mirror of
https://github.com/fish-shell/fish-shell
synced 2024-12-26 12:53:13 +00:00
109 lines
4.7 KiB
Text
109 lines
4.7 KiB
Text
\section test test - perform tests on files and text
|
|
|
|
\subsection test-synopsis Synopsis
|
|
<tt>test [EXPRESSION]</tt>
|
|
|
|
\subsection test-description Description
|
|
|
|
Tests the expression given and sets the exit status to 0 if true,
|
|
and 1 if false. An expression is made up of one or more operators
|
|
and their arguments.
|
|
|
|
The following operators are available to examine files and directories:
|
|
- <tt>-b FILE</tt> returns true if \c FILE is a block device.
|
|
- <tt>-c FILE</tt> returns true if \c FILE is a character device.
|
|
- <tt>-d FILE</tt> returns true if \c FILE is a directory.
|
|
- <tt>-e FILE</tt> returns true if \c FILE exists.
|
|
- <tt>-f FILE</tt> returns true if \c FILE is a regular file.
|
|
- <tt>-g FILE</tt> returns true if \c FILE has the set-group-ID bit set.
|
|
- <tt>-G FILE</tt> returns true if \c FILE exists and has the same group ID
|
|
as the current user.
|
|
- <tt>-L FILE</tt> returns true if \c FILE is a symbolic link.
|
|
- <tt>-O FILE</tt> returns true if \c FILE exists and is owned by the current
|
|
user.
|
|
- <tt>-p FILE</tt> returns true if \c FILE is a named pipe.
|
|
- <tt>-r FILE</tt> returns true if \c FILE is marked as readable.
|
|
- <tt>-s FILE</tt> returns true if the size of \c FILE is greater than zero.
|
|
- <tt>-S FILE</tt> returns true if \c FILE is a socket.
|
|
- <tt>-t FD</tt> returns true if the file descriptor \c FD is a terminal (TTY).
|
|
- <tt>-u FILE</tt> returns true if \c FILE has the set-user-ID bit set.
|
|
- <tt>-w FILE</tt> returns true if \c FILE is marked as writable; note that this does not check if the filesystem is read-only.
|
|
- <tt>-x FILE</tt> returns true if \c FILE is marked as executable.
|
|
|
|
The following operators are available to compare and examine text strings:
|
|
- <tt>STRING1 = STRING2</tt> returns true if the strings \c STRING1 and
|
|
\c STRING2 are identical.
|
|
- <tt>STRING1 != STRING2</tt> returns true if the strings \c STRING1 and
|
|
\c STRING2 are not identical.
|
|
- <tt>-n STRING</tt> returns true if the length of \c STRING is non-zero.
|
|
- <tt>-z STRING</tt> returns true if the length of \c STRING is zero.
|
|
|
|
The following operators are available to compare and examine numbers:
|
|
- <tt>NUM1 -eq NUM2</tt> returns true if \c NUM1 and \c NUM2 are numerically equal.
|
|
- <tt>NUM1 -ne NUM2</tt> returns true if \c NUM1 and \c NUM2 are not numerically equal.
|
|
- <tt>NUM1 -gt NUM2</tt> returns true if \c NUM1 is greater than <tt>NUM2</tt>.
|
|
- <tt>NUM1 -ge NUM2</tt> returns true if \c NUM1 is greater than or equal to <tt>NUM2</tt>.
|
|
- <tt>NUM1 -lt NUM2</tt> returns true if \c NUM1 is less than <tt>NUM2</tt>.
|
|
- <tt>NUM1 -le NUM2</tt> returns true if \c NUM1 is less than or equal to <tt>NUM2</tt>.
|
|
|
|
Note that only integers are supported. For more complex mathematical
|
|
operations, including fractions, the \c env program may be useful. Consult the
|
|
documentation for your operating system.
|
|
|
|
Expressions can be combined using the following operators:
|
|
- <tt>COND1 -a COND2</tt> returns true if both \c COND1 and \c COND2 are true.
|
|
- <tt>COND1 -o COND2</tt> returns true if either \c COND1 or \c COND2 are true.
|
|
|
|
Expressions can be inverted using the \c ! operator:
|
|
- <tt>! EXPRESSION</tt> returns true if \c EXPRESSION is false, and false if
|
|
\c EXPRESSION is true.
|
|
|
|
Expressions can be grouped using parentheses.
|
|
- <tt>( EXPRESSION )</tt> returns the value of <tt>EXPRESSION</tt>.
|
|
Note that parentheses will usually require escaping with <tt>\\(</tt> to avoid
|
|
being interpreted as a command substitution.
|
|
|
|
\subsection test-example Examples
|
|
|
|
If the \c /tmp directory exists, copy the \c /etc/motd file to it:
|
|
|
|
<pre>
|
|
if test -d /tmp
|
|
cp /etc/motd /tmp/motd
|
|
end
|
|
</pre>
|
|
|
|
If the variable \c MANPATH is defined and not empty, print the contents.
|
|
(If \c MANPATH is not defined, then it will expand to zero arguments, unless
|
|
quoted.)
|
|
|
|
<pre>
|
|
if test -n "$MANPATH"
|
|
echo $MANPATH
|
|
end
|
|
</pre>
|
|
|
|
Parentheses and the \c -o and \c -a operators can be combined to produce
|
|
more complicated expressions. In this example, success is printed if there is
|
|
a \c /foo or \c /bar file as well as a \c /baz or \c /bat file.
|
|
|
|
<pre>
|
|
if test \\( -f /foo -o -f /bar \\) -a \\( -f /baz -o -f /bat \\)
|
|
echo Success.
|
|
end.
|
|
</pre>
|
|
|
|
\subsection test-standards Standards
|
|
|
|
\c test implements a subset of the
|
|
<a href="http://www.unix.com/man-page/POSIX/1/test/">IEEE Std 1003.1-2008
|
|
(POSIX.1) standard</a>. The following exceptions apply:
|
|
- The \c < and \c > operators for comparing strings are not implemented.
|
|
- Because this test is a shell builtin and not a standalone utility, using
|
|
the -c flag on a special file descriptors like standard input and output
|
|
may not return the same result when invoked from within a pipe as one
|
|
would expect when invoking the \c test utility in another shell.
|
|
|
|
In cases such as this, one can use \c command \c test to explicitly
|
|
use the system's standalone \c test rather than this \c builtin \c test.
|
|
|