macro/command/filetruncate.html

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<h1>filetruncate</h1>

<p>
Changes the size of a file. <em>(version 4.67 or later)</em>
</p>

<pre class="macro-syntax">
filetruncate &lt;filename&gt; &lt;size&gt;
</pre>

<h2>Remarks</h2>

<p>
Changes the &lt;size&gt; bytes of a &lt;filename&gt; file.<br>
Null characters('\0') are appended if the file is extended.<br>
</p>

<p>
The system variable "result" value is set to 0 if the file size is successfully changed. 
The system variable "result" value of -1 indicates an error.
</p>

<h2>Example</h2>

<pre class="macro-example">
; Changes 32 bytes of a file.
filetruncate 'test.exe' 32
if result = -1 then
        messagebox 'file truncate error' 'filetruncate'
else
        messagebox 'file truncate success' 'filetruncate'
endif
</pre>

<pre class="macro-example">
; Makes 8M bytes of a file containing all zero data.
size = 8*1024*1024
filetruncate 'bigfile.bin' size
</pre>

<pre class="macro-example">
; Opens a log file at the macro file directory.
getdir dir
sprintf2 filename '%s\test.log' dir
logopen filename 0 0
; Limitation of a file size
maxsize = 512
counter = 0

:loop
counter = counter + 1
sprintf2 line 'counter = %d' counter
logwrite line
logwrite #13#10
filetruncate filename maxsize
if result = -1 then
        messagebox 'file truncate error' 'filetruncate'
        goto skip
endif
if counter &gt; 32 goto skip
goto loop

:skip
logclose
</pre>

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