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    Annotation of /trunk/mkinitrd-magellan/klibc/usr/klibc/getopt.c

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    Revision 532 - (hide annotations) (download)
    Sat Sep 1 22:45:15 2007 UTC (16 years, 9 months ago) by niro
    File MIME type: text/plain
    File size: 2167 byte(s) 
    -import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
    1 niro 532 /*
    2     * getopt.c
    3     *
    4     * Simple POSIX getopt(), no GNU extensions...
    5     */
    6    
    7     #include <stdint.h>
    8     #include <unistd.h>
    9     #include <string.h>
    10    
    11     char *optarg;
    12     int optind, opterr, optopt;
    13     static struct getopt_private_state {
    14     const char *optptr;
    15     const char *last_optstring;
    16     char *const *last_argv;
    17     } pvt;
    18    
    19     int getopt(int argc, char *const *argv, const char *optstring)
    20     {
    21     const char *carg;
    22     const char *osptr;
    23     int opt;
    24    
    25     /* getopt() relies on a number of different global state
    26     variables, which can make this really confusing if there is
    27     more than one use of getopt() in the same program. This
    28     attempts to detect that situation by detecting if the
    29     "optstring" or "argv" argument have changed since last time
    30     we were called; if so, reinitialize the query state. */
    31    
    32     if (optstring != pvt.last_optstring || argv != pvt.last_argv ||
    33     optind < 1 || optind > argc) {
    34     /* optind doesn't match the current query */
    35     pvt.last_optstring = optstring;
    36     pvt.last_argv = argv;
    37     optind = 1;
    38     pvt.optptr = NULL;
    39     }
    40    
    41     carg = argv[optind];
    42    
    43     /* First, eliminate all non-option cases */
    44    
    45     if (!carg || carg[0] != '-' || !carg[1]) {
    46     return -1;
    47     }
    48    
    49     if (carg[1] == '-' && !carg[2]) {
    50     optind++;
    51     return -1;
    52     }
    53    
    54     if ((uintptr_t) (pvt.optptr - carg) > (uintptr_t) strlen(carg)) {
    55     /* Someone frobbed optind, change to new opt. */
    56     pvt.optptr = carg + 1;
    57     }
    58    
    59     opt = *pvt.optptr++;
    60    
    61     if (opt != ':' && (osptr = strchr(optstring, opt))) {
    62     if (osptr[1] == ':') {
    63     if (*pvt.optptr) {
    64     /* Argument-taking option with attached
    65     argument */
    66     optarg = (char *)pvt.optptr;
    67     optind++;
    68     } else {
    69     /* Argument-taking option with non-attached
    70     argument */
    71     if (argv[optind + 1]) {
    72     optarg = (char *)argv[optind+1];
    73     optind += 2;
    74     } else {
    75     /* Missing argument */
    76     optind++;
    77     return (optstring[0] == ':')
    78     ? ':' : '?';
    79     }
    80     }
    81     return opt;
    82     } else {
    83     /* Non-argument-taking option */
    84     /* pvt.optptr will remember the exact position to
    85     resume at */
    86     if (!*pvt.optptr)
    87     optind++;
    88     return opt;
    89     }
    90     } else {
    91     /* Unknown option */
    92     optopt = opt;
    93     if (!*pvt.optptr)
    94     optind++;
    95     return '?';
    96     }
    97     }