I want to loop over filenames in a directory ./dir1/. The files in this directory partially follow a numbered pattern, for example
and so on. The first 8 characters follow a numbered pattern, the formats are all ".dat", and the rest of the string is arbitrary. Note that the string length in the filename is not fixed. I can probably do it easily in shell script using wildcards. How do I loop over these files in Fortran 90?
Here is a complete platform-independent (but not idiot-proof!) solution to the problem (should work in Linux/Windows/Mac). Note that you will need Fortran 2008 compiler. The function getFileList(searchText,order,excludeText) in the following module will give you a list of files in the current directory (or the directory that is given in searchText). Note that searchText will be passed to the command line environment to seach for the files. So, wildcards could be used for file search. The two other arguments are optional: order determines in what order the files should be listed. Only two orders are supported in this function: name and date. The third argument excludeText is a text that you don't want to exist in any of the files to be listed by the function. On the output, the function returns a structure of type dynamicString that contains a list of all the requested files, in the order requested, each of which may have a different name length. I have enclosed a test file at the bottom of this response.
module ModFileList
implicit none
integer, parameter, private :: maxFileRecordLength = 2047
type DynamicString
character (len=:), allocatable :: record
end type DynamicString
contains
!*********************************************************************
!*********************************************************************
function getFileList(searchText,order,excludeText)
implicit none
character(len=*) , intent(in) :: searchText
character(len=*) , intent(in), optional :: order
character(len=*) , intent(in), optional :: excludeText
type(DynamicString), allocatable :: getFileList(:)
character(len=:) , allocatable :: command,filename,orderLowerCase
character(len=maxFileRecordLength) :: record
integer :: iunit,counter,iostat,nRecord,nskip
character(8) :: date
character(10) :: time
logical :: exist
if (present(order)) then
orderLowerCase = getLowerCase(order)
else
orderLowerCase = 'name'
end if
if (getSlash()=='\') then ! it's Windows cmd
if (orderLowerCase=='name') then ! ascending in name
command = 'dir /b /a-d ' // searchText
elseif (orderLowerCase=='date') then ! oldest will be first
command = 'dir /b /a-d /o:d ' // searchText
else
write(*,*) ' FATAL: In Misc@getFileList()'
write(*,*) ' The requested file order is not supported.'
write(*,*) ' order = ', orderLowerCase
write(*,*) 'Program aborted.'
end if
if (present(excludeText)) then
command = command // " | findstr /v /i " // trim(adjustl(excludeText))
end if
else
if (orderLowerCase=='name') then ! ascending in name
command = 'ls -1 ' // searchText
elseif (orderLowerCase=='date') then ! oldest will be first
command = 'ls -tr ' // searchText
else
write(*,*) ' FATAL: In Misc@getFileList()'
write(*,*) ' The requested file order is not supported.'
write(*,*) ' order = ', orderLowerCase
write(*,*) 'Program aborted.'
end if
if (present(excludeText)) then
command = command // " --ignore=" // trim(adjustl(excludeText))
end if
end if
! generate a brand new, non-existing filename
counter = 0
do
counter = counter + 1
call date_and_time(date,time)
filename = date // '_' // time // '_' // 'getFileList_' // int2str(counter) // '.temp'
inquire(file=filename,exist=exist) ! check if the file already exists
if (exist) cycle
exit
end do
call execute_command_line(command//' > '//filename)
nRecord = getNumRecordInFile(filename)
! check filename is not among records
nskip = 0
open(newunit=iunit,file=filename,status='old')
do counter = 1,nRecord
read(iunit,'(A)',iostat=iostat) record
if(iostat==0) then
if(filename==trim(adjustl(record))) nskip = nskip + 1
else
write(*,*) ' FATAL (1): In Misc@getFileList()'
write(*,*) ' Error occurred while reading file.'
write(*,*) 'Program aborted.'
stop
end if
end do
close(iunit)
allocate(getFileList(nRecord-nskip))
open(newunit=iunit,file=filename,status='old')
do counter = 1,nRecord
read(iunit,'(A)',iostat=iostat) record
if(iostat==0) then
if (filename/=trim(adjustl(record))) getFileList(counter)%record = trim(adjustl(record))
else
write(*,*) ' FATAL (2): In Misc@getFileList()'
write(*,*) ' Error occurred while reading file.'
write(*,*) 'Program aborted.'
stop
end if
end do
close(iunit)
if (getSlash()=='\') then ! it's Windows cmd
command = 'del '//filename
else
command = 'rm '//filename
end if
call execute_command_line(command)
end function getFileList
!*********************************************************************
!*********************************************************************
pure function getLowerCase(string)
implicit None
character(*), intent(in) :: string
character(len(string)) :: getLowerCase
character(26), parameter :: lowerCase = 'abcdefghijklmnopqrstuvwxyz', upperCase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
integer :: ic, i
! capitalize each letter if it is lowercase
getLowerCase = string
do i = 1, len(string)
ic = INDEX(upperCase, string(i:i))
if (ic > 0) getLowerCase(i:i) = lowerCase(ic:ic)
end do
end function getLowerCase
!*********************************************************************
!*********************************************************************
function getNumRecordInFile(filename)
implicit none
character(len=*), intent(in) :: filename
character(len=8) :: record
integer :: getNumRecordInFile,iunit,iostat
open(newunit=iunit,file=filename,status='old')
getNumRecordInFile = 0
do
read(iunit,'(A)',iostat=iostat) record
if(iostat==0) then
getNumRecordInFile = getNumRecordInFile + 1
cycle
elseif(iostat<0) then
exit
else
write(*,*) 'FATAL error occurred reading file in Misc in getNumRecordInFile().'
write(*,*) 'Program aborted.'
stop
end if
end do
close(iunit)
end function getNumRecordInFile
!*********************************************************************
!*********************************************************************
character(len=1) function getSlash()
implicit none
character(len=7) :: os
call get_environment_variable('OS',os)
if (os=='Windows') then
getSlash = '\'
else
getSlash = '/'
end if
end function getSlash
!*********************************************************************
!*********************************************************************
pure function int2str(integerIn,formatIn)
implicit none
integer , intent(in) :: integerIn
character(*), intent(in), optional :: formatIn
character(:), allocatable :: int2str
integer :: i,length
character(len=63) :: thisFormat
if (present(formatIn)) then
write(thisFormat,formatIn) integerIn
int2str = trim(adjustl(thisFormat))
else
do i=1,63
if(abs(integerIn)<10**i) then
length = i
if (integerIn<0) length = length + 1
exit
end if
end do
allocate(character(length) :: int2str)
write(thisFormat,'(1I63)') length
thisFormat = '(1I' // trim(adjustl(thisFormat)) // ')'
write(int2str,thisFormat) integerIn
end if
end function int2str
!*********************************************************************
!*********************************************************************
end module ModFileList
Here is test file for the above module:
include 'mod_FileList'
program main
use ModFileList, only: getFileList, dynamicString, int2str
implicit none
type(dynamicString), allocatable :: FileList(:), SystemInfo(:)
character(63) :: record
character(len=127) :: searchString
character(len=:), allocatable :: dir,fileName,fileBase,FileExt,test
logical :: exist
integer :: i
real*16 :: dummy
searchString = '*.f90'
FileList = getFileList(searchString)
if (size(FileList)==0) then
write(*,*) 'no file detected'
else
write(*,*) int2str(size(FileList)), " files detected containing ", trim(adjustl(searchString)), " :"
do i = 1,size(FileList)
write(*,*) FileList(i)%record
end do
end if
end program main
If you compile this test file and run it, the output should be something similar to the following:
2 files detected containing *.f90 :
main.f90
mod_FileList.f90