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 FILE_LICENCE ( GPL2_OR_LATER );
  11
  12 #include <stddef.h>
  13
  14 enum getopt_argument_requirement {
  15         /** Option does not take an argument */
  16         no_argument = 0,
  17         /** Option requires an argument */
  18         required_argument = 1,
  19         /** Option may have an argument */
  20         optional_argument = 2,
  21 };
  22
  23 /** A long option, as used for getopt_long() */
  24 struct option {
  25         /** Long name of this option */
  26         const char *name;
  27         /** Option takes an argument
  28          *
  29          * Must be one of @c no_argument, @c required_argument, or @c
  30          * optional_argument.
  31          */
  32         int has_arg;
  33         /** Location into which to store @c val, or NULL.
  34          *
  35          * See the description for @c val for more details.
  36          */
  37         int *flag;
  38         /** Value to return
  39          *
  40          * If @c flag is NULL, then this is the value that will be
  41          * returned by getopt_long() when this option is found, and
  42          * should therefore be set to the equivalent short option
  43          * character.
  44          *
  45          * If @c flag is non-NULL, then this value will be written to
  46          * the location pointed to by @flag, and getopt_long() will
  47          * return 0.
  48          */
  49         int val;
  50 };
  51
  52 extern char *optarg;
  53 extern int optind;
  54 extern int nextchar;
  55 extern int optopt;
  56
  57 extern int getopt_long ( int argc, char * const argv[], const char *optstring,
  58                          const struct option *longopts, int *longindex );
  59
  60 /**
  61  * Parse command-line options
  62  *
  63  * @v argv              Argument count
  64  * @v argv              Argument list
  65  * @v optstring         Option specification string
  66  * @ret option          Option found, or -1 for no more options
  67  *
  68  * See getopt_long() for full details.
  69  */
  70 static inline int getopt ( int argc, char * const argv[],
  71                            const char *optstring ) {
  72         static const struct option no_options[] = {
  73                 { NULL, 0, NULL, 0 }
  74         };
  75         return getopt_long ( argc, argv, optstring, no_options, NULL );
  76 }
  77
  78 /**
  79  * Reset getopt() internal state
  80  *
  81  * Due to a limitation of the POSIX getopt() API, it is necessary to
  82  * add a call to reset_getopt() before each set of calls to getopt()
  83  * or getopt_long().  This arises because POSIX assumes that each
  84  * process will parse command line arguments no more than once; this
  85  * assumption is not valid within Etherboot.  We work around the
  86  * limitation by arranging for execv() to call reset_getopt() before
  87  * executing the command.
  88  */
  89 static inline void reset_getopt ( void ) {
  90         optind = 1;
  91         nextchar = 0;
  92 }
  93
  94 #endif /* _GETOPT_H */