Le Sat 15/11/2003, Daniel Jacobowitz disait
> On Sat, Nov 15, 2003 at 05:13:33PM +0100, Erwan David wrote:
> >
> > File :
> >
> >
> > /****************************************************************************
> > * Includes.
> > *
> >
> > ****************************************************************************/
> > #include <stdlib.h>
> > #include <stdio.h>
> > #include <stdarg.h>
> > #include <string.h>
> > #include <unistd.h>
> >
> >
> > /****************************************************************************
> > * Parse the command-line arguments and store the requested configuration.
> > *
> >
> > ****************************************************************************/
> > static int ParseArgs(int argc, char *argv[])
> > {
> > int Option;
> >
> > while((Option=getopt(argc,argv,"h:lw:"))!=-1)
> > switch(Option)
> > {
> > }
> > }
> >
> >
> > compilation :
> >
> > cc -g -ansi -pedantic -Wall -W -Wundef -Wshadow -Wpointer-arith
> > -Wbad-function-cast -Wcast-qual -Wcast-align -Wwrite-strings
> > -Wconversion -Wstrict-prototypes -Wmissing-prototypes
> > -Wmissing-declarations -Wredundant-decls -Wnested-externs -Winline
> > -DNO_EXPOSE_COMPRESSION -I/usr/include/libart-2.0/libart_lgpl/
> > -I/usr/include/libart-2.0/ -I/usr/include/gdk-pixbuf-1.0
> > -I/usr/include/glib-1.2 -I/usr/lib/glib/include -I/usr/X11R6/include
> > -c -o main.o main.c
> > main.c: In function `ParseArgs':
> > main.c:19: warning: implicit declaration of function `getopt'
> > main.c:23: warning: control reaches end of non-void function
> > main.c: At top level:
> > main.c:16: warning: `ParseArgs' defined but not used
> >
> >
> > Why did getopt disappear ?
>
> Because you used -ansi. It's documented to turn off features that are
> incompatible with ISO C90. From man gcc-3.3:
>
> The macro "__STRICT_ANSI__" is predefined when the -ansi
> option is used. Some header files may notice this macro and
> refrain from declaring certain functions or defining cer-
> tain macros that the ISO standard doesn't call for; this is
> to avoid interfering with any programs that might use these
> names for other things.
>
> ISO C does not define getopt in unistd.h, so __STRICT_ANSI__ disables
> the prototype of getopt.
ISO C tells *nothing* about unistd.h sop, *all* functions non defined
by ISO-C should be disabled. Beginning by read, write, open and close.
--
Erwan
