diff options
Diffstat (limited to 'nuttx/lib/lib_getopt.c')
| -rw-r--r-- | nuttx/lib/lib_getopt.c | 65 |
1 files changed, 38 insertions, 27 deletions
diff --git a/nuttx/lib/lib_getopt.c b/nuttx/lib/lib_getopt.c index 31ba31f66..c75d1d7f5 100644 --- a/nuttx/lib/lib_getopt.c +++ b/nuttx/lib/lib_getopt.c @@ -1,7 +1,7 @@ /**************************************************************************** * lib/lib_getopt.c * - * Copyright (C) 2007-2009 Gregory Nutt. All rights reserved. + * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt <spudmonkey@racsa.co.cr> * * Redistribution and use in source and binary forms, with or without @@ -85,7 +85,7 @@ static bool g_binitialized = false; * If there are no more option characters, getopt() returns -1. Then optind * is the index in argv of the first argv-element that is not an option. * - * The 'optstring argument is a string containing the legitimate option + * The 'optstring' argument is a string containing the legitimate option * characters. If such a character is followed by a colon, this indicates * that the option requires an argument. If an argument is required for an * option so getopt() places a pointer to the following text in the same @@ -104,6 +104,19 @@ static bool g_binitialized = false; * first character in optstring: if it is ':', then ':' is returned; * otherwise '?' is returned. * + * Assumptions: + * - getopt() uses global varialbles and, hence, can only be used on a single + * thread. + * - This version of getopt() implements a state machine with certain, strict + * rules. If these rules are not obeyed, the state machine will get out of + * sync and incorrect results will occur. The rules: + * 1. getopt() must be called repeatedly until a terminating value is + * returned. Terminating values include: {-1, ?, : }. + * 2. After a terminating value is returned, getopt() resets the global + * data and is ready for the next command line. + * 3. If the program chooses to violate rule #1, it may do so if it sets + * optind == -1. + * ****************************************************************************/ int getopt(int argc, FAR char *const argv[], FAR const char *optstring) @@ -162,9 +175,6 @@ int getopt(int argc, FAR char *const argv[], FAR const char *optstring) /* There are no more arguments, we are finished */ g_binitialized = false; - - /* Return -1 with optind == all of the arguments */ - return ERROR; } @@ -176,38 +186,38 @@ int getopt(int argc, FAR char *const argv[], FAR const char *optstring) { /* The argument does not start with '-', we are finished */ - g_optptr = NULL; g_binitialized = false; - - /* Return the -1 with optind set to the non-option argument */ - return ERROR; } /* Skip over the '-' */ g_optptr++; - } - /* Special case handling of "-" and "-:" */ + /* Special case handling of "-" */ - if (!*g_optptr) - { - optopt = '\0'; /* We'll fix up g_optptr the next time we are called */ - return '?'; - } + if (!*g_optptr) + { + optopt = '\0'; + g_binitialized = false; + return '?'; + } + } - /* Handle the case of "-:" */ + /* Handle the case of ":" or '?' in the option list. We need to pick + * these off so that the return values cannot be confused with errors. + */ - if (*g_optptr == ':') + if (*g_optptr == ':' || *g_optptr == '?') { - optopt = ':'; - g_optptr++; + optopt = *g_optptr; + g_binitialized = false; return '?'; } - /* g_optptr now points at the next option and it is not something crazy. - * check if the option is in the list of valid options. + /* g_optptr now points at the next option and it is not something crazy + * (like NULL or ? or :). Check if the option is in the list of valid + * options. */ optchar = strchr(optstring, *g_optptr); @@ -216,7 +226,7 @@ int getopt(int argc, FAR char *const argv[], FAR const char *optstring) /* No this character is not in the list of valid options */ optopt = *g_optptr; - g_optptr++; + g_binitialized = false; return '?'; } @@ -232,7 +242,9 @@ int getopt(int argc, FAR char *const argv[], FAR const char *optstring) return *optchar; } - /* Yes. Is the required argument after the command in this same argument? */ + /* Yes... It has a required argument. Is the required argument after + * the command in this same argument? + */ if (g_optptr[1] != '\0') { @@ -258,12 +270,11 @@ int getopt(int argc, FAR char *const argv[], FAR const char *optstring) /* No argument was supplied */ - optarg = NULL; optopt = *optchar; - optind++; + g_binitialized = false; return noarg_ret; } - optind = 1; + g_binitialized = false; return ERROR; } |