FORTRAN Reference Manual

Introduction to File I/O in the HP NonStop
Environment
FORTRAN Reference Manual—528615-001
5-30
List-Directed I/O
If you input a null in place of a constant, the value of the corresponding list entity is not
changed. Indicate a null using a comma as the first character in the input string or two
commas separated by blanks; for example:
READ *, j, k
Input: 2, 10 Value: 2 10
, 5 2 5
1, 7 1 7
, , 1 7
A slash value separator causes FORTRAN to treat the remaining list elements as nulls
and to discard the remainder of the current record.
READ *, j, k
Input: 10, 10 Value: 10, 10
/5 10, 10
List-Directed Output
List-directed output transfers data from storage locations specified in the I/O list to a
unit in the same way as list-directed input except that null values, slashes, repeated
constants, and apostrophes to indicate character values are not produced. The
formatter suppresses trailing zeros in the mantissa and leading zeros in the exponent.
List-directed output statements always produce a blank for carriage control as the first
character of each output record.