VALPKGE - routines to handle variables of type Value

vtoi		cast Value variable as an int
vtol		cast Value variable as a long
vtof		cast Value variable as a float
vtod		cast Value variable as a double
atoval		convert ascii to Value
valtoabs	take absolute value of a Value variable
valcmp		compare Value variables
printfval	printf a Value variable
fprintfval	fprintf a Value variable
scanfval	scanf a Value variable
printftype	printf for the type of a segy header word

Function Prototypes:
int vtoi(register cwp_String type, Value val);
long vtol(register cwp_String type, Value val);
float vtof(register cwp_String type, Value val);
double vtod(register cwp_String type, Value val);
void atoval(cwp_String type, cwp_String keyval, Value *valp);
Value valtoabs(cwp_String type, Value val);
int valcmp(register cwp_String type, Value val1, Value val2);
void printfval(register cwp_String type, Value val);
void fprintfval(FILE *stream, register cwp_String type, Value val);
void scanfval(register cwp_String type, Value *valp);

Notes:
A Value is defined by the following in .../su/include/su.h:

typedef union { * storage for arbitrary type *
	char s[8];
	short h;
	unsigned short u;
	long l;
	unsigned long v;
	int i;
	unsigned int p;
	float f;
	double d;
	unsigned int U:16;
	unsigned int P:32;
} Value;

The use of the valpkge routines, as well as the hdrpkge routines,
permits the user to change the definition of the types of the 
various fields of the segy data type, without breaking codes that
look at part or all of these fields.

Authors: CWP: Jack K. Cohen, Shuki Ronen