pith/tempfile.c

   1 /*
   2  * ========================================================================
   3  * Copyright 2006-2007 University of Washington
   4  * Copyright 2013-2022 Eduardo Chappa
   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 "../pith/headers.h"
  16 #include "../pith/tempfile.h"
  17
  18
  19 /*
  20  * Return the name of a file in the same directory as filename.
  21  * Same as temp_nam except it figures out a name in the same directory.
  22  * It also returns the name of the directory in ret_dir if ret_dir is
  23  * not NULL. That has to be freed by caller. If return is not NULL the
  24  * empty file has been created.
  25  */
  26 char *
  27 tempfile_in_same_dir(char *filename, char *prefix, char **ret_dir)
  28 {
  29 #ifndef MAXPATH
  30 #define MAXPATH 1000    /* Longest file path we can deal with */
  31 #endif
  32     char  dir[MAXPATH+1];
  33     char *dirp = NULL;
  34     char *ret_file = NULL;
  35
  36     if(filename){
  37         char *lc;
  38
  39         if((lc = last_cmpnt(filename)) != NULL){
  40             int to_copy;
  41
  42             to_copy = (lc - filename > 1) ? (lc - filename - 1) : 1;
  43             strncpy(dir, filename, MIN(to_copy, sizeof(dir)-1));
  44             dir[MIN(to_copy, sizeof(dir)-1)] = '\0';
  45         }
  46         else{
  47             dir[0] = '.';
  48             dir[1] = '\0';
  49         }
  50
  51         dirp = dir;
  52     }
  53
  54
  55     /* temp_nam creates ret_file */
  56     ret_file = temp_nam(dirp, prefix);
  57
  58     /*
  59      * If temp_nam can't write in dirp it puts the file in a temp directory
  60      * anyway. We don't want that to happen to us.
  61      */
  62     if(dirp && ret_file && !in_dir(dirp, ret_file)){
  63         our_unlink(ret_file);
  64         fs_give((void **)&ret_file);  /* sets it to NULL */
  65     }
  66
  67     if(ret_file && ret_dir && dirp)
  68       *ret_dir = cpystr(dirp);
  69
  70
  71     return(ret_file);
  72 }
  73
  74
  75 /*
  76  * Returns non-zero if dir is a prefix of path.
  77  *         zero     if dir is not a prefix of path, or if dir is empty.
  78  */
  79 int
  80 in_dir(char *dir, char *path)
  81 {
  82     return(*dir ? !strncmp(dir, path, strlen(dir)) : 0);
  83 }