/*
 * ircaux.c: some extra routines... not specific to irc... that I needed 
 *
 * Written By Michael Sandrof
 *
 * Copyright (c) 1990, 1991 Michael Sandrof.
 * Copyright (c) 1991, 1992 Troy Rollo.
 * Copyright (c) 1992-2004 Matthew R. Green.
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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
 * SUCH DAMAGE.
 */

#include "irc.h"
IRCII_RCSID("@(#)$eterna: ircaux.c,v 1.94 2005/09/21 22:19:20 mrg Exp $");

#if defined(MIPS_SYSV)
# define _TERMIOS_INCLUDED
# define _INCLUDE_TERMIO
# include <sys/termio.h>
#endif /* MIPS_SYSV */

#ifdef HAVE_SYS_UN_H
#include <sys/un.h>
#endif /* HAVE_SYS_UN_H */

#ifndef _Windows
#include <pwd.h>
#endif /* _Windows */

#include "ircaux.h"
#include "output.h"
#include "ircterm.h"
#include "newio.h"
#include "server.h"

static int bind_local_addr(u_char *, u_char *, int, int);


#ifdef	ALLOC_DEBUG
# ifdef  _IBMR2
struct	HeapDesc
{
	u_long	 Link;
	u_long	 Size;
};
# endif /* _IBMR2 */
#define	ALLOC_LIST 2048
static	u_char	*MemList[ALLOC_LIST];
static	long	MemSize[ALLOC_LIST];
static	int	Init = 0;

static	void	dump_mem(void);

static	void
dump_mem()
{
	int	i;
	FILE	*fp;
# ifdef _IBMR2
	struct	HeapDesc *HeapElement;
	u_char	*lowest;
	u_char	*highest;
	long	size;
# endif /* _IBMR2 */
	int	fits;

	fp = fopen("debug.log", "w");
	fprintf(fp, "ircII failed because of a segmentation violation\nKnown allocations follow:\n\n");
	for (i = 0; i < ALLOC_LIST; i++)
		if (MemList[i])
		{
# ifdef _IBMR2
	/*
	 * The following determines if the size shown for this element of
	 * memory matches the size we have recorded in the allocation list.
	 * this is very much machine dependant, and could even vary between
	 * SysV and BSD on the same machine.
	 */
			size = (0x08 << (*((long *) MemList[i] - 1)));
			if (size - 0x08 >= MemSize[i] && (size >> 1) - 0x08<MemSize[i])
				fits = 1;
			else
				fits = 0;
#else
			fits = 1;
# endif /* _IBMR2 */
			fprintf(fp, "     %08lx  %08lx  %08lx  %08lx %s\n",
			    (long) MemList[i], MemSize[i],
			    (long) *((long *) MemList[i]-2),
			    *((long *) MemList[i]-1), fits ? "" : "SUSPICIOUS");
		}
# ifdef _IBMR2
	/*
	 * Now we'll walk the heap. We do this by finding the lowest and
         * highest elements in our list, and use the HeapDesc structure
	 * to find our way around.
	 */
	highest = NULL;
	lowest = NULL;
	for (i = 0; i < ALLOC_LIST; i++)
	{
		if (!MemList[i])
			continue;
		if (!lowest)
			lowest = MemList[i];
		if ((u_long) MemList[i] < (u_long) lowest)
			lowest = MemList[i];
		if ((u_long) MemList[i] > (u_long) highest)
			highest = MemList[i];
	}
	fprintf(fp, "\nKnown allocations start at %08x and end at %08x\n",
	    lowest, highest);
	fprintf(fp, "\nHeap walks as follows:\n\n");
	for (HeapElement = lowest-0x08; HeapElement<highest;
	    HeapElement = (HeapElement->Link == 0xefL || !HeapElement->Link)?
	    (HeapElement+(0x01<<HeapElement->Size)):
	    ((struct	HeapDesc *) HeapElement->Link))
	{
		fprintf(fp, "    %08x %08x %08x\n",
		    HeapElement + 1,
		    HeapElement->Link,
		    HeapElement->Size);
	}
# endif /* _IBMR2 */
	fclose(fp);
	fprintf(stderr, "Segmentation violation. Debug information saved to debug.log\n");

	/*
	 * If we resume on a segmentation violation, hopefully it repeats the
	 * violation and we get both our log and the core dump from the point
	 * at which things fail.
	 */
	(void) MY_SIGNAL(SIGSEGV, (sigfunc *)SIG_DFL, 0);
	return;
}
#endif /* ALLOC_DEBUG */

/*
 * new_free:  Why do this?  Why not?  Saves me a bit of trouble here and
 * there 
 */
void
new_free(iptr)
	void	*iptr;
{
	void	**ptr = (void **) iptr;
#ifdef ALLOC_DEBUG
	FILE	*fp;
	int	i;
#endif /* ALLOC_DEBUG */
#ifdef DO_USER2
	int	oldmask;
#endif /* DO_USER2 */

	/* cheap hack. */
	if (*ptr == empty_string || *ptr == zero || *ptr == one)
		*ptr = (void *) 0;
	else if (*ptr)
	{
#ifdef DO_USER2
		oldmask = sigblock(sigmask(SIGUSR2));
#endif /* DO_USER2 */
#ifdef FREE_DEBUG
		if (free(*ptr) < 0)
			put_it("*debug* free failed '%s'", (u_char *) ptr);
#else
		free(*ptr);
#endif /* FREE_DEBUG */
#ifdef DO_USER2
		sigblock(oldmask);
#endif /* DO_USER2 */
#ifdef ALLOC_DEBUG
		for (i = 0; i < ALLOC_LIST; i++)
		{
			if ((void *) MemList[i] == *ptr)
				break;
		}
		if (i == ALLOC_LIST)
		{
			fprintf(stderr,
				"Memory freed that was never allocated\n");
			fp=fopen("debug.log", "w");
			fprintf(fp, "failed by freeing %08lx\n", (long) *ptr);
			fprintf(fp, "List is as follows:\n");
			for (i = 0; i < ALLOC_LIST; i++)
				if (MemList[i])
					fprintf(fp, "    %08lx  %08lx\n",
						(long) MemList[i], MemSize[i]);
			fclose(fp);
			abort();
		}
		MemList[i] = (void *) 0;
		MemSize[i] = 0L;
#endif /* ALLOC_DEBUG */
		*ptr = (void *) 0;
	}
}

#define WAIT_BUFFER 2048
static u_char * FAR wait_pointers[WAIT_BUFFER] = {0}, **current_wait_ptr = wait_pointers;

/*
 * wait_new_free: same as new_free() except that free() is postponed.
 */
void
wait_new_free(ptr)
	u_char	**ptr;
{
	if (*current_wait_ptr)
		new_free(current_wait_ptr);
	*current_wait_ptr++ = *ptr;
	if (current_wait_ptr >= wait_pointers + WAIT_BUFFER)
		current_wait_ptr = wait_pointers;
	*ptr = (u_char *) 0;
}

/*
 * really_free: really free the data if level == 0
 */
void
really_free(level)
	int	level;
{
	if (level != 0)
		return;
	for (current_wait_ptr = wait_pointers; current_wait_ptr < wait_pointers + WAIT_BUFFER; current_wait_ptr++)
		if (*current_wait_ptr)
			new_free(current_wait_ptr);
	current_wait_ptr = wait_pointers;
}

u_char	*
new_realloc(ptr, size)
	u_char	*ptr;
	size_t	size;
{
	u_char	*new_ptr;
#ifdef ALLOC_DEBUG
	int	i;
#endif /* ALLOC_DEBUG */

	if ((new_ptr = (u_char *) realloc(ptr, size)) == (u_char *) 0)
	{
		fprintf(stderr, "realloc failed (%d): %s\nIrc Aborted!\n",
			(int)size, strerror(errno));
		exit(1);
	}
#ifdef ALLOC_DEBUG
	for (i = 0;i < ALLOC_LIST; i++)
		if ((u_char *) MemList[i] == ptr)
			break;
	if (i == ALLOC_LIST)
	{
		fprintf(stderr, "Memory freed that was never allocated");
		abort();
	}
	MemList[i] = new_ptr;
	MemSize[i] = size;
#endif /* ALLOC_DEBUG */
	return (new_ptr);
}

u_char	*
new_malloc(size)
	size_t	size;
{
	u_char	*ptr;

#ifdef	ALLOC_DEBUG
	int	i;

	if (!Init)
	{
		Init = 1;
		for (i = 0; i < ALLOC_LIST; i++)
		{
			MemList[i] = (void *) 0;
			MemSize[i] = 0L;
		}
		if (getenv("DEBUG"))
			(void) MY_SIGNAL(SIGSEGV, dump_mem, 0);
	}
#endif /* ALLOC_DEBUG */
	if ((ptr = (u_char *) malloc(size)) == (u_char *) 0)
	{
		static	char	error[] = "Malloc failed: \nIrc Aborted!\n";

		write(2, error, my_strlen(error));
		write(2, strerror(errno), my_strlen(strerror(errno)));
		term_reset();
		exit(1);
	}
#ifdef ALLOC_DEBUG
	for (i = 0; i < ALLOC_LIST && MemList[i]; i++)
		;
	if (i == ALLOC_LIST)
	{
		FILE	*fp;
		int	j;

		fprintf(stderr,
		    "Out of space in memory record. Probable memory leak\n");
		fp = fopen("debug.log", "w");
		for (i = 0; i < ALLOC_LIST; i++)
		{
			fprintf(fp, "    %08lx %08lx \"",
				(long) MemList[i], MemSize[i]);
			for (j = 0; j < MemSize[i] && j < 45; j++)
			{
				if (MemList[i][j] < 32 || MemList[i][j] > 127)
					putc('.', fp);
				else
					putc(MemList[i][j], fp);
			}
			fprintf(fp, "\"\n");
		}
		fclose(fp);
		abort();
	}
	MemList[i]=ptr;
	MemSize[i]=size;
#endif /* ALLOC_DEBUG */
	return (ptr);
}

#ifdef ALLOC_DEBUG
void
alloc_cmd(command, args, subargs)
	u_char    *command,
		*args,
		*subargs;
{
	u_char	*arg;
	int	f_count = 0,
		f_dump = 0;
	int	i, j;
	int	count;
	long	size;
	FILE	*fp;

	while ((arg = next_arg(args, &args)))
	{
		while (*arg)
		{
			switch(*arg++)
			{
			case 'c':
			case 'C':
				f_count = 1;
				break;
			case 'd':
			case 'D':
				f_dump = 1;
				break;
			}
		}
	}
	if (f_dump)
		fp = fopen("debug.log", "w");
	else
		fp = NULL;
	for (size = count = i = 0; i < ALLOC_LIST; i++)
	{
		if (fp && MemList[i])
		{
			fprintf(fp, "    %08lx %08lx \"",
				(long) MemList[i], MemSize[i]);
			for (j = 0; j < MemSize[i] && j < 45; j++)
			{
				if (MemList[i][j] < 32 || MemList[i][j] > 127)
					putc('.', fp);
				else
					putc(MemList[i][j], fp);
			}
			fprintf(fp, "\"\n");
		}
		if (MemList[i])
		{
			count++;
			size += MemSize[i];
		}
	}
	if (fp)
		fclose(fp);
	if (f_count)
	{
		say("%d blocks allocated out of %d", count, ALLOC_LIST);
		say("%ld bytes allocated, an average of %ld per block",
				size, size/count);
	}
}
#endif /* ALLOC_DEBUG */

/*
 * malloc_strcpy:  Mallocs enough space for src to be copied in to where
 * ptr points to.
 *
 * Never call this with ptr pointing to an uninitialised string, as the
 * call to new_free() might crash the client... - phone, jan, 1993.
 */
void
malloc_strcpy(ptr, src)
	u_char	**ptr;
	u_char	*src;
{
	malloc_strncpy(ptr, src, 0);
}

void
malloc_strncpy(ptr, src, extra)
	u_char	**ptr;
	u_char	*src;
	size_t	extra;
{
	/* no point doing anything else */
	if (src == *ptr)
		return;

	new_free(ptr);
	/* cheap hack. */
	if ((src == empty_string || src == zero || src == one) && extra == 0)
		*ptr = src;
	else if (src)
	{
		*ptr = new_malloc(my_strlen(src) + 1 + extra);
		my_strcpy(*ptr, src);
	}
	else
		*ptr = (u_char *) 0;
}

/* malloc_strcat: Yeah, right */
void
malloc_strcat(ptr, src)
	u_char	**ptr;
	u_char	*src;
{
	malloc_strncat(ptr, src, 0);
}

/* malloc_strncat: Yeah, right */
void
malloc_strncat(ptr, src, extra)
	u_char	**ptr;
	u_char	*src;
	size_t	extra;
{
	u_char	*new;

	if (*ptr)
	{
		new = (u_char *) new_malloc(my_strlen(*ptr) + my_strlen(src) + 1 + extra);
		my_strcpy(new, *ptr);
		my_strcat(new, src);
		new_free(ptr);
		*ptr = new;
	}
	else
		malloc_strcpy(ptr, src);
}

void
malloc_strcat_ue(ptr, src)
	u_char	**ptr;
	u_char	*src;
{
	u_char	*new;

	if (*ptr)
	{
		size_t len = my_strlen(*ptr) + my_strlen(src) + 1;

		new = (u_char *) new_malloc(len);
		my_strcpy(new, *ptr);
		strmcat_ue(new, src, len);
		new_free(ptr);
		*ptr = new;
	}
	else
		malloc_strcpy(ptr, src);
}

u_char	*
upper(s)
	u_char	*s;
{
	u_char	*t = (u_char *) 0;

	if (s)
		for (t = s; *s; s++)
			if (islower(*s))
				*s = toupper(*s);
	return (t);
}

u_char *
lower(s)
	u_char	*s;
{
	u_char	*t = (u_char *) 0;

	if (s)
		for (t = s; *s; s++)
			if (isupper(*s))
				*s = tolower(*s);
	return t;
}

/*
 * Connect_By_Number Performs a connecting to socket 'service' on host
 * 'host'.  Host can be a hostname or ip-address.  If 'host' is null, the
 * local host is assumed.   The parameter full_hostname will, on return,
 * contain the expanded hostname (if possible).  Note that full_hostname is a
 * pointer to a u_char *, and is allocated by connect_by_numbers() 
 *
 * The following special values for service exist:
 *
 * 0  Create a socket for accepting connections
 *
 * -2 Connect to the address passed in place of the hostname parameter
 *
 * Errors: 
 *
 * -1 get service failed 
 *
 * -2 get host failed 
 *
 * -3 socket call failed 
 *
 * -4 connect call failed 
 */
int
connect_by_number(service, host, nonblocking, oldres, oldres0)
	int	service;
	u_char	*host;
	int	nonblocking;
	struct addrinfo **oldres;
	struct addrinfo **oldres0;
{
	int	s = -1;
	u_char	buf[100];
	int	err = -1;
	u_char	strhost[NI_MAXHOST], strservice[NI_MAXSERV], *serv;
	SOCKADDR_STORAGE *server;
	struct addrinfo hints, *res, *res0;

	if (service == -2)
	{
		server = (SOCKADDR_STORAGE *) host;
		if (getnameinfo((struct sockaddr *)server,
		    SA_LEN((struct sockaddr *)server),
		    CP(strhost), sizeof(strhost),
		    CP(strservice), sizeof(strservice),
		    NI_NUMERICHOST|NI_NUMERICSERV))
			return -1;

		serv = strservice;
		host = strhost;
	}
	else
	{
		snprintf(CP(strservice), sizeof strservice, "%d", service);
		serv = strservice;

		if (service > 0)
		{
			if (host == (u_char *) 0)
			{
				gethostname(CP(buf), sizeof(buf));
				host = buf;
			}
		}
	}

	if (oldres && *oldres && oldres0 && *oldres0)
	{
		res = *oldres;
		res0 = *oldres0;
		*oldres = 0;
		*oldres0 = 0;
	}
	else
	{
		memset(&hints, 0, sizeof hints);
		hints.ai_flags = 0;
		hints.ai_protocol = 0;
		hints.ai_addrlen = 0;
		hints.ai_canonname = NULL;
		hints.ai_addr = NULL;
		hints.ai_next = NULL;
		if (service == -1)
			hints.ai_socktype = SOCK_DGRAM;
		else
			hints.ai_socktype = SOCK_STREAM;
		hints.ai_family = AF_UNSPEC;
		errno = 0;
		err = getaddrinfo(CP(host), CP(serv), &hints, &res0);
		if (err != 0) 
			return (-2);
		res = res0;
	}
	for (; res; res = res->ai_next) {
		err = 0;
		if ((s = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) < 0)
			continue;
		set_socket_options(s);
		if (source_host)
		{
			if (bind_local_addr(source_host, 0, s, res->ai_family) < 0)
				err = -2;
			else if (service <= 0 && service != -2 && listen(s, 1) == -1)
				err = -4;
			if (err)
				goto again;
		}
#ifdef NON_BLOCKING_CONNECTS
		if (nonblocking && set_non_blocking(s) < 0)
		{
			err = -4;
			goto again;
		}
#endif /* NON_BLOCKING_CONNECTS */
		err = connect(s, res->ai_addr, res->ai_addrlen);
		if (err < 0)
		{
			if (!(errno == EINPROGRESS && nonblocking))
			{
				err = -4;
				goto again;
			}
			/*
			 * if we're non blocking, and we got an EINPROGRESS
			 * save the res0 away so we can re-continue if this
			 * fails to connect.
			 */
			if (oldres && oldres0)
			{
				*oldres = res->ai_next;
				*oldres0 = res0;
				res0 = 0;
			}
			err = 0;
		}
again:
		if (err == 0)
			break;
		new_close(s);
	}
	if (res0)
	{
		freeaddrinfo(res0);
		res0 = 0;
	}
	if (err < 0) {
		new_close(s);
		return err;
	}
	return s;
}

/*
 * Binds to specified socket, host, port using specified family.
 * Returns:
 * 0   if everythins is OK
 * -2  if host wasn't found
 * -10 if family type wasn't supported for specified host
 */
static int
bind_local_addr(localhost, localport, fd, family)
	u_char *localhost;
	u_char *localport;
	int fd;
	int family;
{
	struct  addrinfo hintsx, *resx, *res0x;
	int     err = -1;

	memset(&hintsx, 0, sizeof(hintsx));
	hintsx.ai_family = family;
	hintsx.ai_socktype = SOCK_STREAM;
	hintsx.ai_flags = AI_PASSIVE;

	err = getaddrinfo(CP(localhost), CP(localport), &hintsx, &res0x);
	if (err != 0)
	{
# ifndef EAI_ADDRFAMILY
#  ifdef EAI_FAMILY
#   define EAI_ADDRFAMILY EAI_FAMILY
#  else
#   error "no EAI_ADDRFAMILY or EAI_FAMILY"
#  endif
# endif
		if (err == EAI_ADDRFAMILY)
			return -10;
		else
			return -2;
	}
	err = -1;
	for (resx = res0x; resx; resx = resx->ai_next)
	{
		if (bind(fd, resx->ai_addr, resx->ai_addrlen) == 0)
		{
			err = 0;
			break;
		}
	}
	freeaddrinfo(res0x);
	if (err < 0)
		return -2;
	return 0;
}

u_char	*
next_arg(str, new_ptr)
	u_char	*str,
		**new_ptr;
{
	u_char	*ptr;

	if ((ptr = sindex(str, UP("^ "))) != NULL)
	{
		if ((str = my_index(ptr, ' ')) != NULL)
			*str++ = (u_char) 0;
		else
			str = empty_string;
	}
	else
		str = empty_string;
	if (new_ptr)
		*new_ptr = str;
	return ptr;
}

u_char	*
new_next_arg(str, new_ptr)
	u_char	*str,
		**new_ptr;
{
	u_char	*ptr,
		*start;

	if ((ptr = sindex(str, UP("^ \t"))) != NULL)
	{
		if (*ptr == '"')
		{
			start = ++ptr;
			while ((str = sindex(ptr, UP("\"\\"))) != NULL)
			{
				switch (*str)
				{
				case '"':
					*str++ = '\0';
					if (*str == ' ')
						str++;
					if (new_ptr)
						*new_ptr = str;
					return (start);
				case '\\':
					if (*(str + 1) == '"')
						my_strcpy(str, str + 1);
					ptr = str + 1;
				}
			}
			str = empty_string;
		}
		else
		{
			if ((str = sindex(ptr, UP(" \t"))) != NULL)
				*str++ = '\0';
			else
				str = empty_string;
		}
	}
	else
		str = empty_string;
	if (new_ptr)
		*new_ptr = str;
	return ptr;
}

/* my_stricmp: case insensitive version of strcmp */
int
my_stricmp(str1, str2)
	u_char	*str1,
		*str2;
{
	int	xor;

	if (!str1)
		return -1;
	if (!str2)
		return 1; 
	for (; *str1 || *str2 ; str1++, str2++)
	{
		if (!*str1 || !*str2)
			return (*str1 - *str2);
		if (isalpha(*str1) && isalpha(*str2))
		{
			xor = *str1 ^ *str2;
			if (xor != 32 && xor != 0)
				return (*str1 - *str2);
		}
		else
		{
			if (*str1 != *str2)
				return (*str1 - *str2);
		}
	}
	return 0;
}

/* my_strnicmp: case insensitive version of strncmp */
int	
my_strnicmp(str1, str2, n)
	u_char	*str1,
		*str2;
	size_t	n;
{
	size_t	i;
	int	xor;

	for (i = 0; i < n; i++, str1++, str2++)
	{
		if (isalpha(*str1) && isalpha(*str2))
		{
			xor = *str1 ^ *str2;
			if (xor != 32 && xor != 0)
				return (*str1 - *str2);
		}
		else
		{
			if (*str1 != *str2)
				return (*str1 - *str2);
		}
	}
	return 0;
}

/*
 * strmcpy: Well, it's like this, strncpy doesn't append a trailing null if
 * strlen(str) == maxlen.  strmcpy always makes sure there is a trailing null 
 */
void
strmcpy(dest, src, maxlen)
	u_char	*dest,
		*src;
	size_t	maxlen;
{
	my_strncpy(dest, src, maxlen);
	dest[maxlen-1] = '\0';
}

/*
 * strmcat: like strcat, but truncs the dest string to maxlen (thus the dest
 * should be able to handle maxlen+1 (for the null)) 
 */
void
strmcat(dest, src, maxlen)
	u_char	*dest,
		*src;
	size_t	maxlen;
{
	size_t	srclen,
		len;

	srclen = my_strlen(src);
	if ((len = my_strlen(dest) + srclen) > maxlen)
		my_strncat(dest, src, srclen - (len - maxlen));
	else
		my_strcat(dest, src);
}

/*
 * strmcat_ue: like strcat, but truncs the dest string to maxlen (thus the dest
 * should be able to handle maxlen + 1 (for the null)). Also unescapes
 * backslashes.
 */
void
strmcat_ue(dest, src, maxlen)
	u_char	*dest,
		*src;
	size_t	maxlen;
{
	size_t	dstlen;

	dstlen = my_strlen(dest);
	dest += dstlen;
	maxlen -= dstlen;
	while (*src && maxlen > 0)
	{
		if (*src == '\\')
		{
			if (my_index("npr0", src[1]))
				*dest++ = '\020';
			else if (*(src + 1))
				*dest++ = *++src;
			else
				*dest++ = '\\';
		}
		else
			*dest++ = *src;
		src++;
	}
	*dest = '\0';
}

/*
 * scanstr: looks for an occurrence of str in source.  If not found, returns
 * 0.  If it is found, returns the position in source (1 being the first
 * position).  Not the best way to handle this, but what the hell 
 */
extern	int
scanstr(source, str)
	u_char	*str,
		*source;
{
	int	i,
		max;
	size_t	len;

	len = my_strlen(str);
	max = my_strlen(source) - len;
	for (i = 0; i <= max; i++, source++)
	{
		if (!my_strnicmp(source, str, len))
			return (i + 1);
	}
	return (0);
}

/* expand_twiddle: expands ~ in pathnames. */
u_char	*
expand_twiddle(str)
	u_char	*str;
{
	u_char	lbuf[BIG_BUFFER_SIZE];

	if (*str == '~')
	{
		str++;
		if (*str == '/' || *str == '\0')
		{
			my_strmcpy(lbuf, my_path, sizeof lbuf);
			my_strmcat(lbuf, str, sizeof lbuf);
		}
		else
		{
			u_char	*rest;
#ifndef _Windows
			struct	passwd *entry;
#endif /* _Windows */

			if ((rest = my_index(str, '/')) != NULL)
				*rest++ = '\0';
#ifdef _Windows
			if (GetProfileString("IRC", "StartDir", "", lbuf, sizeof lbuf))
			{
#else
			if ((entry = getpwnam(CP(str))) != NULL)
			{
				my_strmcpy(lbuf, entry->pw_dir, sizeof lbuf);
#endif /* _Windows */
				if (rest)
				{
					my_strmcat(lbuf, "/", sizeof lbuf);
					my_strmcat(lbuf, rest, sizeof lbuf);
				}
			}
			else
				return (u_char *) NULL;
		}
	}
	else
		my_strmcpy(lbuf, str, sizeof lbuf);
	str = '\0';
	malloc_strcpy(&str, lbuf);
	return (str);
}

/*
 * sindex: much like index(), but it looks for a match of any character in
 * the group, and returns that position.  If the first character is a ^, then
 * this will match the first occurence not in that group.
 */
u_char	*
sindex(string, group)
	u_char	*string,
		*group;
{
	u_char	*ptr;

	if (!string || !group)
		return (u_char *) NULL;
	if (*group == '^')
	{
		group++;
		for (; *string; string++)
		{
			for (ptr = group; *ptr; ptr++)
			{
				if (*ptr == *string)
					break;
			}
			if (*ptr == '\0')
				return string;
		}
	}
	else
	{
		for (; *string; string++)
		{
			for (ptr = group; *ptr; ptr++)
			{
				if (*ptr == *string)
					return string;
			}
		}
	}
	return (u_char *) NULL;
}

/*
 * srindex: much like rindex(), but it looks for a match of any character in
 * the group, and returns that position.  If the first character is a ^, then
 * this will match the first occurence not in that group.
 */
u_char	*
srindex(string, group)
	u_char	*string,
		*group;
{
	u_char	*ptr, *str;

	if (!string || !group)
		return (u_char *) NULL;
	str = string + my_strlen(string);
	if (*group == '^')
	{
		group++;
		for (; str != (string-1); str--)
		{
			for (ptr = group; *ptr; ptr++)
			{
				if (*ptr == *str)
					break;
			}
			if (*ptr == '\0')
				return str;
		}
	}
	else
	{
		for (; str != (string-1); str--)
		{
			for (ptr = group; *ptr; ptr++)
			{
				if (*ptr == *str)
					return str;
			}
		}
	}
	return (u_char *) NULL;
}

/* is_number: returns true if the given string is a number, false otherwise */
int
is_number(str)
	u_char	*str;
{
	while (*str == ' ')
		str++;
	if (*str == '-')
		str++;
	if (*str)
	{
		for (; *str; str++)
		{
			if (!isdigit((*str)))
				return (0);
		}
		return 1;
	}
	else
		return 0;
}

/* rfgets: exactly like fgets, cept it works backwards through a file!  */
char	*
rfgets(lbuf, size, file)
	char	*lbuf;
	int	size;
	FILE	*file;
{
	char	*ptr;
	off_t	pos;

	if (fseek(file, -2L, 1))
		return NULL;
	do
	{
		switch (fgetc(file))
		{
		case EOF:
			return NULL;
		case '\n':
			pos = ftell(file);
			ptr = fgets(lbuf, size, file);
			fseek(file, (long)pos, 0);
			return ptr;
		}
	}
	while (fseek(file, -2L, 1) == 0);
	rewind(file);
	pos = 0L;
	ptr = fgets(lbuf, size, file);
	fseek(file, (long)pos, 0);
	return ptr;
}

/*
 * path_search: given a file called name, this will search each element of
 * the given path to locate the file.  If found in an element of path, the
 * full path name of the file is returned in a static string.  If not, null
 * is returned.  Path is a colon separated list of directories 
 */
u_char	*
path_search(name, path)
	u_char	*name;
	u_char	*path;
{
	static	u_char	FAR lbuf[BIG_BUFFER_SIZE] = "";
	u_char	*ptr,
		*free_path = (u_char *) 0;

	malloc_strcpy(&free_path, path);
	path = free_path;
	while (path)
	{
#ifdef __MSDOS__
		if ((ptr = my_index(path, ';')) != NULL)
#else
		if ((ptr = my_index(path, ':')) != NULL)
#endif /* __MSDOS */
			*(ptr++) = '\0';
		lbuf[0] = 0;
		if (path[0] == '~')
		{
			my_strmcat(lbuf, my_path, sizeof lbuf);
			path++;
		}
		my_strmcat(lbuf, path, sizeof lbuf);
		my_strmcat(lbuf, "/", sizeof lbuf);
		my_strmcat(lbuf, name, sizeof lbuf);
		if (access(CP(lbuf), F_OK) == 0)
			break;
		path = ptr;
	}
	new_free(&free_path);
	return (path) ? lbuf : (u_char *) 0;
}

/*
 * double_quote: Given a str of text, this will quote any character in the
 * set stuff with the QUOTE_CHAR. It returns a malloced quoted, null
 * terminated string 
 */
u_char	*
double_quote(str, stuff)
	u_char	*str;
	u_char	*stuff;
{
	u_char	lbuf[BIG_BUFFER_SIZE];
	u_char	*ptr = NULL;
	u_char	c;
	int	pos;

	if (str && stuff)
	{
		for (pos = 0; (c = *str); str++)
		{
			if (my_index(stuff, c))
			{
				if (c == '$')
					lbuf[pos++] = '$';
				else
					lbuf[pos++] = '\\';
			}
			lbuf[pos++] = c;
		}
		lbuf[pos] = '\0';
		malloc_strcpy(&ptr, lbuf);
	}
	else
		malloc_strcpy(&ptr, str);
	return ptr;
}

#ifdef ZCAT
/* Here another interesting stuff:
 * it handle zcat of compressed files
 * You can manage compressed files in this way:
 *
 * IN: u_char *name, the compressed file FILENAME
 * OUT: a FILE *, from which read the expanded file
 *
 */
FILE	*
zcat(name)
	u_char	*name;
{
	FILE	*fp;
	int	in[2];

	in[0] = -1;
	in[1] = -1;
	if (pipe(in))
	{
		say("Unable to start decompression process: %s", strerror(errno));
		if(in[0] != -1)
		{
			new_close(in[0]);
			new_close(in[1]);
		}
		return(NULL);
	}
	switch(fork())
	{
	case -1:
		say("Unable to start decompression process: %s", strerror(errno));
		return(NULL);
	case 0:
		(void) MY_SIGNAL(SIGINT, (sigfunc *) SIG_IGN, 0);
		dup2(in[1], 1);
		new_close(in[0]);
		setuid(getuid());
		setgid(getgid());
#ifdef ZARGS
		execlp(ZCAT, ZCAT, ZARGS, name, NULL);
#else
		execlp(ZCAT, ZCAT, name, NULL);
#endif /* ZARGS */
		exit(0);
	default:
		new_close(in[1]);
		if ((fp = fdopen(in[0], "r")) == (FILE *) 0)
		{
			say("Cannot open pipe file descriptor: %s", strerror(errno));
			return(NULL);
		}
		break;
	}
	return(fp);
}
#endif /* ZCAT */

#ifdef NEED_INDEX

extern	char	*
index(s, c)
	char	*s;
	char	c;
{
# ifdef HAVE_STRSTR
	return strstr(s, c);
# else
	
	int	len = my_strlen(s);

	for (; len > 0 && c != *s; s++, len--)
		;
	return (len) ? s : (char *) NULL;
# endif /* HAVE_STRSTD */
}

#endif /* NEED_INDEX */

#ifdef NEED_RINDEX

extern	char	*
rindex(s, c)
	char	*s;
	char	c;
{
# ifdef HAVE_STRRSTR
	return strrstr(s, c);
# else

	int	len = my_strlen(s);
	char	*t = s;

	s += len;
	for (; s >= t && c != *s; s--)
		;
	return (s < t) ? (char *) NULL : s;
# endif /* HAVE_STRRSTR */
}

#endif /* NEED_RINDEX */

#ifdef NON_BLOCKING_CONNECTS
int
set_non_blocking(fd)
int	fd;
{
	int	res, nonb = 0;

#if defined(NBLOCK_POSIX)
	nonb |= O_NONBLOCK;
#else
# if defined(NBLOCK_BSD)
	nonb |= O_NDELAY;
# else
#  if defined(NBLOCK_SYSV)
	res = 1;

	if (ioctl (fd, FIONBIO, &res) < 0)
		return -1;
#  else
no idea how to set an fd to non-blocking 
#  endif /* NBLOCK_SYSV */
# endif /* NBLOCK_BSD */
#endif /* NON_POSIX */
#if (defined(NBLOCK_POSIX) || defined(NBLOCK_BSD)) && !defined(NBLOCK_SYSV)
	if ((res = fcntl(fd, F_GETFL, 0)) == -1)
		return -1;
	else if (fcntl(fd, F_SETFL, res | nonb) == -1)
		return -1;
#endif /* (NBLOCK_POSIX || NBLOCK_BSD) && !NBLOCK_SYSV */
	return 0;
}

int
set_blocking(fd)
int	fd;
{
	int	res, nonb = 0;

#if defined(NBLOCK_POSIX)
	nonb |= O_NONBLOCK;
#else
# if defined(NBLOCK_BSD)
	nonb |= O_NDELAY;
# else
#  if defined(NBLOCK_SYSV)
	res = 0;

	if (ioctl (fd, FIONBIO, &res) < 0)
		return -1;
#  else
no idea how to return an fd blocking 
#  endif /* NBLOCK_SYSV */
# endif /* NBLOCK_BSD */
#endif /* NBLOCK_POSIX */
#if (defined(NBLOCK_POSIX) || defined(NBLOCK_BSD)) && !defined(NBLOCK_SYSV)
	if ((res = fcntl(fd, F_GETFL, 0)) == -1)
		return -1;
	else if (fcntl(fd, F_SETFL, res &~ nonb) == -1)
		return -1;
#endif /* (NBLOCK_POSIX || NBLOCK_BSD) && !NBLOCK_SYSV */
	return 0;
}
#endif /* NON_BLOCKING_CONNECTS */


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