/**************************************************************************** * libc/unistd/lib_getopt.c * * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /**************************************************************************** * Global Variables ****************************************************************************/ FAR char *optarg; /* Optional argument following option */ int optind = 1; /* Index into argv */ int optopt = '?'; /* unrecognized option character */ /**************************************************************************** * Private Variables ****************************************************************************/ static FAR char *g_optptr = NULL; static bool g_binitialized = false; /**************************************************************************** * Global Functions ****************************************************************************/ /**************************************************************************** * Name: getopt * * Description: getopt() parses command-line arguments. Its arguments argc * and argv are the argument count and array as passed to the main() * function on program invocation. An element of argv that starts with * '-' is an option element. The characters of this element (aside from * the initial '-') are option characters. If getopt() is called repeatedly, * it returns successively each of the option characters from each of the * option elements. * * If getopt() finds another option character, it returns that character, * updating the external variable optind and a static variable nextchar so * that the next call to getopt() can resume the scan with the following * option character or argv-element. * * 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 * 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 * argv-element, or the text of the following argv-element, in optarg. * * NOTES: * 1. opterr is not supported and this implementation of getopt() never * printfs error messages. * 2. getopt is NOT threadsafe! * 3. This version of getopt() does not reset global variables until * -1 is returned. As a result, your command line parsing loops * must call getopt() repeatedly and continue to parse if other * errors are returned ('?' or ':') until getopt() finally returns -1. * (You can also set optind to -1 to force a reset). * * Return: If an option was successfully found, then getopt() returns the * option character. If all command-line options have been parsed, then * getopt() returns -1. If getopt() encounters an option character that * was not in optstring, then '?' is returned. If getopt() encounters an * option with a missing argument, then the return value depends on the * first character in optstring: if it is ':', then ':' is returned; * otherwise '?' is returned. * ****************************************************************************/ int getopt(int argc, FAR char *const argv[], FAR const char *optstring) { if (argv && optstring && argc > 1) { int noarg_ret = '?'; char *optchar; /* The inital value of optind is 1. If getopt() is called again in the * program, optind must be reset to some value <= 1. */ if (optind < 1 || !g_binitialized) { optind = 1; /* Skip over the program name */ g_optptr = NULL; /* Start at the beginning of the first argument */ g_binitialized = true; /* Now we are initialized */ } /* If the first character of opstring s ':', then ':' is in the event of * a missing argument. Otherwise '?' is returned. */ if (*optstring == ':') { noarg_ret = ':'; optstring++; } /* Are we resuming in the middle, or at the end of a string of arguments? * g_optptr == NULL means that we are started at the beginning of argv[optind]; * *g_optptr == \0 means that we are starting at the beginning of optind+1 */ while (!g_optptr || !*g_optptr) { /* We need to start at the beginning of the next argv. Check if we need * to increment optind */ if (g_optptr) { /* Yes.. Increment it and check for the case where where we have * processed everything in the argv[] array. */ optind++; } /* Check for the end of the argument list */ g_optptr = argv[optind]; if (!g_optptr) { /* There are no more arguments, we are finished */ g_binitialized = false; return ERROR; } /* We are starting at the beginning of argv[optind]. In this case, the * first character must be '-' */ if (*g_optptr != '-') { /* The argument does not start with '-', we are finished */ g_binitialized = false; return ERROR; } /* Skip over the '-' */ g_optptr++; } /* Special case handling of "-" and "-:" */ if (!*g_optptr) { optopt = '\0'; /* We'll fix up g_optptr the next time we are called */ return '?'; } /* Handle the case of "-:" */ if (*g_optptr == ':') { optopt = ':'; g_optptr++; 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. */ optchar = strchr(optstring, *g_optptr); if (!optchar) { /* No this character is not in the list of valid options */ optopt = *g_optptr; g_optptr++; return '?'; } /* Yes, the character is in the list of valid options. Does it have an * required argument? */ if (optchar[1] != ':') { /* No, no arguments. Just return the character that we found */ g_optptr++; return *optchar; } /* Yes, it has a required argument. Is the required argument * immediately after the command in this same argument? */ if (g_optptr[1] != '\0') { /* Yes, return a pointer into the current argument */ optarg = &g_optptr[1]; optind++; g_optptr = NULL; return *optchar; } /* No.. is the optional argument the next argument in argv[] ? */ if (argv[optind+1] && *argv[optind+1] != '-') { /* Yes.. return that */ optarg = argv[optind+1]; optind += 2; g_optptr = NULL; return *optchar; } /* No argument was supplied */ optarg = NULL; optopt = *optchar; optind++; return noarg_ret; } /* Restore the initial, uninitialized state */ g_binitialized = false; optind = 1; optopt = '?'; return ERROR; }