pg_getopt_ctx.c

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/*-------------------------------------------------------------------------
 *
 * pg_getopt_ctx.c
 *    Thread-safe implementation of getopt()
 *
 * Copyright (c) 1987, 1993, 1994
 *  The Regents of the University of California.  All rights reserved.
 *
 * 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 of the University 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 REGENTS 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 REGENTS 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
 *
 * IDENTIFICATION
 *    src/port/pg_getopt_ctx.c
 *
 *-------------------------------------------------------------------------
 */
 
#include "c.h"
 
#include "port/pg_getopt_ctx.h"
 
#define BADCH   (int)'?'
#define BADARG  (int)':'
#define EMSG    ""
 
/*
 * Start parsing argc/argv argument vector.
 *
 * This is a re-entrant version of the standard library getopt(3) function.
 * To use, first call pg_getopt_start() to initialize the state, and then call
 * pg_getopt_next() until it returns -1.
 */
void
pg_getopt_start(pg_getopt_ctx *ctx, int nargc, char *const *nargv, const char *ostr)
{
    ctx->nargc = nargc;
    ctx->nargv = nargv;
    ctx->ostr = ostr;
 
    ctx->optind = 1;
    ctx->optarg = NULL;
    ctx->opterr = 1;            /* Caller may clear this after the call */
    ctx->optopt = 0;
 
    ctx->place = EMSG;          /* option letter processing */
}
 
/*
 * Parse next option in argc/argv argument vector
 */
int
pg_getopt_next(pg_getopt_ctx *ctx)
{
    const char *oli;            /* option letter list index */
 
    if (!*ctx->place)
    {                           /* update scanning pointer */
        if (ctx->optind >= ctx->nargc || *(ctx->place = ctx->nargv[ctx->optind]) != '-')
        {
            ctx->place = EMSG;
            return -1;
        }
        if (ctx->place[1] && *++ctx->place == '-' && ctx->place[1] == '\0')
        {                       /* found "--" */
            ++ctx->optind;
            ctx->place = EMSG;
            return -1;
        }
    }                           /* option letter okay? */
    if ((ctx->optopt = (int) *ctx->place++) == (int) ':' ||
        !(oli = strchr(ctx->ostr, ctx->optopt)))
    {
        /*
         * if the user didn't specify '-' as an option, assume it means -1.
         */
        if (ctx->optopt == (int) '-')
        {
            ctx->place = EMSG;
            return -1;
        }
        if (!*ctx->place)
            ++ctx->optind;
        if (ctx->opterr && *ctx->ostr != ':')
            (void) fprintf(stderr,
                           "illegal option -- %c\n", ctx->optopt);
        return BADCH;
    }
    if (*++oli != ':')
    {                           /* don't need argument */
        ctx->optarg = NULL;
        if (!*ctx->place)
            ++ctx->optind;
    }
    else
    {                           /* need an argument */
        if (*ctx->place)        /* no white space */
            ctx->optarg = ctx->place;
        else if (ctx->nargc <= ++ctx->optind)
        {                       /* no arg */
            ctx->place = EMSG;
            if (*ctx->ostr == ':')
                return BADARG;
            if (ctx->opterr)
                (void) fprintf(stderr,
                               "option requires an argument -- %c\n",
                               ctx->optopt);
            return BADCH;
        }
        else
            /* white space */
            ctx->optarg = ctx->nargv[ctx->optind];
        ctx->place = EMSG;
        ++ctx->optind;
    }
    return ctx->optopt;         /* dump back option letter */
}