8.3.5 Default Field Descriptor Parameters

If you write the field descriptors I, O, Z, F, E, D, G, L, or A without specifying a field width value w, the system supplies default values for w. For the field descriptors F, E, G, and D, the system also supplies default values for d (the number of characters to the right of the decimal point), and e (the number of characters in the exponent).

The default values in Table 8-4 are based on the data type of the I/O list element.

Table 8-4 Default Field Descriptor Values

Field Descriptor  List Element  w 
I, O, Z  BYTE, INTEGER*1, LOGICAL*1  7 
I, O, Z  INTEGER*2, LOGICAL*2  7 
I, O, Z  INTEGER*4, LOGICAL*4  12 
I, O, Z  INTEGER*8[1], LOGICAL*8[1]  23 
O, Z  REAL*4  12 
O, Z  REAL*8  23 
O, Z  REAL*16[2]  44 
O, Z  CHARACTER*n  MAX(7, 3*n) 
L  LOGICAL*1, LOGICAL*2 LOGICAL*4, LOGICAL*8[1]  2 
F, E, G, D  REAL*4, COMPLEX*8  15   d: 7     e: 2 
F, E, G, D  REAL*8, COMPLEX*16  25   d: 16   e: 2 
F, E, G, D  REAL*16[2]  42   d: 33   e: 3 
A  LOGICAL*1  1 
A  LOGICAL*2, INTEGER*2  2 
A  LOGICAL*4, INTEGER*4  4 
A  LOGICAL*8[1], INTEGER*8[1]  8 
A  REAL*4, COMPLEX*8  4 
A  REAL*8, COMPLEX*16  8 
A  REAL*16[2]  16 
A  CHARACTER*n  n 

[1] Alpha only
[2] VMS, U*X

For the A field descriptor, the default is the actual length of the corresponding I/O list element.


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