GETPOSITION(g1;g2;x) for each unit, if the string in the text
g2 occurs as a substring of the string in the text
g1, this returns the position at which the substring starts; otherwise it returns the value zero. The text
g2 may contain a single string (to be checked against every string of
g1). The structure
x (scalar or variate) supplies a logical value to indicate whether to ignore the case of any letters; if
x is omitted, the logical is assumed to be false (case not ignored).
Updated on December 4, 2017