view lwar/replace.c @ 393:f2decd9b276d

Fix minor error in string parsing Growing a buffer by 32 bytes and then only saying the buffer grew by one byte is not exactly efficient. While not strictly broken, it's dumb. Fix it to actually count the 32 bytes.
author William Astle <lost@l-w.ca>
date Tue, 14 Jul 2015 23:12:24 -0600
parents 221b5f58d8ad
children 45df37e81741
line wrap: on
line source

/*
replace.c
Copyright © 2009 William Astle

This file is part of LWAR.

LWAR is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.

You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.

*/

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef _MSC_VER
#include <lw_win.h>	// windows build
#else
#include <unistd.h>
#endif

#include "lwar.h"

void do_replace(void)
{
	FILE *f;
	FILE *nf;
	unsigned char buf[8];
	long l;
	int c;
	FILE *f2;
	int i;
	char fnbuf[1024];
	char fnbuf2[1024];
		
	sprintf(fnbuf, "%s.tmp", archive_file);
	
	f = fopen(archive_file, "rb+");
	if (!f)
	{
		if (errno == ENOENT)
		{
			nf = fopen(fnbuf, "wb");
			if (nf)
			{
				fputs("LWAR1V", nf);
				goto doadd;
			}
		}
		perror("Cannot open archive file");
	}
	
	(void)(fread(buf, 1, 6, f) && 1);
	if (memcmp("LWAR1V", buf, 6))
	{
		fprintf(stderr, "%s is not a valid archive file.\n", archive_file);
		exit(1);
	}

	nf = fopen(fnbuf, "wb");
	if (!nf)
	{
		perror("Cannot create temp archive file");
		exit(1);
	}

	fputs("LWAR1V", nf);

	for (;;)
	{
		c = fgetc(f);
		if (c == EOF && ferror(f))
		{
			perror("Reading archive file");
			exit(1);
		}
		if (c == EOF)
			goto doadd;
		
		if (!c)
		{
			goto doadd;
		}
		
		// find the end of the file name
		i = 0;
		while (c)
		{
			fnbuf2[i++] = c;
			c = fgetc(f);
			if (c == EOF || ferror(f))
			{
				fprintf(stderr, "Bad archive file\n");
				exit(1);
			}
		}
		fnbuf2[i] = 0;
		
		// get length of archive member
		l = 0;
		c = fgetc(f);
		l = c << 24;
		c = fgetc(f);
		l |= c << 16;
		c = fgetc(f);
		l |= c << 8;
		c = fgetc(f);
		l |= c;
		
		// is it a file we are replacing? if so, do not copy it
		for (i = 0; i < nfiles; i++)
		{
			if (!strcmp(files[i], fnbuf2))
				break;
		}
		if (i < nfiles)
		{
			fseek(f, l, SEEK_CUR);
		}
		else
		{
			// otherwise, copy it
			fprintf(nf, "%s", fnbuf2);
			fputc(0, nf);
			fputc(l >> 24, nf);
			fputc((l >> 16) & 0xff, nf);
			fputc((l >> 8) & 0xff, nf);
			fputc(l & 0xff, nf);
			while (l)
			{
				c = fgetc(f);
				fputc(c, nf);
				l--;
			}
		}
	}
	
	// done with the original file
	fclose(f);
doadd:
	for (i = 0; i < nfiles; i++)
	{
		f2 = fopen(files[i], "rb");
		if (!f2)
		{
			fprintf(stderr, "Cannot open file %s:", files[i]);
			perror("");
			exit(1);
		}
		(void)(fread(buf, 1, 6, f2) && 1);
		if (mergeflag && !memcmp("LWAR1V", buf, 6))
		{
			// add archive contents...
			for (;;)
			{
				c = fgetc(f2);
				if (c == EOF || ferror(f2))
				{
					perror("Reading input archive file");
					exit(1);
				}
				if (c == EOF)
					break;
		
				if (!c)
				{
					break;
				}
		
				// find the end of the file name
				while (c)
				{
					fputc(c, nf);
					c = fgetc(f2);
					if (c == EOF || ferror(f))
					{
						fprintf(stderr, "Bad input archive file\n");
						exit(1);
					}
				}
				fputc(0, nf);
				
				// get length of archive member
				l = 0;
				c = fgetc(f2);
				fputc(c, nf);
				l = c << 24;
				c = fgetc(f2);
				fputc(c, nf);
				l |= c << 16;
				c = fgetc(f2);
				fputc(c, nf);
				l |= c << 8;
				c = fgetc(f2);
				fputc(c, nf);
				l |= c;
		
				while (l)
				{
					c = fgetc(f2);
					fputc(c, nf);
					l--;
				}
			}
			
			fclose(f2);
			continue;
		}
		fseek(f2, 0, SEEK_END);
		l = ftell(f2);
		fseek(f2, 0, SEEK_SET);
		fputs(files[i], nf);
		fputc(0, nf);
		fputc(l >> 24, nf);
		fputc((l >> 16) & 0xff, nf);
		fputc((l >> 8) & 0xff, nf);
		fputc(l & 0xff, nf);
		while (l)
		{
			c = fgetc(f2);
			fputc(c, nf);
			l--;
		}
	}
	
	// flag end of file
	fputc(0, nf);
	
	fclose(nf);
	
	if (rename(fnbuf, archive_file) < 0)
	{
		perror("Cannot replace old archive file");
		unlink(fnbuf);
	}
}