view lwar/extract.c @ 374:8e25147c2aa8

Clean up various "externs" Apparently some compilers seriously choke on the "extern" keyword in some circumstances where GCC does not. Remove most instances of "extern" to guard against that. Thanks to Erik G <erik@6809.org> for the patch.
author William Astle <lost@l-w.ca>
date Mon, 13 Jul 2015 20:31:56 -0600
parents 6f4c4d59666f
children 45df37e81741
line wrap: on
line source

/*
extract.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>

#include "lwar.h"

void do_extract(void)
{
	FILE *f;
	char buf[8];
	long l;
	int c;
	char fnbuf[1024];
	int i;
	FILE *nf;
	
	f = fopen(archive_file, "rb");
	if (!f)
	{
		perror("Opening archive file");
		exit(1);
	}
	
	(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);
	}

	for (;;)
	{
		c = fgetc(f);
		if (ferror(f))
		{
			perror("Reading archive file");
			exit(1);
		}
		if (c == EOF)
			return;
		
		
		// find the end of the file name
		if (!c)
			return;
		
		i = 0;
		while (c)
		{
			fnbuf[i++] = c;
			c = fgetc(f);
			if (c == EOF || ferror(f))
			{
				fprintf(stderr, "Bad archive file\n");
				exit(1);
			}
		}
		fnbuf[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;
		
		for (i = 0; i < nfiles; i++)
		{
			if (!strcmp(files[i], fnbuf))
				break;
		}
		if (i < nfiles || nfiles == 0)
		{
			// extract the file
			nf = fopen(fnbuf, "wb");
			if (!nf)
			{
				fprintf(stderr, "Cannot extract '%s': %s\n", fnbuf, strerror(errno));
				exit(1);
			}
			while (l)
			{
				c = fgetc(f);
				fputc(c, nf);
				l--;
			}
			fclose(nf);
		}
		else
		{
			// skip the file
			fseek(f, l, SEEK_CUR);
		}
	}
}