Programming

$ man gcc

GCC(1)                                GNU                               GCC(1)



NAME
       gcc - GNU project C and C++ compiler

SYNOPSIS
       gcc [-c|-S|-E] [-std=standard]
           [-g] [-pg] [-Olevel]
           [-Wwarn...] [-pedantic]
           [-Idir...] [-Ldir...]
           [-Dmacro[=defn]...] [-Umacro]
           [-foption...] [-mmachine-option...]
           [-o outfile] infile...

       Only the most useful options are listed here; see below for the remain-
       der.  g++ accepts mostly the same options as gcc.

...

       -std=
           Determine the language standard.  This option is currently only
           supported when compiling C or C++.  A value for this option must be
           provided; possible values are

           c89
           iso9899:1990
               ISO C90 (same as -ansi).

           iso9899:199409
               ISO C90 as modified in amendment 1.

           c99
           c9x
           iso9899:1999
           iso9899:199x
               ISO C99.  Note that this standard is not yet fully supported;
               see <http://gcc.gnu.org/gcc-4.1/c99status.html> for more infor-
               mation.  The names c9x and iso9899:199x are deprecated.

           gnu89
               Default, ISO C90 plus GNU extensions (including some C99 fea-
               tures).

           gnu99
           gnu9x
               ISO C99 plus GNU extensions.  When ISO C99 is fully implemented
               in GCC, this will become the default.  The name gnu9x is depre-
               cated.

           c++98
               The 1998 ISO C++ standard plus amendments.

           gnu++98
               The same as -std=c++98 plus GNU extensions.  This is the
               default for C++ code.

           Even when this option is not specified, you can still use some of
           the features of newer standards in so far as they do not conflict
           with previous C standards.  For example, you may use "__restrict__"
           even when -std=c99 is not specified.

           The -std options specifying some version of ISO C have the same
           effects as -ansi, except that features that were not in ISO C90 but
           are in the specified version (for example, // comments and the
           "inline" keyword in ISO C99) are not disabled.