FORTRAN Reference Manual

Language Elements
FORTRAN Reference Manual—528615-001
2-4
Compiler Directives
You cannot use continuation lines to continue comments. Write multi-line comments as
multiple comment lines, as shown in the following example:
* This is such a lengthy comment line that I am afraid
* I shall have to continue it over several lines.
Compiler Directives
Designate compiler directives by placing a question mark (?) in column one, followed
by the directive name. For example:
?SYNTAX
DIMENSION A(100),B(100)
COMMON A
.
100 STOP
END
You can write more than one directive on a line by inserting a comma between
directives. The following directive lines are equivalent:
?ANSI, PAGE "This is the first page"
?ANSI
?PAGE "This is the first page"
Some directives can occupy multiple lines. Begin each line that continues a directive
with a question mark in the first column. For example:
?SOURCE routines (probability, random, trig, volume,
?combinations, permutations)
Note that some directives must be written last on a directive line. For more information
about using directives, see Section 10, Compiler Directives. The compiler ignores
blanks in directives, except within character constants.
Treatment of Blanks in a Program Line
The FORTRAN compiler ignores blanks in columns 1 through 5, and in columns 7
through the end of the line of initial and continuation lines of all statements, except
within character and Hollerith constants. The following two statements are equivalent;
both assign the value 5 to the variable READN:
read n = 5
readn=5