src/include/getopt.h

   1 #ifndef _GETOPT_H
   2 #define _GETOPT_H
   3
   4 /** @file
   5  *
   6  * Parse command-line options
   7  *
   8  */
   9
  10 #include <stddef.h>
  11
  12 enum getopt_argument_requirement {
  13         /** Option does not take an argument */
  14         no_argument = 0,
  15         /** Option requires an argument */
  16         required_argument = 1,
  17         /** Option may have an argument */
  18         optional_argument = 2,
  19 };
  20
  21 /** A long option, as used for getopt_long() */
  22 struct option {
  23         /** Long name of this option */
  24         const char *name;
  25         /** Option takes an argument
  26          *
  27          * Must be one of @c no_argument, @c required_argument, or @c
  28          * optional_argument.
  29          */
  30         int has_arg;
  31         /** Location into which to store @c val, or NULL.
  32          *
  33          * See the description for @c val for more details.
  34          */
  35         int *flag;
  36         /** Value to return
  37          *
  38          * If @c flag is NULL, then this is the value that will be
  39          * returned by getopt_long() when this option is found, and
  40          * should therefore be set to the equivalent short option
  41          * character.
  42          *
  43          * If @c flag is non-NULL, then this value will be written to
  44          * the location pointed to by @flag, and getopt_long() will
  45          * return 0.
  46          */
  47         int val;
  48 };
  49
  50 extern char *optarg;
  51 extern int optind;
  52 extern int nextchar;
  53 extern int optopt;
  54
  55 extern int getopt_long ( int argc, char * const argv[], const char *optstring,
  56                          const struct option *longopts, int *longindex );
  57
  58 /**
  59  * Parse command-line options
  60  *
  61  * @v argv              Argument count
  62  * @v argv              Argument list
  63  * @v optstring         Option specification string
  64  * @ret option          Option found, or -1 for no more options
  65  *
  66  * See getopt_long() for full details.
  67  */
  68 static inline int getopt ( int argc, char * const argv[],
  69                            const char *optstring ) {
  70         static const struct option no_options[] = {
  71                 { NULL, 0, NULL, 0 }
  72         };
  73         return getopt_long ( argc, argv, optstring, no_options, NULL );
  74 }
  75
  76 /**
  77  * Reset getopt() internal state
  78  *
  79  * Due to a limitation of the POSIX getopt() API, it is necessary to
  80  * add a call to reset_getopt() before each set of calls to getopt()
  81  * or getopt_long().  This arises because POSIX assumes that each
  82  * process will parse command line arguments no more than once; this
  83  * assumption is not valid within Etherboot.  We work around the
  84  * limitation by arranging for execv() to call reset_getopt() before
  85  * executing the command.
  86  */
  87 static inline void reset_getopt ( void ) {
  88         optind = 1;
  89         nextchar = 0;
  90 }
  91
  92 #endif /* _GETOPT_H */