test.1

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)test.1	8.1	9/11/90
.TH test 1 
.SH Name
test \- test conditional expression
.SH Syntax
.B test
.I expr
.br
[
.I expr
]
.SH Description
.NXR "test command"
.NXA "test command" "find command"
The
.PN test
command evaluates the expression
.IR expr .
If the value of
.IR expr
is true, the
.PN test
command returns a zero exit status; otherwise, it
returns a nonzero exit status.  The
.PN test
command also returns a nonzero exit status if no arguments are specified.
.SH Options
The following primitives are used to construct
.IR expr :
.TP 20
\fB\-\|r\fI file\fR
Tests if the file exists and is readable.
.TP 20
\fB\-\|w\fI file\fR
Tests if the file exists and is writable.
.TP 20 
\fB\-\|f\fI file\fR
Tests if the file exists and is not a directory.
.TP 20 
\fB\-\|d\fI file\fR
Tests if the file exists and is a directory.
.TP 20 
\fB\-\|s\fI file\fR
Tests if the file exists and has a size greater than zero.
.TP 20 
\fB\-t\fR [\fI fildes\fR ]
Tests if the open file, whose file descriptor number is 
.I fildes 
(1 by default), is associated with a terminal device.
.TP 20 
\fB\-\|z\fI s1\fR
Tests if the length of string
.I s1
is zero.
.TP 20 
\fB\-\|n\fI s1\fR 
Tests if the length of the string
.I s1
is nonzero.
.TP 20 
\fIs1 = s2\fR
Tests
if the strings
.I s1
and
.I s2
are equal.
.TP 20
\fIs1 != s2\fR
Tests
if the strings
.I s1
and
.I s2
are not equal.
.TP
\fIs1\fR
Tests if
.I s1
is not the null string.
.TP 20
\fRn1 \fB\-eq\fR n2
Tests if number1 equals number2.  
.TP 20
\fRn1 \fB\-ge\fR n2
Tests if number1 is greater than or equal to number2.  
.TP 20
\fRn1 \fB\-gt\fR n2
Tests if number1 is greater than number2.  
.TP 20
\fRn1 \fB\-le\fR n2
Tests if number1 is less than or equal to number2.
.TP 20
\fRn1 \fB\-lt\fR n2
Tests if number1 is less than number2. 
.TP 20
\fRn1 \fB\-ne\fR n2
Tests if number1 is not equal to number2.   
.PP
These primitives can be combined with the
following operators:
.TP 20
\fR!expr
Negates evaluation of expression.  
.TP 20
\fRexpr \fB\-a\fR expr
Tests logical
.I and
of two expressions.  
.TP 20
\fRexpr \fB\-o\fR expr
Tests logical
.I or
of two expressions.  
.TP 20 
\fR( expr... )
Groups expressions.  
.PP
The
.B \-a
operator takes precedence over the
.B \-o
operator.  Note that all the operators and flags are separate
arguments to
.PN test .
Note also that parentheses are meaningful
to the Shell and must be escaped.
.SH See Also
find(1), sh(1), test(1sh5)