The variable-to-string conversion function must convert the variable from its base type (int, long int, float, string, etc.) to its string representation and place this string in the string buffer. The size of the string buffer is based on the length of the field picture.
The handling of protected characters in the picture string must respect the setting of the PICSKIP field option.
After all processing is completed, the string buffer must contain an exact image of the information that is to appear in the field in standard C string format. The variable-to-string conversion function should also check that the resulting string representation of the variable fits in the field.
