ch33_01.htm

编程珍珠,里面很多好用的代码,大家可以参考学习呵呵,

<dt>
<b><tt class="literal">Can't call method "</tt><em class="replaceable">%s</em><tt class="literal">" in empty package "</tt><em class="replaceable">%s</em><tt class="literal">"</tt></b>
</dt>
<dd>
<p>(F) You called a method correctly, and it correctly indicated a package
functioning as a class, but that package doesn't have <em class="emphasis">anything</em> defined
in it, let alone methods.</p>
</dd>


<dt>
<b><tt class="literal">Can't call method "</tt><em class="replaceable">%s</em><tt class="literal">" on unblessed reference</tt></b>
</dt>
<dd>
<p>(F) A method call must know in what package it's supposed to run.  It
ordinarily finds this out from the object reference you supply, but
you didn't supply an object reference in this case.  A reference isn't
an object reference until it has been blessed.</p>
</dd>


<dt>
<b><tt class="literal">Can't call method "</tt><em class="replaceable">%s</em><tt class="literal">" without a package or object reference</tt></b>
</dt>
<dd>
<p>(F) You used the syntax of a method call, but the slot filled by the
object reference or package name contains an expression that returns a
defined value that is neither an object reference nor a package name. Something like this will reproduce the error:
<blockquote>
<pre class="programlisting">$BADREF = 42;
process $BADREF 1,2,3;
$BADREF-&gt;process(1,2,3);</pre>
</blockquote>
</p>
</dd>


<dt>
<b><tt class="literal">Can't call method "</tt><em class="replaceable">%s</em><tt class="literal">" on an undefined value</tt></b>
</dt>
<dd>
<p>(F) You used the syntax of a method call, but the slot filled by the
object reference or package name contains an undefined value.
Something like this will reproduce the error:
<blockquote>
<pre class="programlisting">$BADREF = undef;
process $BADREF 1,2,3;
$BADREF-&gt;process(1,2,3);</pre>
</blockquote>
</p>
</dd>


<dt>
<b><tt class="literal">Can't chdir to</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(F) You called <tt class="command">perl -x/foo/bar</tt>, but <em class="emphasis">/foo/bar</em> is not a directory
that you can <tt class="literal">chdir</tt> to, possibly because it doesn't exist.</p>
</dd>


<dt>
<b><tt class="literal">Can't check filesystem of script "</tt><em class="replaceable">%s</em><tt class="literal">" for nosuid</tt></b>
</dt>
<dd>
<p>(P) For some reason you can't check the filesystem of the script for
<tt class="literal">nosuid</tt>.</p>
</dd>


<dt>
<b><tt class="literal">Can't coerce</tt> <em class="replaceable">%s</em> <tt class="literal">to integer in</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(F) Certain types of SVs, in particular symbol table entries
(typeglobs), can't be forced to stop being what they are.  So you
can't say things like:
<blockquote>
<pre class="programlisting">*foo += 1;</pre>
</blockquote>

You <em class="emphasis">can</em> say:
<blockquote>
<pre class="programlisting">$foo = *foo;
$foo += 1;</pre>
</blockquote>

but then <tt class="literal">$foo</tt> no longer contains a glob.</p>
</dd>


<dt>
<b><tt class="literal">Can't coerce</tt> <em class="replaceable">%s</em> <tt class="literal">to number in</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(F) Certain types of SVs, in particular symbol table entries
(typeglobs), can't be forced to stop being what they are.</p>
</dd>


<dt>
<b><tt class="literal">Can't coerce</tt> <em class="replaceable">%s</em> <tt class="literal">to string in</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(F) Certain types of SVs, in particular symbol table entries
(typeglobs), can't be forced to stop being what they are.</p>
</dd>


<dt>
<b><tt class="literal">Can't coerce array into hash</tt></b>
</dt>
<dd>
<p>(F) You used an array where a hash was expected, but the array has no
information on how to map from keys to array indices.  You can do that
only with arrays that have a hash reference at index 0.</p>
</dd>


<dt>
<b><tt class="literal">Can't create pipe mailbox</tt></b>
</dt>
<dd>
<p>(P) This is an error peculiar to VMS.  The process is suffering from exhausted
quotas or other plumbing problems.</p>
</dd>


<dt>
<b><tt class="literal">Can't declare class for non-scalar</tt> <em class="replaceable">%s</em> <tt class="literal">in "</tt><em class="replaceable">%s</em><tt class="literal">"</tt></b>
</dt>
<dd>
<p>(S) Currently, only scalar variables can declared with a specific
class qualifier in a <tt class="literal">my</tt> or <tt class="literal">our</tt> declaration.  The semantics may
be extended for other types of variables in future.</p>
</dd>


<dt>
<b><tt class="literal">Can't declare</tt> <em class="replaceable">%s</em> <tt class="literal">in "</tt><em class="replaceable">%s</em><tt class="literal">"</tt></b>
</dt>
<dd>
<p>(F) Only scalar, array, and hash variables may be declared as <tt class="literal">my</tt> or
<tt class="literal">our</tt> variables.  They must have ordinary identifiers as names.</p>
</dd>


<dt>
<b><tt class="literal">Can't do inplace edit on</tt> <em class="replaceable">%s</em><tt class="literal">:</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(S inplace) The creation of the new file failed for the indicated
reason.</p>
</dd>


<dt>
<b><tt class="literal">Can't do inplace edit without backup</tt></b>
</dt>
<dd>
<p>(F) You're on a system such as MS-DOS that gets confused if you try reading
from a deleted (but still opened) file.  You have to say <tt class="command">-i.bak</tt>, or some
such.</p>
</dd>


<dt>
<b><tt class="literal">Can't do inplace edit:</tt> <em class="replaceable">%s</em> <tt class="literal">would not be unique</tt></b>
</dt>
<dd>
<p>(S inplace) Your filesystem does not support filenames longer than 14
characters and Perl was unable to create a unique filename during
inplace editing with the <span class="option">-i</span> switch.  The file was ignored.</p>
</dd>


<dt>
<b><tt class="literal">Can't do inplace edit:</tt> <em class="replaceable">%s</em> <tt class="literal">is not a regular file</tt></b>
</dt>
<dd>
<p>(S inplace) You tried to use the <span class="option">-i</span> switch on a special file, such
as a file in <em class="emphasis">/dev</em>, or a FIFO.  The file was ignored.</p>
</dd>


<dt>
<b><tt class="literal">Can't do setegid!</tt></b>
</dt>
<dd>
<p>(P) The <tt class="literal">setegid</tt> call failed for some reason in the setuid emulator
of <em class="emphasis">suidperl</em>.</p>
</dd>


<dt>
<b><tt class="literal">Can't do seteuid!</tt></b>
</dt>
<dd>
<p>(P) The setuid emulator of <em class="emphasis">suidperl</em> failed for some reason.</p>
</dd>


<dt>
<b><tt class="literal">Can't do setuid</tt></b>
</dt>
<dd>
<p>(F) This typically means that ordinary <em class="emphasis">perl</em> tried to <tt class="literal">exec</tt><em class="emphasis">suidperl</em> to do setuid emulation, but couldn't <tt class="literal">exec</tt> it.  It looks
for a name of the form <em class="emphasis">sperl5.000</em> in the same directory that the
perl executable resides under the name <em class="emphasis">perl5.000</em>, typically
<em class="emphasis">/usr/local/bin</em> on Unix machines.  If the file is there, check the
execute permissions.  If it isn't, ask your sysadmin why not.</p>
</dd>


<dt>
<b><tt class="literal">Can't do waitpid with flags</tt></b>
</dt>
<dd>
<p>(F) This machine doesn't have either <tt class="literal">waitpid</tt> or <tt class="literal">wait4</tt>, so only
<tt class="literal">waitpid</tt> without flags is emulated.</p>
</dd>


<dt>
<b><tt class="literal">Can't do {n,m} with n &gt; m</tt></b>
</dt>
<dd>
<p>(F) Minima must be less than or equal to maxima.  If you really want
your regexp to match something 0 times, just use <tt class="literal">{0}</tt>.</p>
</dd>


<dt>
<b><tt class="literal">Can't emulate -</tt><em class="replaceable">%s</em> <tt class="literal">on #! line</tt></b>
</dt>
<dd>
<p>(F) The <tt class="literal">#!</tt> line specifies a switch that doesn't make sense at this point.
For example, it would be kind of silly to put a <span class="option">-x</span> on the <tt class="literal">#!</tt> line.</p>
</dd>


<dt>
<b><tt class="literal">Can't exec "</tt><em class="replaceable">%s</em><tt class="literal">":</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(W exec) A <tt class="literal">system</tt>, <tt class="literal">exec</tt>, or piped <tt class="literal">open</tt> call could not execute
the named program for the indicated reason.  Typical reasons include
the permissions were wrong on the file, the file wasn't found in
<tt class="literal">$ENV{PATH}</tt>, the executable in question was compiled for another
architecture, or the <tt class="literal">#!</tt> line in a script points to an interpreter that
can't be run for similar reasons.  (Or maybe your system doesn't
support <tt class="literal">#!</tt> at all.)</p>
</dd>


<dt>
<b><tt class="literal">Can't exec</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(F) Perl was trying to execute the indicated program for you because that's
what the <tt class="literal">#!</tt> line said to do.  If that's not what you wanted, you may need to
mention <tt class="literal">perl</tt> on the <tt class="literal">#!</tt> line somewhere.</p>
</dd>


<dt>
<b><tt class="literal">Can't execute</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(F) You used the <span class="option">-S</span> switch, but the copies of the script to execute found
in the <tt class="literal">PATH</tt> did not have correct permissions.</p>
</dd>


<dt>
<b><tt class="literal">Can't find</tt> <em class="replaceable">%s</em> <tt class="literal">on PATH, '.' not in PATH</tt></b>
</dt>
<dd>
<p>(F) You used the <span class="option">-S</span> switch, but the script to execute could not be found
in the <tt class="literal">PATH</tt>, or at least not with the correct permissions.  The script
exists in the current directory, but <tt class="literal">PATH</tt> prohibits running it.</p>
</dd>


<dt>
<b><tt class="literal">Can't find</tt> <em class="replaceable">%s</em> <tt class="literal">on PATH</tt></b>
</dt>
<dd>
<p>(F) You used the <span class="option">-S</span> switch, but the script to execute could not be found
in the <tt class="literal">PATH</tt>.</p>
</dd>


<dt>
<b><tt class="literal">Can't find label</tt> <em class="replaceable">%s</em></b>
</dt>
<dd>
<p>(F) You said to <tt class="literal">goto</tt> a label that isn't mentioned anywhere that
it's possible for us to go to.</p>
</dd>


<dt>
<b><tt class="literal">Can't find string terminator</tt> <em class="replaceable">%s</em> <tt class="literal">anywhere before EOF</tt></b>
</dt>
<dd>
<p>(F) Perl strings can stretch over multiple lines.  This message means that
the closing delimiter was omitted.  Because bracketed quotes count nesting
levels, the following is missing its final parenthesis:
<blockquote>
<pre class="programlisting">print q(The character '(' starts a side comment.);</pre>
</blockquote>

If you're getting this error from a here document, you may have 
included unseen whitespace before or after your closing tag. A good 
programmer's editor will have a way to help you find these characters.</p>
</dd>


<dt>
<b><tt class="literal">Can't fork</tt></b>
</dt>
<dd>
<p>(F) A fatal error occurred trying to <tt class="literal">fork</tt>.</p>
</dd>


<dt>
<b><tt class="literal">Can't get filespec - stale stat buffer?</tt></b>
</dt>
<dd>
<p>(S) This warning is peculiar to VMS.  This arises because of the difference
between access checks under VMS and under the Unix model Perl assumes. Under VMS, access checks are done by filename, rather than by bits in
the <tt class="literal">stat</tt> buffer, so that ACLs and other protections can be taken into
account.  Unfortunately, Perl assumes that the <tt class="literal">stat</tt> buffer contains
all the necessary information and passes it, instead of the filespec,
to the access-checking routine.  It will try to retrieve the filespec
using the device name and FID present in the stat buffer, but if you have made a subsequent call to the CRTL <tt class="literal">stat</tt>
routine, this won't work because the device name is overwritten with each call.  If
this warning appears, the name lookup failed and the access-checking
routine gave up and returned false, just to be conservative.  (Note:
the access-checking routine knows about the Perl <tt class="literal">stat</tt> operator and
file tests, so you shouldn't ever see this warning in response to a
Perl command; it arises only if some internal code takes stat buffers
lightly.)</p>
</dd>


<dt>
<b><tt class="literal">Can't get pipe mailbox device name</tt></b>
</dt>
<dd>
<p>(P) This error is peculiar to VMS.  After creating a mailbox to act as a
pipe, Perl can't retrieve its name for later use.</p>
</dd>


<dt>
<b><tt class="literal">Can't get SYSGEN parameter value for MAXBUF</tt></b>
</dt>
<dd>
<p>(P) This error is peculiar to VMS.  Perl asked <tt class="literal">$GETSYI</tt> how big you want
your mailbox buffers to be, and it didn't get an answer.</p>
</dd>


<dt>
<b><tt class="literal">Can't goto subroutine outside a subroutine</tt></b>
</dt>
<dd>
<p>(F) The deeply magical <tt class="literal">goto</tt><em class="replaceable">SUBROUTINE</em> call can only replace one
subroutine call for another.  It can't manufacture one out of whole
cloth.  In general, you should be calling it out of only an <tt class="literal">AUTOLOAD</tt>
routine anyway.</p>
</dd>


<dt>
<b><tt class="literal">Can't goto subroutine from an eval-string</tt></b>
</dt>
<dd>
<p>(F) The <tt class="literal">goto</tt><em class="replaceable">SUBROUTINE</em> call can't be used to jump out of an
<tt class="literal">eval</tt> string.  (You can use it to jump out of an <tt class="literal">eval</tt><em class="replaceable">BLOCK</em>,
but you probably don't want to.)</p>
</dd>