Re: Checking datatype of CHAR variable in 4GL

jparker@epsilon.com wrote: > What I don't like about this approach is that it is time consuming. > Anytime you ask 4gl to wander through a string you're wasting time. Not a > big deal when you're talking onsey-twosey, but when this is a core > algorithm for thousands or millions of records/rows it can get quite > expensive. Much better to call a 'c' routine in these cases. > > cheers > j. Sigh, Try this. #include <stdio.h> #include <stdlib.h> #include <strings.h> #include <ctypes.h> /* If not already defined */ #define TRUE 1 #define FALSE 0 int is_num( char *string) { char *ptr; int flag, len; flag = TRUE; ptr = string; len = strlen(string); while ( flag && len) { if ( (isdigit(*ptr) == 0)) flag = FALSE; ptr++; len -= 1; } return (flag); } Caveats: I wrote it so use it at your own peril! This was written on the fly and hasn't been tested. In other words, it aint kosher! So play with this code.