--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwar/replace.c	Wed Jan 19 22:27:17 2011 -0700
@@ -0,0 +1,241 @@
+/*
+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>
+
+#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, "r+");
+	if (!f)
+	{
+		if (errno == ENOENT)
+		{
+			nf = fopen(fnbuf, "w");
+			if (nf)
+			{
+				fputs("LWAR1V", nf);
+				goto doadd;
+			}
+		}
+		perror("Cannot open archive file");
+	}
+	
+	fread(buf, 1, 6, f);
+	if (memcmp("LWAR1V", buf, 6))
+	{
+		fprintf(stderr, "%s is not a valid archive file.\n", archive_file);
+		exit(1);
+	}
+
+	nf = fopen(fnbuf, "w");
+	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], "r");
+		if (!f2)
+		{
+			fprintf(stderr, "Cannot open file %s:", files[i]);
+			perror("");
+			exit(1);
+		}
+		fread(buf, 1, 6, f2);
+		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);
+	}
+}