+/* Standalone applications should #define __GETOPT_PREFIX to an
+ identifier that prefixes the external functions and variables
+ defined in this header. When this happens, include the
+ headers that might declare getopt so that they will not cause
+ confusion if included after this file. Then systematically rename
+ identifiers so that they do not collide with the system functions
+ and variables. Renaming avoids problems with some compilers and
+ linkers. */
+#if defined __GETOPT_PREFIX && !defined __need_getopt
+# include <stdlib.h>
+# include <stdio.h>
+# include <unistd.h>
+# undef __need_getopt
+# undef getopt
+# undef getopt_long
+# undef getopt_long_only
+# undef optarg
+# undef opterr
+# undef optind
+# undef optopt
+# define __GETOPT_CONCAT(x, y) x ## y
+# define __GETOPT_XCONCAT(x, y) __GETOPT_CONCAT (x, y)
+# define __GETOPT_ID(y) __GETOPT_XCONCAT (__GETOPT_PREFIX, y)
+# define getopt __GETOPT_ID (getopt)
+# define getopt_long __GETOPT_ID (getopt_long)
+# define getopt_long_only __GETOPT_ID (getopt_long_only)
+# define optarg __GETOPT_ID (optarg)
+# define opterr __GETOPT_ID (opterr)
+# define optind __GETOPT_ID (optind)
+# define optopt __GETOPT_ID (optopt)
+#endif
+
+/* Standalone applications get correct prototypes for getopt_long and
+ getopt_long_only; they declare "char **argv". libc uses prototypes
+ with "char *const *argv" that are incorrect because getopt_long and
+ getopt_long_only can permute argv; this is required for backward
+ compatibility (e.g., for LSB 2.0.1).
+
+ This used to be `#if defined __GETOPT_PREFIX && !defined __need_getopt',
+ but it caused redefinition warnings if both unistd.h and getopt.h were
+ included, since unistd.h includes getopt.h having previously defined
+ __need_getopt.
+
+ The only place where __getopt_argv_const is used is in definitions
+ of getopt_long and getopt_long_only below, but these are visible
+ only if __need_getopt is not defined, so it is quite safe to rewrite
+ the conditional as follows:
+*/
+#if !defined __need_getopt
+# if defined __GETOPT_PREFIX
+# define __getopt_argv_const /* empty */
+# else
+# define __getopt_argv_const const
+# endif
+#endif
+