more systematic handling of colored output

isatty for Fortran needs to translate the units/file descriptors

src/C_routines.c

@@ -94,6 +94,10 @@ int stderr_isatty_c(){
   return isatty(STDERR_FILENO);
 }
 
+int stdin_isatty_c(){
+  return isatty(STDIN_FILENO);
+}
+
 
 #ifdef FYAML
 void to_flow_c(char **flow, long* length_flow, const char *mixed){

src/IO.f90

@@ -438,25 +438,23 @@ end function IO_strAsBool
 
 
 !--------------------------------------------------------------------------------------------------
-!> @brief Set foreground and/or background color.
+!> @brief Return string to set foreground and/or background color.
-!> @details Only active if unit is a TTY. Does nothing for MSC.Marc or when writing to log file.
+!> @details Only active if unit is a TTY. Does nothing for MSC.Marc. No color disables formatting.
 !> @details https://stackoverflow.com/questions/4842424
 !--------------------------------------------------------------------------------------------------
 function IO_color(fg,bg,unit)
 
   character(len=:), allocatable :: IO_color
-  integer, intent(in), dimension(3), optional :: fg, bg
+  integer, intent(in), dimension(3), optional :: &
+    fg, &                                                                                           !< foreground color (8 bit RGB)
+    bg                                                                                              !< background color (8 bit RGB)
   integer, intent(in), optional :: unit                                                             !< output unit (default STDOUT)
 
-  integer :: unit_
-
 
   IO_color = ''
 
-#if !(defined(MARC4DAMASK) || defined(LOGFILE))
+#ifndef MARC4DAMASK
-  unit_ = misc_optional(unit,IO_STDOUT)
+  if (.not. isatty(misc_optional(unit,IO_STDOUT))) return
-  if (unit_ == IO_STDOUT .and. .not. STDOUT_isatty()) return
-  if (unit_ == IO_STDERR .and. .not. STDERR_isatty()) return
 
   if (present(fg)) &
     IO_color = IO_color//achar(27)//'[38;2;'//IO_intAsStr(fg(1))//';' &

src/system_routines.f90

@@ -21,8 +21,7 @@ module system_routines
     signalint_C, &
     signalusr1_C, &
     signalusr2_C, &
-    STDOUT_isatty, &
+    isatty, &
-    STDERR_isatty, &
     f_c_string, &
     free_C
 
@@ -107,6 +106,14 @@ module system_routines
       integer(C_INT) :: stderr_isatty_C
     end function stderr_isatty_C
 
+    function stdin_isatty_C() bind(C)
+      use, intrinsic :: ISO_C_Binding, only: C_INT
+
+      implicit none(type,external)
+      integer(C_INT) :: stdin_isatty_C
+    end function stdin_isatty_C
+
+
   end interface
 
 contains
@@ -246,23 +253,28 @@ end function f_c_string
 
 
 !--------------------------------------------------------------------------------------------------
-!> @brief
+!> @brief Test whether a file descriptor refers to a terminal.
+!> @detail A terminal is neither a file nor a redirected STDOUT/STDERR/STDIN.
 !--------------------------------------------------------------------------------------------------
-logical function STDOUT_isatty()
+logical function isatty(unit)
 
-  STDOUT_isatty = merge(.true.,.false.,stdout_isatty_C()==1)
+  integer, intent(in) :: unit
-
-end function STDOUT_isatty
 
 
-!--------------------------------------------------------------------------------------------------
+  select case(unit)
-!> @brief
+#ifndef LOGFILE
-!--------------------------------------------------------------------------------------------------
+    case (OUTPUT_UNIT)
-logical function STDERR_isatty()
+      isatty = stdout_isatty_C()==1
+    case (ERROR_UNIT)
+      isatty = stderr_isatty_C()==1
+#endif
+    case (INPUT_UNIT)
+      isatty = stdin_isatty_C()==1
+    case default
+      isatty = .false.
+  end select
 
-  STDERR_isatty = merge(.true.,.false.,stderr_isatty_C()==1)
+end function isatty
-
-end function STDERR_isatty
 
 
 !--------------------------------------------------------------------------------------------------