程序无法写入 FORTRAN 中的文件

Question

我一直在研究 FORTRAN 并决定编写一个简单的 Blackjack 程序，将 win/loss 统计数据保存在一个文件中。问题是，每次我执行程序时，它都会写入一个新数组，而不是覆盖文件中现有的数组。

相关代码：

open(15, file='placar.dat')            !opens the file containing a (0,0,0,0) array
integer, dimension(1:4)::round=0'      !This is the array which contains the stats for a 
subroutine r(v)                        !given round, e.g.: player 1 wins and player
integer, intent(in),dimension(1:4)::v  !2 loses, round(1)=1, 
integer, dimension(1:4)::vx            !round(2)=0, round(3)=0, round(4)=1
read(15,*)vx                           !This line reads the array contained in the file to 
                                       !the array vx.
do i=1,4,1
     vx(i)=vx(i)+v(i)                  !this will add the round statistics passed to this 
end do                                 !subroutine to the vx array.
write(15,*)(vx(i),i=1,4)               !this line should overwrite the old array contained
end subroutine r                       !in the file with the new values. But this does not 
                                       !happen and a new line is written.

Answer 1

我认为您的错误是因为读取原始数组会使文件游标前进。因此，当您写回文件时，您的光标已经超过了数组。

我相信倒带（将光标设置到初始点）文件会纠正此问题：

open(15, file='placar.dat')            !opens the file containing a (0,0,0,0) array
integer, dimension(1:4)::round=0'      !This is the array which contains the stats for a 
subroutine r(v)                        !given round, e.g.: player 1 wins and player
integer, intent(in),dimension(1:4)::v  !2 loses, round(1)=1, 
integer, dimension(1:4)::vx            !round(2)=0, round(3)=0, round(4)=1
read(15,*)vx                           !This line reads the array contained in the file to 
                                       !the array vx.
do i=1,4,1
     vx(i)=vx(i)+v(i)                  !this will add the round statistics passed to this 
end do                                 !subroutine to the vx array.
rewind(15)                             !rewind file
write(15,*)(vx(i),i=1,4)               !this line should overwrite the old array contained
end subroutine r                       !in the file with the new values. But this does not 
                                       !happen and a new line is written.

但是请注意，这会覆盖从文件开头开始的内容，因此如果您在该文件中不仅有数组，它还会覆盖其他内容，可能会以某种方式使输出看起来像很奇怪。

程序无法写入 FORTRAN 中的文件

Program failing to write to a file in FORTRAN

arrays

fortran

file

overwrite