { color: #555; font-weight: bold; }
|
||
code > span.dt { color: #902000; }
|
||
code > span.dv { color: #40a070; }
|
||
code > span.bn { color: #d14; }
|
||
code > span.fl { color: #d14; }
|
||
code > span.ch { color: #d14; }
|
||
code > span.st { color: #d14; }
|
||
code > span.co { color: #888888; font-style: italic; }
|
||
code > span.ot { color: #007020; }
|
||
code > span.al { color: #ff0000; font-weight: bold; }
|
||
code > span.fu { color: #900; font-weight: bold; }
|
||
code > span.er { color: #a61717; background-color: #e3d2d2; }
|
||
</style>
|
||
|
||
|
||
|
||
|
||
</head>
|
||
|
||
<body>
|
||
|
||
|
||
|
||
|
||
<h1 class="title toc-ignore">Comparison of fs functions, base R, and
|
||
shell commands</h1>
|
||
|
||
|
||
|
||
<p>Most of the functionality is <strong>fs</strong> can be approximated
|
||
with functions in <strong>base R</strong> or in a command line shell.
|
||
The table at the end of this vignette can be used as a translation aid
|
||
between these three methods.</p>
|
||
<p><strong>fs</strong> functions smooth over some of the idiosyncrasies
|
||
of file handling with base R functions:</p>
|
||
<ul>
|
||
<li><p>Vectorization. All <strong>fs</strong> functions are vectorized,
|
||
accepting multiple paths as input. Base functions are inconsistently
|
||
vectorized.</p></li>
|
||
<li><p>Predictable return values that always convey a path. All
|
||
<strong>fs</strong> functions return a character vector of paths, a
|
||
named integer or a logical vector, where the names give the paths. Base
|
||
return values are more varied: they are often logical or contain error
|
||
codes which require downstream processing.</p></li>
|
||
<li><p>Explicit failure. If <strong>fs</strong> operations fail, they
|
||
throw an error. Base functions tend to generate a warning and a system
|
||
dependent error code. This makes it easy to miss a failure.</p></li>
|
||
<li><p>UTF-8 all the things. <strong>fs</strong> functions always
|
||
convert input paths to UTF-8 and return results as UTF-8. This gives you
|
||
path encoding consistency across OSes. Base functions rely on the native
|
||
system encoding.</p></li>
|
||
<li><p>Naming convention. <strong>fs</strong> functions use a consistent
|
||
naming convention. Because base R’s functions were gradually added over
|
||
time there are a number of different conventions used
|
||
(e.g. <code>path.expand()</code> vs <code>normalizePath()</code>;
|
||
<code>Sys.chmod()</code> vs <code>file.access()</code>).</p></li>
|
||
</ul>
|
||
<div id="directory-functions" class="section level2">
|
||
<h2>Directory functions</h2>
|
||
<table>
|
||
<colgroup>
|
||
<col width="33%" />
|
||
<col width="33%" />
|
||
<col width="33%" />
|
||
</colgroup>
|
||
<thead>
|
||
<tr class="header">
|
||
<th>fs</th>
|
||
<th>base</th>
|
||
<th>shell</th>
|
||
</tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr class="odd">
|
||
<td><code>dir_ls("path")</code></td>
|
||
<td><code>list.files("path")</code></td>
|
||
<td><code>ls path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>dir_info("path")</code></td>
|
||
<td><code>do.call(rbind, lapply(list.files("path"), file.info))</code></td>
|
||
<td><code>ls -al path</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>dir_copy("path", "new-path")</code></td>
|
||
<td><code>dir.create("new-path"); file.copy("path", "new-path", recursive=TRUE)</code></td>
|
||
<td><code>cp path new-path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>dir_create("path")</code></td>
|
||
<td><code>dir.create("path")</code></td>
|
||
<td><code>mkdir path</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>dir_delete("path")</code></td>
|
||
<td><code>unlink("path", recursive = TRUE)</code></td>
|
||
<td><code>rm -rf path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>dir_exists("path")</code></td>
|
||
<td><code>dir.exists("path")</code></td>
|
||
<td><code>if [ -d "path" ]; then ... ; fi</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><del><code>dir_move()</code></del> (see <code>file_move</code>)</td>
|
||
<td><code>file.rename("path", "new-path")</code></td>
|
||
<td><code>mv path new-path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>dir_map("path", fun)</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><code>for file in $(ls path); do ...; done</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>dir_tree("path")</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><code>tree path</code></td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
</div>
|
||
<div id="file-functions" class="section level2">
|
||
<h2>File functions</h2>
|
||
<table>
|
||
<colgroup>
|
||
<col width="33%" />
|
||
<col width="33%" />
|
||
<col width="33%" />
|
||
</colgroup>
|
||
<thead>
|
||
<tr class="header">
|
||
<th>fs</th>
|
||
<th>base</th>
|
||
<th>shell</th>
|
||
</tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr class="odd">
|
||
<td><code>file_chmod("path", "mode")</code></td>
|
||
<td><code>Sys.chmod("path", "mode")</code></td>
|
||
<td><code>chmod mode path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>file_chown("path", "user_id", "group_id")</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><code>chown options path</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>file_copy("path", "new-path")</code></td>
|
||
<td><code>file.copy("path", "new-path")</code></td>
|
||
<td><code>cp path new-path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>file_create("new-path")</code></td>
|
||
<td><code>file.create("new-path")</code></td>
|
||
<td><code>touch new-path</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>file_delete("path")</code></td>
|
||
<td><code>unlink("path")</code></td>
|
||
<td><code>rm path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>file_exists("path")</code></td>
|
||
<td><code>file.exists("path")</code></td>
|
||
<td><code>if [ -f "path" ]; then ... ; fi</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>file_info("path")</code></td>
|
||
<td><code>file.info("path")</code></td>
|
||
<td><code>ls -al path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>file_move("path", "new-path")</code></td>
|
||
<td><code>file.rename("path", "new-path")</code></td>
|
||
<td><code>mv path new-path</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>file_show("path")</code></td>
|
||
<td><code>browseURL("path")</code></td>
|
||
<td><code>open path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>file_touch()</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><code>touch path</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>file_temp()</code></td>
|
||
<td><code>tempfile()</code></td>
|
||
<td><code>mktemp</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>file_test()</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><code>if [ -d "path" ]; then ...; fi</code></td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
</div>
|
||
<div id="path-functions" class="section level2">
|
||
<h2>Path functions</h2>
|
||
<table>
|
||
<colgroup>
|
||
<col width="33%" />
|
||
<col width="33%" />
|
||
<col width="33%" />
|
||
</colgroup>
|
||
<thead>
|
||
<tr class="header">
|
||
<th>fs</th>
|
||
<th>base</th>
|
||
<th>shell</th>
|
||
</tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr class="odd">
|
||
<td><code>path("top_dir", "nested_dir", "file", ext = "ext")</code></td>
|
||
<td><code>file.path("top_dir", "nested_dir", "file.ext")</code></td>
|
||
<td><code>top_dir/nested_dir/file.ext</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>path_temp()</code>, <code>path_temp("path")</code></td>
|
||
<td><code>tempdir()</code>,
|
||
<code>file.path(tempdir(), "path")</code></td>
|
||
<td><code>mktemp -d</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>path_expand("~/path")</code></td>
|
||
<td><code>path.expand()</code></td>
|
||
<td><code>realpath -m -s ~/path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>path_dir("path")</code></td>
|
||
<td><code>dirname("path")</code></td>
|
||
<td><code>dirname path</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>path_file("path")</code></td>
|
||
<td><code>basename("path")</code></td>
|
||
<td><code>basename path</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>path_home()</code></td>
|
||
<td><code>path.expand("~")</code></td>
|
||
<td><code>$HOME</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>path_package("pkgname", "dir", "file")</code></td>
|
||
<td><code>system.file("dir", "file", package = "pkgname")</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>path_norm("path")</code></td>
|
||
<td><code>normalizePath()</code></td>
|
||
<td><code>realpath</code></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>path_real("path")</code></td>
|
||
<td><code>normalizePath(mustWork = TRUE)</code></td>
|
||
<td><code>realpath</code></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>path_rel("path/foo", "path/bar")</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>path_common(c("path/foo", "path/bar", "path/baz"))</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>path_ext_remove("path")</code></td>
|
||
<td><code>sub("\\.[a-zA-Z0-9]*$", "", "path")</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
</tr>
|
||
<tr class="odd">
|
||
<td><code>path_ext_set("path", "new_ext")</code></td>
|
||
<td><code>sub("\\.[a-zA-Z0-9]*$", "new_ext", "path")</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
</tr>
|
||
<tr class="even">
|
||
<td><code>path_sanitize("path")</code></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
<td><em>No direct equivalent</em></td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
</div>
|
||
|
||
|
||
|
||
<!-- code folding -->
|
||
|
||
|
||
<!-- dynamically load mathjax for compatibility with self-contained -->
|
||
<script>
|
||
(function () {
|
||
var script = document.createElement("script");
|
||
script.type = "text/javascript";
|
||
script.src = "https://mathjax.rstudio.com/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML";
|
||
document.getElementsByTagName("head")[0].appendChild(script);
|
||
})();
|
||
</script>
|
||
|
||
</body>
|
||
</html>
|