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<P><FONT SIZE="5">9.9 Eneo</FONT><BR>
<P>The <SAMP>eneo</SAMP> command takes one filename argument.
If the file does not exist, no action is taken. If the file
does exist, it is deleted. In both cases success status is
returned. However, if the file exists and cannot be deleted,
<SAMP>eneo</SAMP> returns severe status.
<P>
<PRE>
Syntax : eneo = "eneo" s filename
Examples: eneo result.out
</PRE>
<P>The <SAMP>eneo</SAMP> command was added so as to allow
regression testing scripts to ensure that existing output
files were not present before proceeding with a test run. If
FunnelWeb were to fail to generate an output file, it would
be extremely undesirable for the old version to be used.
<P>ENEO stands for <STRONG>E</STRONG>stablish the <STRONG>N</STRONG>on
<STRONG>E</STRONG>xistence <STRONG>O</STRONG>f. Most operating systems provide a
command to delete files. Typically these commands are verbs
such as "delete", "remove", and
"kill". As a consequence, the designers of delete
commands usually consider the command to have failed if it
fails to find the file to be deleted. However, in scripts,
the delete command is very commonly used to
<I>establish the non-existence of</I> one or more files.
Typically, a script is starting up and needs to clear the
air before getting started. If the files are there, they
should be deleted; if they are not, then that's OK
too. (Note: As far as I know, the <SAMP>eneo</SAMP> command
is original).
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