/* $NetBSD: signalnumber.c,v 1.3 2020/08/20 22:56:56 kre Exp $ */

/*
 * Software available to all and sundry without limitations
 * but without warranty of fitness for any purpose whatever.
 *
 * Licensed for any use, including redistribution in source
 * and binary forms, with or without modifications, subject
 * the following agreement:
 *
 * Licensee agrees to indemnify licensor, and distributor, for
 * the full amount of any any claim made by the licensee against
 * the licensor or distributor, for any action that results from
 * any use or redistribution of this software, plus any costs
 * incurred by licensor or distributor resulting from that claim.
 *
 * This licence must be retained with the software.
 */

#include "namespace.h"

#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

/*
 * signalnumber()
 *
 *      Converts the signal named "name" to its
 *      signal number.
 *
 *      "name" can be the signal name with or without
 *      the leading "SIG" prefix, and character comparisons
 *      are done in a case independent manner.
 *      (ie: SIGINT == INT == int == Int == SiGiNt == (etc).)
 *
 * Returns:
 *      0 on error (invalid signal name)
 *      otherwise the signal number that corresponds to "name"
 */

int
signalnumber(const char *name)
{
        int i;
#ifndef SMALL
        long offs;
        char *ep;
#endif

        if (strncasecmp(name, "sig", 3) == 0)
                name += 3;

        for (i = 1; i < NSIG; ++i)
                if (sys_signame[i] != NULL &&
                    strcasecmp(name, sys_signame[i]) == 0)
                        return i;

#ifndef SMALL
        if (strncasecmp(name, "rtm", 3) == 0) {
                name += 3;
                if (strncasecmp(name, "ax", 2) == 0)
                        i = SIGRTMAX;
                else if (strncasecmp(name, "in", 2) == 0)
                        i = SIGRTMIN;
                else
                        return 0;
                name += 2;
                if (name[0] == '\0')
                        return i;
                if (i == SIGRTMAX && name[0] != '-')
                        return 0;
                if (i == SIGRTMIN && name[0] != '+')
                        return 0;
                if (!isdigit((unsigned char)name[1]))
                        return 0;
                offs = strtol(name+1, &ep, 10);
                if (ep == name+1 || *ep != '\0' ||
                    offs < 0 || offs > SIGRTMAX-SIGRTMIN)
                        return 0;
                if (name[0] == '+')
                        i += (int)offs;
                else
                        i -= (int)offs;
                if (i >= SIGRTMIN && i <= SIGRTMAX)
                        return i;
        }
#endif
        return 0;
}