summaryrefslogtreecommitdiff
path: root/static/plan9-4e/man1/test.1
blob: 7de80217a9b888c3f5c39dfffc1a6fb7f1db44a5 (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
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
.TH TEST 1
.SH NAME
test \- set status according to condition
.SH SYNOPSIS
.B test
.I expr
.SH DESCRIPTION
.I Test
evaluates the expression
.IR expr .
If the value is true the exit status is null; otherwise the
exit status is non-null.
If there are no arguments the exit status is non-null.
.PP
The following primitives are used to construct
.IR expr .
.TP "\w'\fIn1 \fL-eq \fIn2\fLXX'u"
.BI -r " file"
True if the file exists (is accessible) and is readable.
.PD0
.TP
.BI -w " file"
True if the file exists and is writable.
.TP
.BI -x " file"
True if the file exists and has execute permission.
.TP
.BI -e " file
True if the file exists.
.TP
.BI -f " file"
True if the file exists and is a plain file.
.TP
.BI -d " file"
True if the file exists and is a directory.
.TP
.BI -s " file"
True if the file exists and has a size greater than zero.
.TP
.BI -t " fildes
True if the open file whose file descriptor number is
.I fildes
(1 by default)
is the same file as
.BR /dev/cons .
.TP
.BI -A " file"
True if the file exists and is append-only.
.TP
.BI -L " file"
True if the file exists and is exclusive-use.
.TP
.IB s1 " = " s2
True
if the strings
.I s1
and
.I s2
are identical.
.TP
.IB s1 " != " s2
True
if the strings
.I s1
and
.I s2
are not identical.
.TP
s1
True if
.I s1
is not the null string.
(Deprecated.)
.TP
.BI -n " s1"
True if the length of string
.I s1
is non-zero.
.TP
.BI -z " s1"
True if the length of string
.I s1
is zero.
.TP
.IB n1 " -eq " n2
True if the integers
.I n1
and
.I n2
are arithmetically equal.
Any of the comparisons
.BR -ne ,
.BR -gt ,
.BR -ge ,
.BR -lt ,
or
.BR -le
may be used in place of
.BR -eq .
The (nonstandard) construct
.BI -l " string\f1,
meaning the length of
.IR string ,
may be used in place of an integer.
.PD
.PP
These primaries may be combined with the
following operators:
.TP "\w'\fL( \fIexpr\fL )XX'u"
.B  !
unary negation operator
.PD0
.TP
.B  -o
binary
.I or
operator
.TP
.B  -a
binary
.I and
operator; higher precedence than
.BR -o
.TP
.BI "( " expr " )"
parentheses for grouping.
.PD
.PP
The primitives
.BR -b ,
.BR -u ,
.BR -g ,
and
.BR -s
return false; they are recognized for compatibility with POSIX.
.PP
Notice that all the operators and flags are separate
arguments to
.IR test .
Notice also that parentheses and equal signs are meaningful
to
.I rc
and must be enclosed in quotes.
.SH EXAMPLES
.I Test
is a dubious way to check for specific character strings:
it uses a process to do what an
.IR rc (1)
match or switch statement can do.
The first example is not only inefficient but wrong, because
.I test
understands the purported string
.B  \&"-c"
as an option.
.IP
.EX
if (test $1 '=' "-c") echo OK	# wrong!
.EE
.LP
A better way is
.IP
.EX
if (~ $1 -c) echo OK
.EE
.PP
Test whether 
.L abc
is in the current directory.
.IP
.B test -f abc -o -d abc
.SH SOURCE
.B /sys/src/cmd/test.c
.SH "SEE ALSO"
.IR rc (1)