catch (n)
Evaluate script and trap exceptional returns
SYNOPSIS
DESCRIPTION
The catch command may be used to prevent errors from aborting
command interpretation. Catch calls the Tcl interpreter recursively
to execute script, and always returns a TCL_OK code, regardless of
any errors that might occur while executing script. The return
value from catch is a decimal string giving the
code returned by the Tcl interpreter after executing script.
This will be 0 (TCL_OK) if there were no errors in script;
otherwise
it will have a non-zero value corresponding to one of the exceptional
return codes (see tcl.h for the definitions of code values). If the
varName argument is given, then it gives the name of a variable;
catch will set the variable to the string returned
from script (either a result or an error message).
Note that catch catches all exceptions, including those
generated by break and continue as well as errors.
KEYWORDS
catch, error
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