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//******************************************************************************
// Copyright 1999-2002,2021 by Thomas E. Dickey *
// All Rights Reserved. *
// *
// Permission to use, copy, modify, and distribute this software and its *
// documentation for any purpose and without fee is hereby granted, provided *
// that the above copyright notice appear in all copies and that both that *
// copyright notice and this permission notice appear in supporting *
// documentation, and that the name of the above listed copyright holder(s) *
// not be used in advertising or publicity pertaining to distribution of the *
// software without specific, written prior permission. THE ABOVE LISTED *
// COPYRIGHT HOLDER(S) DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, *
// INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO *
// EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR 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. *
//******************************************************************************
// $Id: backup.cpp,v 1.11 2021/01/08 23:31:06 tom Exp $
#include "bcpp.h"
#include <string.h>
inline const char *endOf(const char *s)
{
return (s + strlen(s));
}
inline char *endOf(char *s)
{
return (s + strlen(s));
}
inline bool isPathDelim(char ch)
{
return ((ch == '\\') || (ch == '/'));
}
static char *FileSuffix(char *name)
{
char * suffix = endOf(name);
while ( ((*suffix != '.') && (suffix > name)) && !isPathDelim(*suffix) )
suffix--;
if ((suffix <= name) || isPathDelim(*suffix))
suffix = endOf(name);
return suffix;
}
// Function creates a backup of oldFilename, by renaming it to either
// a ".orig" or ".bac" extension. Thereafter, the program will read
// from the backup file, and write to the orignal filename.
//
int BackupFile (char*& oldFilename, char*& newFilename)
{
const char* suffix = ".bac";
newFilename = oldFilename;
oldFilename = new char[strlen(newFilename)+6];
if (oldFilename == NULL)
return -1;
strcpy(oldFilename, newFilename);
char * pLook = FileSuffix(oldFilename);
strcat(oldFilename, ".orig");
if (rename(newFilename, oldFilename) != 0)
{
FILE *fp = fopen(oldFilename, "r");
if (fp != 0)
{
warning("backup already exists: %s\n", oldFilename);
fclose(fp);
return -1;
}
strcpy (pLook, suffix);
if (rename(newFilename, oldFilename) != 0)
{
warning("cannot rename %s\n", newFilename);
return -1;
}
}
return 0;
}
void RestoreIfUnchanged(char *oldFilename, char *newFilename)
{
FILE *newFp = fopen(newFilename, "r");
FILE *oldFp = fopen(oldFilename, "r");
bool changed = false;
int newCh = EOF;
int oldCh = EOF;
if (newFp != 0
&& oldFp != 0)
{
do
{
newCh = fgetc(newFp);
oldCh = fgetc(oldFp);
if (newCh != oldCh)
break;
}
while (newCh != EOF
&& oldCh != EOF);
changed = (newCh != oldCh);
}
if (newFp != 0)
fclose(newFp);
if (oldFp != 0)
fclose(oldFp);
if (!changed)
{
if (remove(newFilename) != 0)
warning("cannot remove %s\n", newFilename);
else if (rename(oldFilename, newFilename) != 0)
warning("cannot rename %s\n", oldFilename);
}
}
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