How to read number of lines in Fortran 90 from a text file?

Question

How to read number of lines present in a text file.

My text file seems to be like:

1
2
3
.
.
.
n

Answer 1

Although unclear, but i think, if you just have to know the number lines in the files, just use wc -l in the command line

if you want to do anything further, just read the number of lines a character string and count until the end of file is encountered. here is the code below

character :: inputline*200

OPEN(lin, file=inputfile, status='old', action='read', position='rewind')

loop1: DO
READ(lin,*,iostat=eastat) inputline
IF (eastat < 0) THEN
    numvalues = numvalues + 1
WRITE(*,*) trim(inputfile), ' :number of records =', numvalues-1
EXIT loop1

ELSE IF (eastat > 0) THEN
    STOP 'IO-error'
ENDIF
    numvalues = numvalues + 1 

END DO loop1

hope that helps!