/* * Copyright (c) 2000, 2001 by Martin C. Shepherd. *  * All rights reserved. *  * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, and/or sell copies of the Software, and to permit persons * to whom the Software is furnished to do so, provided that the above * copyright notice(s) and this permission notice appear in all copies of * the Software and that both the above copyright notice(s) and this * permission notice appear in supporting documentation. *  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. *  * Except as contained in this notice, the name of a copyright holder * shall not be used in advertising or otherwise to promote the sale, use * or other dealings in this Software without prior written authorization * of the copyright holder. */#include <stdio.h>#include <stdlib.h>#include <limits.h>#include <errno.h>#include <string.h>#include <ctype.h>#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include "pathutil.h"/*....................................................................... * Create a new PathName object. * * Output: *  return  PathName *  The new object, or NULL on error. */PathName *_new_PathName(void){  PathName *path;  /* The object to be returned *//* * Allocate the container. */  path = (PathName *)malloc(sizeof(PathName));  if(!path) {    fprintf(stderr, "_new_PathName: Insufficient memory.\n");    return NULL;  };/* * Before attempting any operation that might fail, initialize the * container at least up to the point at which it can safely be passed * to _del_PathName(). */  path->name = NULL;  path->dim = 0;/* * Figure out the maximum length of an expanded pathname. */  path->dim = _pu_pathname_dim();  if(path->dim == 0)    return _del_PathName(path);/* * Allocate the pathname buffer. */  path->name = (char *)malloc(path->dim * sizeof(char));  if(!path->name) {    fprintf(stderr,	  "_new_PathName: Insufficient memory to allocate pathname buffer.\n");    return _del_PathName(path);  };  return path;}/*....................................................................... * Delete a PathName object. * * Input: *  path   PathName *  The object to be deleted. * Output: *  return PathName *  The deleted object (always NULL). */PathName *_del_PathName(PathName *path){  if(path) {    if(path->name)      free(path->name);    free(path);  };  return NULL;}/*....................................................................... * Return the pathname to a zero-length string. * * Input: *  path     PathName *  The pathname container. * Output: *  return       char *  The cleared pathname buffer, or NULL on error. */char *_pn_clear_path(PathName *path){/* * Check the arguments. */  if(!path) {    fprintf(stderr, "_pn_clear_path: NULL argument.\n");    return NULL;  };  path->name[0] = '\0';  return path->name;}/*....................................................................... * Append a string to a pathname, increasing the size of the pathname * buffer if needed. * * Input: *  path        PathName *  The pathname container. *  string    const char *  The string to be appended to the pathname. *                          Note that regardless of the slen argument, *                          this should be a '\0' terminated string. *  slen             int    The maximum number of characters to append *                          from string[], or -1 to append the whole *                          string. *  remove_escapes   int    If true, remove the backslashes that escape *                          spaces, tabs, backslashes etc.. * Output: *  return          char *  The pathname string path->name[], which may *                          have been reallocated, or NULL if there was *                          insufficient memory to extend the pathname. */char *_pn_append_to_path(PathName *path, const char *string, int slen,			int remove_escapes){  int pathlen;     /* The length of the pathname */  int i;/* * Check the arguments. */  if(!path || !string) {    fprintf(stderr, "_pn_append_to_path: NULL argument(s).\n");    return NULL;  };/* * Get the current length of the pathname. */  pathlen = strlen(path->name);/* * How many characters should be appended? */  if(slen < 0 || slen > strlen(string))    slen = strlen(string);/* * Resize the pathname if needed. */  if(!_pn_resize_path(path, pathlen + slen))    return NULL;/* * Append the string to the output pathname, removing any escape * characters found therein. */  if(remove_escapes) {    int is_escape = 0;    for(i=0; i<slen; i++) {      is_escape = !is_escape && string[i] == '\\';      if(!is_escape)	path->name[pathlen++] = string[i];    };/* * Terminate the string. */    path->name[pathlen] = '\0';  } else {/* * Append the string directly to the pathname. */    memcpy(path->name + pathlen, string, slen);    path->name[pathlen + slen] = '\0';  };  return path->name;}/*....................................................................... * Prepend a string to a pathname, increasing the size of the pathname * buffer if needed. * * Input: *  path        PathName *  The pathname container. *  string    const char *  The string to be prepended to the pathname. *                          Note that regardless of the slen argument, *                          this should be a '\0' terminated string. *  slen             int    The maximum number of characters to prepend *                          from string[], or -1 to append the whole *                          string. *  remove_escapes   int    If true, remove the backslashes that escape *                          spaces, tabs, backslashes etc.. * Output: *  return          char *  The pathname string path->name[], which may *                          have been reallocated, or NULL if there was *                          insufficient memory to extend the pathname. */char *_pn_prepend_to_path(PathName *path, const char *string, int slen,			  int remove_escapes){  int pathlen;     /* The length of the pathname */  int shift;       /* The number of characters to shift the suffix by */  int i,j;/* * Check the arguments. */  if(!path || !string) {    fprintf(stderr, "_pn_prepend_to_path: NULL argument(s).\n");    return NULL;  };/* * Get the current length of the pathname. */  pathlen = strlen(path->name);/* * How many characters should be appended? */  if(slen < 0 || slen > strlen(string))    slen = strlen(string);/* * Work out how far we need to shift the original path string to make * way for the new prefix. When removing escape characters, we need * final length of the new prefix, after unescaped backslashes have * been removed. */  if(remove_escapes) {    int is_escape = 0;    for(shift=0,i=0; i<slen; i++) {      is_escape = !is_escape && string[i] == '\\';      if(!is_escape)	shift++;    };  } else {    shift = slen;  };/* * Resize the pathname if needed. */  if(!_pn_resize_path(path, pathlen + shift))    return NULL;/* * Make room for the prefix at the beginning of the string. */  memmove(path->name + shift, path->name, pathlen+1);/* * Copy the new prefix into the vacated space at the beginning of the * output pathname, removing any escape characters if needed. */  if(remove_escapes) {    int is_escape = 0;    for(i=j=0; i<slen; i++) {      is_escape = !is_escape && string[i] == '\\';      if(!is_escape)	path->name[j++] = string[i];    };