.help istable Aug91 noao.ptools.digiphot
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NAME
istable --  determine the status of a file

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USAGE
istable infile

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PARAMETERS

.ls infile
The name of the input file whose status is to be determined.
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.ls table = no
An output variable which is "yes" if \fIinfile\fR is an STSDAS table
and "no" otherwise.
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.ls text = no
An output variable which is "yes" if \fIinfile\fR is an APPHOT/DAOPHOT
text database and "no" otherwise.
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.ls other = no
An output variable which is "yes" if \fIinfile\fR is neither of the
above and "no" otherwise.
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DESCRIPTION
ISTABLE is a very simple task which determines whether a specified
input file is an STSDAS table, an APPHOT/DAOPHOT text database file or 
neither of the above. ISTABLE first tries to open the input file as an 
STSDAS table. If successful ISTABLE returns "yes" in the
variable \fItable\fR and "no" in \fItext\fR and \fIother\fR. Otherwise
ISTABLE  tries to open the input file as an APPHOT/DAOPHOT text database
file by checking for the "#K IRAF" keyword.
If the check is positive ISTABLE return "yes" in
the variable \fItext\fR and "no" in \fItable\fR and \fIother\fR. If the input
file is neither an STSDAS table or an APPHOT/DAOPHOT text database
ISTABLE returns "yes" in the variable \fIother\fR and "no" in \fItext\fR
and \fItable\fR.

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EXAMPLES

1. Determine whether the file n4147.mag.1 is an STSDAS table.

.nf
   pt> istable n4147.mag
   pt> =istable.table

       ... answer will appear on the screen
.fi

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TIME REQUIREMENTS
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BUGS
Users should be wary of running ISTABLE in background as the output
CL parameters may not be properly updated. 
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SEE ALSO
.endhelp