pith/osdep/bldpath.c

   1 /*
   2  * ========================================================================
   3  * Copyright 2013-2022 Eduardo Chappa
   4  * Copyright 2006-2008 University of Washington
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * ========================================================================
  13  */
  14
  15 #include <system.h>
  16
  17 #if     STDC_HEADERS
  18 #include <ctype.h>
  19 #endif
  20
  21 #include "bldpath.h"
  22
  23 /*
  24  * Useful definitions
  25  */
  26 #ifdef  _WINDOWS
  27 #define ROOTED(S)       (*(S) == '\\' || (isalpha((unsigned char) (S)[0]) && (S)[1] == ':'))
  28 #define HOMERELATIVE(S) (FALSE)
  29 #else   /* UNIX */
  30 #define ROOTED(S)       (*(S) == '/')
  31 #define HOMERELATIVE(S) (*(S) == '~')
  32 #endif
  33
  34
  35
  36
  37 /*----------------------------------------------------------------------
  38       Paste together two pieces of a file name path
  39
  40   Args: pathbuf      -- Put the result here
  41         first_part   -- of path name
  42         second_part  -- of path name
  43         len          -- Length of pathbuf
  44
  45  Result: New path is in pathbuf.  Note that
  46          we don't have to check for /'s at end of first_part and beginning
  47          of second_part since multiple slashes are ok.
  48
  49 BUGS:  This is a first stab at dealing with fs naming dependencies, and others
  50 still exist.
  51   ----*/
  52 void
  53 build_path(char *pathbuf, char *first_part, char *second_part, size_t len)
  54 {
  55     if(!(pathbuf && len > 0))
  56       return;
  57
  58     pathbuf[0] = '\0';
  59
  60     if(!first_part || is_rooted_path(second_part)){
  61         if(second_part)
  62           strncpy(pathbuf, second_part, len-1);
  63
  64         pathbuf[len-1] = '\0';
  65     }
  66     else{
  67 #ifdef  _WINDOWS
  68         int i;
  69         char *orig_pathbuf = pathbuf;
  70
  71         for(i = 0; i < len-2 && first_part[i]; i++)
  72           *pathbuf++ = first_part[i];
  73
  74         if(second_part){
  75             if(i && first_part[i-1] == '\\'){   /* first part ended with \  */
  76                 if(*second_part == '\\')                /* and second starts with \ */
  77                   second_part++;                        /* else just append second  */
  78             }
  79             else if(*second_part != '\\')               /* no slash at all, so      */
  80               *pathbuf++ = '\\';                        /* insert one...            */
  81
  82             while(pathbuf-orig_pathbuf < len-1 && *second_part)
  83               *pathbuf++ = *second_part++;
  84         }
  85
  86         *pathbuf = '\0';
  87
  88 #else  /* UNIX */
  89
  90         size_t fpl = 0;
  91
  92         strncpy(pathbuf, first_part, len-2);
  93         pathbuf[len-2] = '\0';
  94         if(second_part){
  95             if(*pathbuf && pathbuf[(fpl=strlen(pathbuf))-1] != '/'){
  96                 pathbuf[fpl++] = '/';
  97                 pathbuf[fpl] = '\0';
  98             }
  99
 100             strncat(pathbuf, second_part, len-1-strlen(pathbuf));
 101         }
 102
 103         pathbuf[len-1] = '\0';
 104
 105 #endif
 106     }
 107 }
 108
 109
 110 /*----------------------------------------------------------------------
 111   Test to see if the given file path is absolute
 112
 113   Args: file -- file path to test
 114
 115  Result: TRUE if absolute, FALSE otw
 116
 117   ----*/
 118 int
 119 is_absolute_path(char *path)
 120 {
 121     return(path && (ROOTED(path) || HOMERELATIVE(path)));
 122 }
 123
 124
 125 /*
 126  * homedir_in_path - return pointer to point in path string where home dir
 127  *                   reference starts
 128  */
 129 int
 130 is_rooted_path(char *path)
 131 {
 132     return(path && ROOTED(path));
 133 }
 134
 135
 136 /*
 137  * homedir_in_path - return pointer to point in path string where home dir
 138  *                   reference starts
 139  */
 140 int
 141 is_homedir_path(char *path)
 142 {
 143     return(path && HOMERELATIVE(path));
 144 }
 145
 146
 147 /*
 148  * homedir_in_path - return pointer to point in path string where home dir
 149  *                   reference starts
 150  */
 151 char *
 152 homedir_in_path(char *path)
 153 {
 154 #ifdef  _WINDOWS
 155     return(NULL);
 156 #else   /* UNIX */
 157     char *p;
 158
 159     return((p = strchr(path, '~')) ? p : NULL);
 160 #endif
 161 }
 162
 163
 164 /*
 165  *
 166  */
 167 char *
 168 filename_parent_ref(char *s)
 169 {
 170 #ifdef  _WINDOWS
 171     return(strstr(s, "\\..\\"));
 172 #else   /* UNIX */
 173     return(strstr(s, "/../"));
 174 #endif
 175 }
 176
 177
 178 int
 179 filename_is_restricted(char *s)
 180 {
 181 #ifdef  _WINDOWS
 182     return(filename_parent_ref(s) != NULL);
 183 #else   /* UNIX */
 184     return(strchr("./~", s[0]) != NULL || filename_parent_ref(s) != NULL);
 185 #endif
 186 }