Bottom ScienceNOTE
Create a test.txt file in the same folder/directory of the program.
PROGRAM IOFUN
IMPLICIT NONE
INTEGER i,ierror,ch
REAL,DIMENSION(100)::ARR
PRINT *, '============================================'
PRINT *, 'PROGRAM TO UNDERSTAND INPUT/OUTPUT IN A FILE [BOTTOMSCIENCE]'
PRINT *, '============================================'
PRINT *,'ENTER CHOICE 1.WRITING FILE 2.READING FILE'
READ(*,*)ch
IF (ch==1) THEN
OPEN(UNIT=1,FILE='test.txt', STATUS='UNKNOWN', ACTION='WRITE', IOSTAT=ierror)
DO i=1,10
ARR(i)=0.1*i*i
WRITE(1,*) ARR(i),ARR(i)**2
END DO
CLOSE(1)
PRINT *,'WRITTEN SUCCESSFULLY'
PRINT *,ierror !RETURNS 0 IF SUCCESSFUL & OTHER NUMBER IF FILE NOT OPENED
ELSE IF(ch==2) THEN
OPEN(UNIT=1,FILE='test.txt', STATUS='UNKNOWN', ACTION='READ',IOSTAT=ierror)
DO i=1,10
READ(1,*) ARR(i)
WRITE(*,*) ARR(i)
END DO
CLOSE(1)
ELSE
PRINT *,'WRONG CHOICE'
END IF
END PROGRAM
OUTPUT
1
WRITTEN SUCCESSFULLY
0
test.txt
0.100000001 1.00000007E-02
0.400000006 0.160000011
0.900000036 0.810000062
1.60000002 2.56000018
2.50000000 6.25000000
3.60000014 12.9600010
4.90000010 24.0100002
6.40000010 40.9600029
8.10000038 65.6100082
10.0000000 100.000000
