/*
 *	aegis - project change supervisor
 *	Copyright (C) 1994, 1996, 2002-2004 Peter Miller;
 *	All rights reserved.
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: impliment missing functions from <string.h>
 */

#include <ac/stdio.h>
#include <ac/string.h>
#include <ac/signal.h>


/*
 *  NAME
 *      strerror - string for error number
 *
 *  SYNOPSIS
 *      char *strerror(int errnum);
 *
 *  DESCRIPTION
 *      The strerror function maps the error number in errnum to an error
 *      message string.
 *
 *  RETURNS
 *      The strerror function returns a pointer to the string, the contents of
 *      which are implementation-defined.  The array pointed to shall not be
 *      modified by the program, but may be overwritten by a subsequent call to
 *      the strerror function.
 *
 *  CAVEAT
 *      Unknown errors will be rendered in the form "Error %d", where %d will
 *      be replaced by a decimal representation of the error number.
 */

#ifndef HAVE_STRERROR

char *
strerror(int n)
{
    extern int	sys_nerr;
    extern char	*sys_errlist[];
    static char	buffer[16];

    if (n < 1 || n > sys_nerr)
    {
	sprintf(buffer, "Error %d", n);
	return buffer;
    }
    return sys_errlist[n];
}

#endif /* !HAVE_STRERROR */


#ifndef HAVE_STRCASECMP

int
strcasecmp(const char *s1, const char *s2)
{
    unsigned char   c1;
    unsigned char   c2;

    for (;;)
    {
	c1 = *s1++;
	if (isupper((unsigned char)c1))
	    c1 = tolower(c1);
	c2 = *s2++;
	if (isupper((unsigned char)c2))
	    c2 = tolower(c2);
	if (c1 != c2)
	{
	    /*
	     * if s1 is a leading substring of s2, must
	     * return -1, even if the next character of s2
	     * is negative.
	     */
	    if (!c1)
		return -1;
	    if (!c2)
		return 1;
	    if (c1 < c2)
		return -1;
	    return 1;
	}
	if (!c1)
	    return 0;
    }
}

#endif /* !HAVE_STRCASECMP */


#ifndef HAVE_STRNCASECMP

int
strncasecmp(const char *s1, const char *s2, size_t len)
{
    unsigned char   c1;
    unsigned char   c2;

    while (len-- > 0)
    {
	c1 = *s1++;
	if (isupper((unsigned char)c1))
		c1 = tolower(c1);
	c2 = *s2++;
	if (isupper((unsigned char)c2))
	    c2 = tolower(c2);
	if (c1 != c2)
	{
	    /*
	     * if s1 is a leading substring of s2, must
	     * return -1, even if the next character of s2
	     * is negative.
	     */
	    if (!c1)
		return -1;
	    if (!c2)
		return 1;
	    if (c1 < c2)
		return -1;
	    return 1;
	}
	if (!c1)
	    return 0;
    }
    return 0;
}

#endif /* !HAVE_STRNCASECMP */


#ifndef HAVE_STRSIGNAL

char *
strsignal(int n)
{
    static char     buffer[16];

    switch (n)
    {
#ifdef SIGHUP
    case SIGHUP:
	return "hang up [SIGHUP]";
#endif /* SIGHUP */

#ifdef SIGINT
    case SIGINT:
	return "user interrupt [SIGINT]";
#endif /* SIGINT */

#ifdef SIGQUIT
    case SIGQUIT:
	return "user quit [SIGQUIT]";
#endif /* SIGQUIT */

#ifdef SIGILL
    case SIGILL:
	return "illegal instruction [SIGILL]";
#endif /* SIGILL */

#ifdef SIGTRAP
    case SIGTRAP:
	return "trace trap [SIGTRAP]";
#endif /* SIGTRAP */

#ifdef SIGIOT
    case SIGIOT:
	return "abort [SIGIOT]";
#endif /* SIGIOT */

#ifdef SIGEMT
    case SIGEMT:
	return "EMT instruction [SIGEMT]";
#endif /* SIGEMT */

#ifdef SIGFPE
    case SIGFPE:
	return "floating point exception [SIGFPE]";
#endif /* SIGFPE */

#ifdef SIGKILL
    case SIGKILL:
	return "kill [SIGKILL]";
#endif /* SIGKILL */

#ifdef SIGBUS
    case SIGBUS:
	return "bus error [SIGBUS]";
#endif /* SIGBUS */

#ifdef SIGSEGV
    case SIGSEGV:
	return "segmentation violation [SIGSEGV]";
#endif /* SIGSEGV */

#ifdef SIGSYS
    case SIGSYS:
	return "bad argument to system call [SIGSYS]";
#endif /* SIGSYS */

#ifdef SIGPIPE
    case SIGPIPE:
	return "write on a pipe with no one to read it [SIGPIPE]";
#endif /* SIGPIPE */

#ifdef SIGALRM
    case SIGALRM:
	return "alarm clock [SIGALRM]";
#endif /* SIGALRM */

#ifdef SIGTERM
    case SIGTERM:
	return "software termination [SIGTERM]";
#endif /* SIGTERM */

#ifdef SIGUSR1
    case SIGUSR1:
	return "user defined signal one [SIGUSR1]";
#endif /* SIGUSR1 */

#ifdef SIGUSR2
    case SIGUSR2:
	return "user defined signal two [SIGUSR2]";
#endif /* SIGUSR2 */

#ifdef SIGCLD
    case SIGCLD:
	return "death of child [SIGCLD]";
#endif /* SIGCLD */

#ifdef SIGPWR
    case SIGPWR:
	return "power failure [SIGPWR]";
#endif /* SIGPWR */

    default:
	sprintf(buffer, "signal %d", n);
	return buffer;
    }
}

#endif /* !HAVE_STRSIGNAL */

#ifndef HAVE_STRVERSCMP

/*
 * Derived from sources marked...
 *
 * Compare strings while treating digits characters numerically.
 * Copyright (C) 1997 Free Software Foundation, Inc.
 * This file is part of the GNU C Library.
 * Contributed by Jean-Franc,ois Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
 *
 * The GNU C Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * The GNU C Library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the GNU C Library; see the file COPYING.LIB.  If not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <ac/ctype.h>

/*
 * states:
 * S_N: normal,
 * S_I: comparing integral part,
 * S_F: comparing fractionnal parts,
 * S_Z: idem but with leading Zeroes only
 */
#define  S_N    0x0
#define  S_I    0x4
#define  S_F    0x8
#define  S_Z    0xC

/*
 * result_type:
 * CMP: return diff;
 * LEN: compare using len_diff/diff
 */
#define  CMP    2
#define  LEN    3


/*
 * Compare S1 and S2 as strings holding indices/version numbers, returning
 * less than, equal to or greater than zero if S1 is less than, equal
 * to or greater than S2 (for more info, see the texinfo doc).
 */

int
strverscmp(const char *s1, const char *s2)
{
    const unsigned char *p1;
    const unsigned char *p2;
    unsigned char   c1;
    unsigned char   c2;
    int		    state;
    int		    diff;

    /* Symbol(s)    others  [0-9]        0  (padding)
       Transition   (00) x  (01) d  (10) 0  (11) -   */
    static const unsigned int next_state[] =
    {
	/* state         x       d       0       - */
	/* S_N */      S_N,    S_I,    S_Z,    S_N,
	/* S_I */      S_N,    S_I,    S_I,    S_I,
	/* S_F */      S_N,    S_F,    S_F,    S_F,
	/* S_Z */      S_N,    S_F,    S_Z,    S_Z
    };

    static const int result_type[] =
    {
    /* state   x/x  x/d	 x/0  x/-  d/x	d/d  d/0  d/-
    	       0/x  0/d	 0/0  0/-  -/x	-/d  -/0  -/- */
    /* S_N */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
	       CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
    /* S_I */  CMP,  -1,  -1, CMP,  +1, LEN, LEN, CMP,
	        +1, LEN, LEN, CMP, CMP, CMP, CMP, CMP,
    /* S_F */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
	       CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
    /* S_Z */  CMP,  +1,  +1, CMP,  -1, CMP, CMP, CMP,
	        -1, CMP, CMP, CMP
    };

    p1 = (const unsigned char *)s1;
    p2 = (const unsigned char *)s2;
    if (p1 == p2)
	return 0;
    c1 = *p1++;
    c2 = *p2++;
    /* Hint: '0' is a digit too.  */
    state = S_N | ((c1 == '0') + (isdigit(c1) != 0));
    while ((diff = c1 - c2) == 0 && c1 != '\0')
    {
	state = next_state[state];
	c1 = *p1++;
	c2 = *p2++;
	state |= (c1 == '0') + (isdigit(c1) != 0);
    }
    state = result_type[state << 2 | (((c2 == '0') + (isdigit(c2) != 0)))];
    switch (state)
    {
    case CMP:
	return diff;

    case LEN:
	while (isdigit(*p1++))
	{
	    if (!isdigit(*p2++))
		return 1;
	}
	return isdigit(*p2) ? -1 : diff;

    default:
	return state;
    }
}

#endif /* !HAVE_STRVERSCMP */
