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<h3 class="section">2.8 Influencing runtime behavior</h3>
<p><a name="index-options_002c-runtime-206"></a>
These options affect the runtime behavior of programs compiled with GNU Fortran.
<dl>
<dt><code>-fconvert=</code><var>conversion</var><dd><a name="index-g_t_0040code_007bfconvert_003d_007d_0040var_007bconversion_007d-207"></a>Specify the representation of data for unformatted files. Valid
values for conversion are: ‘<samp><span class="samp">native</span></samp>’, the default; ‘<samp><span class="samp">swap</span></samp>’,
swap between big- and little-endian; ‘<samp><span class="samp">big-endian</span></samp>’, use big-endian
representation for unformatted files; ‘<samp><span class="samp">little-endian</span></samp>’, use little-endian
representation for unformatted files.
<p><em>This option has an effect only when used in the main program.
The </em><code>CONVERT</code><em> specifier and the GFORTRAN_CONVERT_UNIT environment
variable override the default specified by </em><samp><span class="option">-fconvert</span></samp><em>.</em>
<br><dt><code>-fno-range-check</code><dd><a name="index-g_t_0040code_007bfno_002drange_002dcheck_007d-208"></a>Disable range checking of input values during integer <code>READ</code> operations.
For example, GNU Fortran will give an error if an input value is
outside of the relevant range of [<code>-HUGE()</code>:<code>HUGE()</code>]. In other words,
with <code>INTEGER (kind=4) :: i</code> , attempting to read -2147483648 will
give an error unless <samp><span class="option">-fno-range-check</span></samp> is given.
<br><dt><code>-frecord-marker=</code><var>length</var><dd><a name="index-g_t_0040code_007bfrecord_002dmarker_003d_007d_0040var_007blength_007d-209"></a>Specify the length of record markers for unformatted files.
Valid values for <var>length</var> are 4 and 8. Default is 4.
<em>This is different from previous versions of </em><samp><span class="command">gfortran</span></samp>,
which specified a default record marker length of 8 on most
systems. If you want to read or write files compatible
with earlier versions of <samp><span class="command">gfortran</span></samp>, use <samp><span class="option">-frecord-marker=8</span></samp>.
<br><dt><code>-fmax-subrecord-length=</code><var>length</var><dd><a name="index-g_t_0040code_007bfmax_002dsubrecord_002dlength_003d_007d_0040var_007blength_007d-210"></a>Specify the maximum length for a subrecord. The maximum permitted
value for length is 2147483639, which is also the default. Only
really useful for use by the gfortran testsuite.
<br><dt><code>-fsign-zero</code><dd><a name="index-g_t_0040code_007bfsign_002dzero_007d-211"></a>When enabled, floating point numbers of value zero with the sign bit set
are written as negative number in formatted output and treated as
negative in the <code>SIGN</code> intrinsic. <code>fno-sign-zero</code> does not
print the negative sign of zero values and regards zero as positive
number in the <code>SIGN</code> intrinsic for compatibility with F77.
Default behavior is to show the negative sign.
</dl>
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