STRMESSAGE Function

Returns the text of the error message specified by the input error number.

Usage

result = STRMESSAGE(errno)

Input Parameters

The error number for which the message text is desired.

Returned Value

The text of the error message specified by errno.

Keywords

Discussion

This function is especially useful in conjunction with the !Err system variable, which always contains the error number of the last error.

However, you should take care not to make the assumption in your programs that certain error numbers always correspond to certain error messages, as this correspondence may change as PV-WAVE is modified over time.

Example

The following procedure uses function STRMESSAGE to display the error message associated with an input/output error trapped by procedure ON_IOERROR.

FUNCTION READ_DATA, file_name

; Define a function to read, and return a 100-element, floating-point

; array.

ON_IOERROR, bad

; Declare error label.

OPENR, unit, file_name, /Get_Lun

; Open the file and use the Get_Lun keyword to allocate a logical file

; unit.

a = FLTARR(100)

; Define data array.

READU, unit, a

; Read data.

GOTO, DONE

; Clean up and return.

bad:

; Exception label.

PRINT, STRMESSAGE(!ERROR)

; Print the error message associated with the error number in

; !ERROR. Note that STRMESSAGE is used to display the message.

DONE:
FREE_LUN, unit

; Close and free the input/output unit.

RETURN, a

; Return the result. Variable a is undefined if an error occurred.

END

See Also

System Variables: !Err, !Err_String

For more information on error handling, see Chapter 10, Programming with PV-WAVE, in the PV-WAVE Programmer's Guide.

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