#:include "common.fypp"
#:set KINDS_TYPES = REAL_KINDS_TYPES + INT_KINDS_TYPES + CMPLX_KINDS_TYPES
module stdlib_io
!! Provides a support for file handling
!! ([Specification](../page/specs/stdlib_io.html))
use, intrinsic :: iso_fortran_env, only : input_unit
use stdlib_kinds, only: sp, dp, xdp, qp, &
int8, int16, int32, int64
use stdlib_optval, only: optval
use stdlib_ascii, only: is_blank
use stdlib_string_type, only : string_type
implicit none
private
! Public API
public :: loadtxt, savetxt, open, getline
! Private API that is exposed so that we can test it in tests
public :: parse_mode
!> Version: experimental
!>
!> Format strings with edit descriptors for each type and kind
!> ([Specification](../page/specs/stdlib_io.html))
character(*), parameter :: &
!> Format string for integers
FMT_INT = '(i0)', &
!> Format string for single precision real numbers
FMT_REAL_SP = '(es15.8e2)', &
!> Format string for souble precision real numbers
FMT_REAL_DP = '(es24.16e3)', &
!> Format string for extended double precision real numbers
FMT_REAL_XDP = '(es26.18e3)', &
!> Format string for quadruple precision real numbers
FMT_REAL_QP = '(es44.35e4)', &
!> Format string for single precision complex numbers
FMT_COMPLEX_SP = '(es15.8e2,1x,es15.8e2)', &
!> Format string for double precision complex numbers
FMT_COMPLEX_DP = '(es24.16e3,1x,es24.16e3)', &
!> Format string for extended double precision complex numbers
FMT_COMPLEX_XDP = '(es26.18e3,1x,es26.18e3)', &
!> Format string for quadruple precision complex numbers
FMT_COMPLEX_QP = '(es44.35e4,1x,es44.35e4)'
public :: FMT_INT, FMT_REAL_SP, FMT_REAL_DP, FMT_REAL_XDP, FMT_REAL_QP
public :: FMT_COMPLEX_SP, FMT_COMPLEX_DP, FMT_COMPLEX_XDP, FMT_COMPLEX_QP
!> Version: experimental
!>
!> Read a whole line from a formatted unit into a string variable
interface getline
module procedure :: getline_char
module procedure :: getline_string
module procedure :: getline_input_char
module procedure :: getline_input_string
end interface getline
interface loadtxt
!! version: experimental
!!
!! Loads a 2D array from a text file
!! ([Specification](../page/specs/stdlib_io.html#description))
#:for k1, t1 in KINDS_TYPES
module procedure loadtxt_${t1[0]}$${k1}$
#:endfor
end interface loadtxt
interface savetxt
!! version: experimental
!!
!! Saves a 2D array into a text file
!! ([Specification](../page/specs/stdlib_io.html#description_2))
#:for k1, t1 in KINDS_TYPES
module procedure savetxt_${t1[0]}$${k1}$
#:endfor
end interface
contains
#:for k1, t1 in KINDS_TYPES
subroutine loadtxt_${t1[0]}$${k1}$(filename, d, skiprows, max_rows, fmt)
!! version: experimental
!!
!! Loads a 2D array from a text file.
!!
!! Arguments
!! ---------
!!
!! Filename to load the array from
character(len=*), intent(in) :: filename
!! The array 'd' will be automatically allocated with the correct dimensions
${t1}$, allocatable, intent(out) :: d(:,:)
!! Skip the first `skiprows` lines. If skipping more rows than present, a 0-sized array will be returned. The default is 0.
integer, intent(in), optional :: skiprows
!! Read `max_rows` lines of content after `skiprows` lines.
!! A negative value results in reading all lines.
!! A value of zero results in no lines to be read.
!! The default value is -1.
integer, intent(in), optional :: max_rows
character(len=*), intent(in), optional :: fmt
character(len=:), allocatable :: fmt_
!!
!! Example
!! -------
!!
!!```fortran
!! ${t1}$, allocatable :: data(:, :)
!! call loadtxt("log.txt", data) ! 'data' will be automatically allocated
!!```
!!
!! Where 'log.txt' contains for example::
!!
!! 1 2 3
!! 2 4 6
!! 8 9 10
!! 11 12 13
!! ...
!!
integer :: s
integer :: nrow, ncol, i, ios, skiprows_, max_rows_
character(len=128) :: iomsg, msgout
skiprows_ = max(optval(skiprows, 0), 0)
max_rows_ = optval(max_rows, -1)
s = open(filename)
! determine number or rows
nrow = number_of_rows(s)
skiprows_ = min(skiprows_, nrow)
if ( max_rows_ < 0 .or. max_rows_ > (nrow - skiprows_) ) max_rows_ = nrow - skiprows_
! determine number of columns
ncol = 0
if ( skiprows_ < nrow ) ncol = number_of_columns(s, skiprows=skiprows_)
#:if 'complex' in t1
ncol = ncol / 2
#:endif
allocate(d(max_rows_, ncol))
do i = 1, skiprows_
read(s, *, iostat=ios, iomsg=iomsg)
if (ios/=0) then
write(msgout,1) trim(iomsg),i,trim(filename)
error stop trim(msgout)
end if
end do
! Default to format used for savetxt if fmt not specified.
#:if 'real' in t1
fmt_ = optval(fmt, "(*"//FMT_REAL_${k1}$(1:len(FMT_REAL_${k1}$)-1)//",:,1x))")
#:elif 'complex' in t1
fmt_ = optval(fmt, "(*"//FMT_COMPLEX_${k1}$(1:len(FMT_COMPLEX_${k1}$)-1)//",:,1x))")
#:else
fmt_ = optval(fmt, "*")
#:endif
if ( fmt_ == '*' ) then
! Use list directed read if user has specified fmt='*'
do i = 1, max_rows_
read (s,*,iostat=ios,iomsg=iomsg) d(i, :)
if (ios/=0) then
write(msgout,1) trim(iomsg),i,trim(filename)
error stop trim(msgout)
end if
enddo
else
! Otherwise pass default or user specified fmt string.
do i = 1, max_rows_
read (s,fmt_,iostat=ios,iomsg=iomsg) d(i, :)
if (ios/=0) then
write(msgout,1) trim(iomsg),i,trim(filename)
error stop trim(msgout)
end if
enddo
endif
close(s)
1 format('loadtxt: error <',a,'> reading line ',i0,' of ',a,'.')
end subroutine loadtxt_${t1[0]}$${k1}$
#:endfor
#:for k1, t1 in KINDS_TYPES
subroutine savetxt_${t1[0]}$${k1}$(filename, d)
!! version: experimental
!!
!! Saves a 2D array into a text file.
!!
!! Arguments
!! ---------
!!
character(len=*), intent(in) :: filename ! File to save the array to
${t1}$, intent(in) :: d(:,:) ! The 2D array to save
!!
!! Example
!! -------
!!
!!```fortran
!! ${t1}$ :: data(3, 2)
!! call savetxt("log.txt", data)
!!```
!!
integer :: s, i, ios
character(len=128) :: iomsg, msgout
s = open(filename, "w")
do i = 1, size(d, 1)
#:if 'real' in t1
write(s, "(*"//FMT_REAL_${k1}$(1:len(FMT_REAL_${k1}$)-1)//",:,1x))", &
#:elif 'complex' in t1
write(s, "(*"//FMT_COMPLEX_${k1}$(1:len(FMT_COMPLEX_${k1}$)-1)//",:,1x))", &
#:elif 'integer' in t1
write(s, "(*"//FMT_INT(1:len(FMT_INT)-1)//",:,1x))", &
#:else
write(s, *, &
#:endif
iostat=ios,iomsg=iomsg) d(i, :)
if (ios/=0) then
write(msgout,1) trim(iomsg),i,trim(filename)
error stop trim(msgout)
end if
end do
close(s)
1 format('savetxt: error <',a,'> writing line ',i0,' of ',a,'.')
end subroutine savetxt_${t1[0]}$${k1}$
#:endfor
integer function number_of_columns(s, skiprows)
!! version: experimental
!!
!! determine number of columns
integer,intent(in) :: s
integer, intent(in), optional :: skiprows
integer :: ios, skiprows_, i
character :: c
logical :: lastblank
skiprows_ = optval(skiprows, 0)
rewind(s)
do i = 1, skiprows_
read(s, *)
end do
number_of_columns = 0
lastblank = .true.
do
read(s, '(a)', advance='no', iostat=ios) c
if (ios /= 0) exit
if (lastblank .and. .not. is_blank(c)) number_of_columns = number_of_columns + 1
lastblank = is_blank(c)
end do
rewind(s)
end function number_of_columns
integer function number_of_rows(s) result(nrows)
!! version: experimental
!!
!! Determine the number or rows in a file
integer, intent(in)::s
integer :: ios
rewind(s)
nrows = 0
do
read(s, *, iostat=ios)
if (ios /= 0) exit
nrows = nrows + 1
end do
rewind(s)
end function number_of_rows
integer function open(filename, mode, iostat) result(u)
!! version: experimental
!!
!! Opens a file
!! ([Specification](../page/specs/stdlib_io.html#description_1))
!!
!!##### Behavior
!!
!!
!! To open a file to read:
!!
!!```fortran
!! u = open("somefile.txt") ! The default `mode` is "rt"
!! u = open("somefile.txt", "r")
!!```
!!
!! To open a file to write:
!!
!!```fortran
!! u = open("somefile.txt", "w")
!!```
!!
!! To append to the end of the file if it exists:
!!
!!```fortran
!! u = open("somefile.txt", "a")
!!```
character(*), intent(in) :: filename
character(*), intent(in), optional :: mode
integer, intent(out), optional :: iostat
character(3) :: mode_
character(:),allocatable :: action_, position_, status_, access_, form_
mode_ = parse_mode(optval(mode, ""))
select case (mode_(1:2))
case('r')
action_='read'
position_='asis'
status_='old'
case('w')
action_='write'
position_='asis'
status_='replace'
case('a')
action_='write'
position_='append'
status_='old'
case('x')
action_='write'
position_='asis'
status_='new'
case('r+')
action_='readwrite'
position_='asis'
status_='old'
case('w+')
action_='readwrite'
position_='asis'
status_='replace'
case('a+')
action_='readwrite'
position_='append'
status_='old'
case('x+')
action_='readwrite'
position_='asis'
status_='new'
case default
error stop "Unsupported mode: "//mode_(1:2)
end select
select case (mode_(3:3))
case('t')
form_='formatted'
case('b')
form_='unformatted'
case default
error stop "Unsupported mode: "//mode_(3:3)
end select
access_ = 'stream'
if (present(iostat)) then
open(newunit=u, file=filename, &
action = action_, position = position_, status = status_, &
access = access_, form = form_, &
iostat = iostat)
else
open(newunit=u, file=filename, &
action = action_, position = position_, status = status_, &
access = access_, form = form_)
end if
end function open
character(3) function parse_mode(mode) result(mode_)
character(*), intent(in) :: mode
integer :: i
character(:),allocatable :: a
logical :: lfirst(3)
mode_ = 'r t'
if (len_trim(mode) == 0) return
a=trim(adjustl(mode))
lfirst = .true.
do i=1,len(a)
if (lfirst(1) &
.and. (a(i:i) == 'r' .or. a(i:i) == 'w' .or. a(i:i) == 'a' .or. a(i:i) == 'x') &
) then
mode_(1:1) = a(i:i)
lfirst(1)=.false.
else if (lfirst(2) .and. a(i:i) == '+') then
mode_(2:2) = a(i:i)
lfirst(2)=.false.
else if (lfirst(3) .and. (a(i:i) == 't' .or. a(i:i) == 'b')) then
mode_(3:3) = a(i:i)
lfirst(3)=.false.
else if (a(i:i) == ' ') then
cycle
else if(any(.not.lfirst)) then
error stop "Wrong mode: "//trim(a)
else
error stop "Wrong character: "//a(i:i)
endif
end do
end function parse_mode
!> Version: experimental
!>
!> Read a whole line from a formatted unit into a deferred length character variable
subroutine getline_char(unit, line, iostat, iomsg)
!> Formatted IO unit
integer, intent(in) :: unit
!> Line to read
character(len=:), allocatable, intent(out) :: line
!> Status of operation
integer, intent(out), optional :: iostat
!> Error message
character(len=:), allocatable, optional :: iomsg
integer, parameter :: bufsize = 4096
character(len=bufsize) :: buffer, msg
integer :: chunk, stat
logical :: opened
if (unit /= -1) then
inquire(unit=unit, opened=opened)
else
opened = .false.
end if
if (opened) then
open(unit=unit, pad="yes", iostat=stat, iomsg=msg)
else
stat = 1
msg = "Unit is not connected"
end if
line = ""
do while (stat == 0)
read(unit, '(a)', advance='no', iostat=stat, iomsg=msg, size=chunk) buffer
if (stat > 0) exit
line = line // buffer(:chunk)
end do
if (is_iostat_eor(stat)) stat = 0
if (stat /= 0 .and. present(iomsg)) iomsg = trim(msg)
if (present(iostat)) then
iostat = stat
else if (stat /= 0) then
error stop trim(msg)
end if
end subroutine getline_char
!> Version: experimental
!>
!> Read a whole line from a formatted unit into a string variable
subroutine getline_string(unit, line, iostat, iomsg)
!> Formatted IO unit
integer, intent(in) :: unit
!> Line to read
type(string_type), intent(out) :: line
!> Status of operation
integer, intent(out), optional :: iostat
!> Error message
character(len=:), allocatable, optional :: iomsg
character(len=:), allocatable :: buffer
call getline(unit, buffer, iostat, iomsg)
line = string_type(buffer)
end subroutine getline_string
!> Version: experimental
!>
!> Read a whole line from the standard input into a deferred length character variable
subroutine getline_input_char(line, iostat, iomsg)
!> Line to read
character(len=:), allocatable, intent(out) :: line
!> Status of operation
integer, intent(out), optional :: iostat
!> Error message
character(len=:), allocatable, optional :: iomsg
call getline(input_unit, line, iostat, iomsg)
end subroutine getline_input_char
!> Version: experimental
!>
!> Read a whole line from the standard input into a string variable
subroutine getline_input_string(line, iostat, iomsg)
!> Line to read
type(string_type), intent(out) :: line
!> Status of operation
integer, intent(out), optional :: iostat
!> Error message
character(len=:), allocatable, optional :: iomsg
call getline(input_unit, line, iostat, iomsg)
end subroutine getline_input_string
end module stdlib_io
