(g77.info) Exclamation Point

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(g77.info) Double Quote Meaning

(g77.info) VXT Fortran

 
 Meaning of Exclamation Point in Column 6
 ----------------------------------------
 
    `g77' treats an exclamation point (`!') in column 6 of a fixed-form
 source file as a continuation character rather than as the beginning of
 a comment (as it does in any other column) when the `-fvxt' option is
 specified.
 
    The following program, when run, prints a message indicating whether
 it is interpreted according to GNU Fortran (and Fortran 90) rules or
 VXT Fortran rules:
 
      C234567  (This line begins in column 1.)
            I = 0
           !1
            IF (I.EQ.0) PRINT *, ' I am a VXT Fortran program'
            IF (I.EQ.1) PRINT *, ' I am a Fortran 90 program'
            IF (I.LT.0 .OR. I.GT.1) PRINT *, ' I am a HAL 9000 computer'
            END
 
    (In the GNU Fortran and Fortran 90 languages, exclamation point is a
 valid character and, unlike space (<SPC>) or zero (`0'), marks a line
 as a continuation line when it appears in column 6.)
 

Info Catalog

(g77.info) Double Quote Meaning

(g77.info) VXT Fortran