* GFORTRAN_STDERR_UNIT:: Unit number for standard error
* GFORTRAN_USE_STDERR:: Send library output to standard error
* GFORTRAN_TMPDIR:: Directory for scratch files
-* GFORTRAN_UNBUFFERED_ALL:: Don't buffer output
+* GFORTRAN_UNBUFFERED_n:: Don't buffer I/O for specific unit.
+* GFORTRAN_UNBUFFERED_ALL:: Don't buffer I/O for all units.
* GFORTRAN_SHOW_LOCUS:: Show location for runtime errors
* GFORTRAN_OPTIONAL_PLUS:: Print leading + where permitted
* GFORTRAN_DEFAULT_RECL:: Default record length for new files
GNU Fortran searches for the environment variable @env{TMP}. If
this is also missing, the default is @file{/tmp}.
+@node GFORTRAN_UNBUFFERED_n
+@section @env{GFORTRAN_UNBUFFERED_n}---Don't buffer I/O on unit n
+
+Environment variables named @env{GFORTRAN_UNBUFFERED_n}, where
+@samp{n} is an integer, control whether I/O on unit @samp{n} is
+unbuffered. If the first letter is @samp{y}, @samp{Y} or @samp{1},
+I/O is unbuffered. This will slow down small sequential reads and
+writes. If the first letter is @samp{n}, @samp{N} or @samp{0}, I/O is
+buffered. This is the default.
+
@node GFORTRAN_UNBUFFERED_ALL
-@section @env{GFORTRAN_UNBUFFERED_ALL}---Don't buffer output
+@section @env{GFORTRAN_UNBUFFERED_ALL}---Don't buffer I/O on all units
-This environment variable controls whether all output is unbuffered.
-If the first letter is @samp{y}, @samp{Y} or @samp{1}, all output is
-unbuffered. This will slow down large writes. If the first letter is
-@samp{n}, @samp{N} or @samp{0}, output is buffered. This is the
-default.
+This environment variable controls whether all I/O is unbuffered. If
+the first letter is @samp{y}, @samp{Y} or @samp{1}, all I/O is
+unbuffered. This will slow down small sequential reads and writes. If
+the first letter is @samp{n}, @samp{N} or @samp{0}, I/O is buffered.
+This is the default.
@node GFORTRAN_SHOW_LOCUS
@section @env{GFORTRAN_SHOW_LOCUS}---Show location for runtime errors