blob: a8424cd9a79c4f27de74e1973f0462afddac1675 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta http-equiv="Content-Language" content="en" />
<title>s6-portable-utils: the s6-test program</title>
<meta name="Description" content="s6-portable-utils: the s6-test program" />
<meta name="Keywords" content="s6-portable-utils command s6-test test" />
<!-- <link rel="stylesheet" type="text/css" href="//skarnet.org/default.css" /> -->
</head>
<body>
<p>
<a href="index.html">s6-portable-utils</a><br />
<a href="//skarnet.org/software/">Software</a><br />
<a href="//skarnet.org/">skarnet.org</a>
</p>
<h1> The <tt>s6-test</tt> program </h1>
<p>
s6-test evaluates an expression and indicates the result via its
exit status.
</p>
<h2> Interface </h2>
<pre>
s6-test <em>expression...</em>
</pre>
<p>
s6-test acts as the generic
<a href="https://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html">test</a> utility,
but it diverges from the specification on one point: if an argument starts with a backslash,
this backslash is ignored (and the argument cannot be an operation). This is a simple
disambiguation technique that has unfortunately not been chosen by the standard.
</p>
<p>
s6-test accepts an arbitrary number of arguments.
</p>
<h2> Exit codes </h2>
<ul>
<li> 0: the test is true </li>
<li> 1: the test is false </li>
<li> 100: wrong usage </li>
<li> 101: internal error (should never happen, warrants a bug-report) </li>
<li> 111: system call failure </li>
</ul>
<h2> Posixness </h2>
<p>
s6-test <strong>is not</strong> suitable as a Single Unix
<a href="https://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html">test</a>
program; however, if your arguments never start with a backslash, it exhibits the
exact same behaviour.
</p>
<h2> Non-standard expressions </h2>
<ul>
<li> <tt>-v <em>VAR</em></tt> : tests whether the
<em>VAR</em> variable is defined in the current environment. </li>
<li> <tt><em>string</em> =~ <em>pattern</em></tt> :
tries to match <em>string</em> against extended regular expression
<em>pattern</em>. True if any part of <em>string</em> matches <em>pattern</em>;
in order to match whole strings, you must anchor <em>pattern</em> with
<tt>^</tt> and <tt>$</tt> markers. </li>
</ul>
</body>
</html>
|
