catch(3Tcl)

NAME
     catch - Evaluate script and trap exceptional returns

SYNOPSIS
     catch script ?varName?


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