/*===========================================================================

 Copyright (c) 1998-2000, The Santa Cruz Operation 

 All rights reserved.

 Redistribution and use in source and binary forms, with or without

 modification, are permitted provided that the following conditions are met:

 *Redistributions of source code must retain the above copyright notice,

 this list of conditions and the following disclaimer.

 *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.

 *Neither name of The Santa Cruz Operation 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 COPYRIGHT HOLDERS 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 SUCH

 DAMAGE. 

 =========================================================================*/

/* vpinit - initialize vpdirs or update vpdirs based on currentdir */

#include <stdio.h>	/* stderr */

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include "vp.h"

#include "alloc.h"

#include "library.h"

#include "global.h"

#include "constants.h"

#if !NOMALLOC

char	**vpdirs;	/* directories (including current) in view path */

#else

char	vpdirs[MAXDIR][DIRLEN + 1];

#define	MAXVPATH (MAXDIR * (DIRLEN + 1))

#endif

int	vpndirs;	/* number of directories in view path */

void

vpinit(char *current_dir)

{

	char	*suffix;	/* path from view path node */

	char	*vpath;		/* VPATH environment variable value */

	char	buf[MAXPATH + 1];

	int	i;

	char	*s;

#if NOMALLOC

	char	*node;		/* view path node */

	char	vpathbuf[MAXVPATH + 1];

#endif

	/* if an existing directory list is to be updated, free it */

	if (current_dir != NULL && vpndirs > 0) {

#if !NOMALLOC

		for (i = 0; i < vpndirs; ++i) {

			free(vpdirs[i]);

		}

		free(vpdirs);

#endif

		vpndirs = 0;

	}

	/* return if the directory list has been computed */

	/* or there isn't a view path environment variable */

	if (vpndirs > 0 || (vpath = getenv("VPATH")) == NULL ||

	    *vpath == '\0') {

		return;

	}

	/* if not given, get the current directory name */

	if (current_dir == NULL && (current_dir = getcwd(buf, MAXPATH)) == NULL) {

		(void) fprintf(stderr, "%s: cannot get current directory name\n", argv0);

		return;

	}

	/* see if this directory is in the first view path node */

	for (i = 0; vpath[i] == current_dir[i] && vpath[i] != '\0'; ++i) {

		;

	}

	if ((vpath[i] != ':' && vpath[i] != '\0') ||

	    (current_dir[i] != '/' && current_dir[i] != '\0')) {

		return;

	}

	suffix = &current_dir[i];

#if !NOMALLOC

	/* count the nodes in the view path */

	vpndirs = 1;

	for (i = 0; vpath[i] != '\0'; ++i) {

		if (vpath[i] == ':' && vpath[i + 1]) {

			++vpndirs;

		}

	}

	/* create the source directory list */

	vpdirs = mymalloc(vpndirs * sizeof(*vpdirs));

	/* don't change VPATH in the environment */

	vpath = my_strdup(vpath);

	/* split the view path into nodes */

	for (i = 0, s = vpath; *s != '\0'; ++i) {

		vpdirs[i] = s;

		while (*s != '\0' && *++s != ':') {

			if (*s == '\n') {

				*s = '\0';

			}

		}

		if (*s != '\0') {

			*s++ = '\0';

		}

	}

	/* convert the view path nodes to directories */

	for (i = 0; i < vpndirs; ++i) {

		s = mymalloc(strlen(vpdirs[i]) + strlen(suffix) + 1);

		(void) strcpy(s, vpdirs[i]);

		(void) strcat(s, suffix);

		vpdirs[i] = s;

	}

	free(vpath);

#else

	/* don't change VPATH in the environment */

	if (strlen(vpath) > MAXVPATH) {

		(void) fprintf(stderr, "%s: VPATH is longer than %d characters: %s\n", argv0, MAXVPATH, vpath);

		return;

	}

	(void) strcpy(vpathbuf, vpath);

	s = vpathbuf;

	/* convert the view path nodes to directories */

	while (*s != '\0') {

		/* get the next node */

		node = s;

		while (*s != '\0' && *++s != ':') {

			if (*s == '\n') {

				*s = '\0';

			}

		}

		if (*s != '\0') {

			*s++ = '\0';

		}

		/* ignore a directory that is too long */

		if (strlen(node) + strlen(suffix) > DIRLEN) {

			(void) fprintf(stderr, "%s: VPATH directory is longer than %d characters: %s%s\n", argv0, DIRLEN, node, suffix);

		}

		else if (vpndirs >= MAXDIR) {

			(void) fprintf(stderr, "%s: VPATH has more than %d nodes\n", argv0, vpndirs);

			return;

		}

		else {

			/* create the view path directory */

			(void) strcpy(vpdirs[vpndirs], node);

			(void) strcat(vpdirs[vpndirs], suffix);

			++vpndirs;

		}

	}

#endif

}