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| 1 | + // http://docs.freeswitch.org/getopt_8c-source.html |
| 2 | + /***************************************************************************** |
| 3 | + * |
| 4 | + * MODULE NAME : GETOPT.C |
| 5 | + * |
| 6 | + * COPYRIGHTS: |
| 7 | + * This module contains code made available by IBM |
| 8 | + * Corporation on an AS IS basis. Any one receiving the |
| 9 | + * module is considered to be licensed under IBM copyrights |
| 10 | + * to use the IBM-provided source code in any way he or she |
| 11 | + * deems fit, including copying it, compiling it, modifying |
| 12 | + * it, and redistributing it, with or without |
| 13 | + * modifications. No license under any IBM patents or |
| 14 | + * patent applications is to be implied from this copyright |
| 15 | + * license. |
| 16 | + * |
| 17 | + * A user of the module should understand that IBM cannot |
| 18 | + * provide technical support for the module and will not be |
| 19 | + * responsible for any consequences of use of the program. |
| 20 | + * |
| 21 | + * Any notices, including this one, are not to be removed |
| 22 | + * from the module without the prior written consent of |
| 23 | + * IBM. |
| 24 | + * |
| 25 | + * AUTHOR: Original author: |
| 26 | + * G. R. Blair (BOBBLAIR at AUSVM1) |
| 27 | + * Internet: bobblair@bobblair.austin.ibm.com |
| 28 | + * |
| 29 | + * Extensively revised by: |
| 30 | + * John Q. Walker II, Ph.D. (JOHHQ at RALVM6) |
| 31 | + * Internet: johnq@ralvm6.vnet.ibm.com |
| 32 | + * |
| 33 | + *****************************************************************************/ |
| 34 | + |
| 35 | + /****************************************************************************** |
| 36 | + * getopt() |
| 37 | + * |
| 38 | + * The getopt() function is a command line parser. It returns the next |
| 39 | + * option character in argv that matches an option character in opstring. |
| 40 | + * |
| 41 | + * The argv argument points to an array of argc+1 elements containing argc |
| 42 | + * pointers to character strings followed by a null pointer. |
| 43 | + * |
| 44 | + * The opstring argument points to a string of option characters; if an |
| 45 | + * option character is followed by a colon, the option is expected to have |
| 46 | + * an argument that may or may not be separated from it by white space. |
| 47 | + * The external variable optarg is set to point to the start of the option |
| 48 | + * argument on return from getopt(). |
| 49 | + * |
| 50 | + * The getopt() function places in optind the argv index of the next argument |
| 51 | + * to be processed. The system initializes the external variable optind to |
| 52 | + * 1 before the first call to getopt(). |
| 53 | + * |
| 54 | + * When all options have been processed (that is, up to the first nonoption |
| 55 | + * argument), getopt() returns EOF. The special option "--" may be used to |
| 56 | + * delimit the end of the options; EOF will be returned, and "--" will be |
| 57 | + * skipped. |
| 58 | + * |
| 59 | + * The getopt() function returns a question mark (?) when it encounters an |
| 60 | + * option character not included in opstring. This error message can be |
| 61 | + * disabled by setting opterr to zero. Otherwise, it returns the option |
| 62 | + * character that was detected. |
| 63 | + * |
| 64 | + * If the special option "--" is detected, or all options have been |
| 65 | + * processed, EOF is returned. |
| 66 | + * |
| 67 | + * Options are marked by either a minus sign (-) or a slash (/). |
| 68 | + * |
| 69 | + * No errors are defined. |
| 70 | + *****************************************************************************/ |
| 71 | + |
| 72 | + #include <stdio.h> /* for EOF */ |
| 73 | + #include <string.h> /* for strchr() */ |
| 74 | + |
| 75 | + /* static (global) variables that are specified as exported by getopt() */ |
| 76 | + char *optarg = NULL; /* pointer to the start of the option argument */ |
| 77 | + int optind = 1; /* number of the next argv[] to be evaluated */ |
| 78 | + int opterr = 1; /* non-zero if a question mark should be returned |
| 79 | + when a non-valid option character is detected */ |
| 80 | + char optopt = NULL; /* value of the last character we matched */ |
| 81 | + |
| 82 | + /* handle possible future character set concerns by putting this in a macro */ |
| 83 | + #define _next_char(string) (char)(*(string+1)) |
| 84 | + |
| 85 | + int getopt(int argc, char **argv, char *opstring) |
| 86 | + { |
| 87 | + static char *pIndexPosition = NULL; /* place inside current argv string */ |
| 88 | + char *pArgString = NULL; /* where to start from next */ |
| 89 | + char *pOptString; /* the string in our program */ |
| 90 | + |
| 91 | + |
| 92 | + if (pIndexPosition != NULL) { |
| 93 | + /* we last left off inside an argv string */ |
| 94 | + if (*(++pIndexPosition)) { |
| 95 | + /* there is more to come in the most recent argv */ |
| 96 | + pArgString = pIndexPosition; |
| 97 | + } |
| 98 | + } |
| 99 | + |
| 100 | + if (pArgString == NULL) { |
| 101 | + /* we didn't leave off in the middle of an argv string */ |
| 102 | + if (optind >= argc) { |
| 103 | + /* more command-line arguments than the argument count */ |
| 104 | + pIndexPosition = NULL; /* not in the middle of anything */ |
| 105 | + return EOF; /* used up all command-line arguments */ |
| 106 | + } |
| 107 | + |
| 108 | + /*--------------------------------------------------------------------- |
| 109 | + * If the next argv[] is not an option, there can be no more options. |
| 110 | + *-------------------------------------------------------------------*/ |
| 111 | + pArgString = argv[optind++]; /* set this to the next argument ptr */ |
| 112 | + |
| 113 | + if (('/' != *pArgString) && /* doesn't start with a slash or a dash? */ |
| 114 | + ('-' != *pArgString)) { |
| 115 | + --optind; /* point to current arg once we're done */ |
| 116 | + optarg = NULL; /* no argument follows the option */ |
| 117 | + pIndexPosition = NULL; /* not in the middle of anything */ |
| 118 | + return EOF; /* used up all the command-line flags */ |
| 119 | + } |
| 120 | + |
| 121 | + /* check for special end-of-flags markers */ |
| 122 | + if ((strcmp(pArgString, "-") == 0) || |
| 123 | + (strcmp(pArgString, "--") == 0)) { |
| 124 | + optarg = NULL; /* no argument follows the option */ |
| 125 | + pIndexPosition = NULL; /* not in the middle of anything */ |
| 126 | + return EOF; /* encountered the special flag */ |
| 127 | + } |
| 128 | + |
| 129 | + pArgString++; /* look past the / or - */ |
| 130 | + } |
| 131 | + |
| 132 | + if (':' == *pArgString) { /* is it a colon? */ |
| 133 | + /*--------------------------------------------------------------------- |
| 134 | + * Rare case: if opterr is non-zero, return a question mark; |
| 135 | + * otherwise, just return the colon we're on. |
| 136 | + *-------------------------------------------------------------------*/ |
| 137 | + optopt = *pArgString; |
| 138 | + return (opterr ? (int)'?' : (int)':'); |
| 139 | + } |
| 140 | + else if ((pOptString = strchr(opstring, *pArgString)) == 0) { |
| 141 | + /*--------------------------------------------------------------------- |
| 142 | + * The letter on the command-line wasn't any good. |
| 143 | + *-------------------------------------------------------------------*/ |
| 144 | + optarg = NULL; /* no argument follows the option */ |
| 145 | + pIndexPosition = NULL; /* not in the middle of anything */ |
| 146 | + optopt = *pArgString; |
| 147 | + return (opterr ? (int)'?' : (int)*pArgString); |
| 148 | + } |
| 149 | + else { |
| 150 | + /*--------------------------------------------------------------------- |
| 151 | + * The letter on the command-line matches one we expect to see |
| 152 | + *-------------------------------------------------------------------*/ |
| 153 | + if (':' == _next_char(pOptString)) { /* is the next letter a colon? */ |
| 154 | + /* It is a colon. Look for an argument string. */ |
| 155 | + if ('\0' != _next_char(pArgString)) { /* argument in this argv? */ |
| 156 | + optarg = &pArgString[1]; /* Yes, it is */ |
| 157 | + } |
| 158 | + else { |
| 159 | + /*------------------------------------------------------------- |
| 160 | + * The argument string must be in the next argv. |
| 161 | + * But, what if there is none (bad input from the user)? |
| 162 | + * In that case, return the letter, and optarg as NULL. |
| 163 | + *-----------------------------------------------------------*/ |
| 164 | + if (optind < argc) |
| 165 | + optarg = argv[optind++]; |
| 166 | + else { |
| 167 | + optarg = NULL; |
| 168 | + optopt = *pArgString; |
| 169 | + return (opterr ? (int)'?' : (int)*pArgString); |
| 170 | + } |
| 171 | + } |
| 172 | + pIndexPosition = NULL; /* not in the middle of anything */ |
| 173 | + } |
| 174 | + else { |
| 175 | + /* it's not a colon, so just return the letter */ |
| 176 | + optarg = NULL; /* no argument follows the option */ |
| 177 | + pIndexPosition = pArgString; /* point to the letter we're on */ |
| 178 | + } |
| 179 | + return (int)*pArgString; /* return the letter that matched */ |
| 180 | + } |
| 181 | + } |
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