From 6276da5abaede4ecc4bdc163f7781a586634c6fe Mon Sep 17 00:00:00 2001
From: Keith Bostic <bostic@ucbvax.Berkeley.EDU>
Date: Fri, 18 Jan 1991 02:23:32 -0800
Subject: [PATCH] date and time created 91/01/17 18:23:32 by bostic

SCCS-vsn: usr.bin/ar/archive.c 5.1
---
 usr/src/usr.bin/ar/archive.c | 133 +++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 usr/src/usr.bin/ar/archive.c

diff --git a/usr/src/usr.bin/ar/archive.c b/usr/src/usr.bin/ar/archive.c
new file mode 100644
index 0000000000..b446d1a0ac
--- /dev/null
+++ b/usr/src/usr.bin/ar/archive.c
@@ -0,0 +1,133 @@
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Hugh Smith at The University of Guelph.
+ *
+ * %sccs.include.redist.c%
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)archive.c	5.1 (Berkeley) %G%";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ar.h>
+#include "archive.h"
+
+extern char *archive;			/* archive name */
+
+open_archive(mode)
+	int mode;
+{
+	int created, fd, nr;
+	char buf[SARMAG];
+	
+	created = 0;
+	if (mode & O_CREAT) {
+		mode |= O_EXCL;
+		if ((fd = open(archive, mode, DEFFILEMODE)) >= 0) {
+			/* POSIX.2 puts create message on stderr. */
+			if (!(options & AR_C))
+				(void)fprintf(stderr,
+				    "ar: creating archive %s.\n", archive);
+			created = 1;
+			goto opened;
+		}
+		if (errno != EEXIST)
+			error(archive);
+		mode &= ~O_EXCL;
+	}
+	if ((fd = open(archive, mode, DEFFILEMODE)) < 0)
+		error(archive);
+
+	/* 
+	 * Attempt to place a lock on the opened file - if we get an 
+	 * error then someone is already working on this library.
+	 */
+opened:	if (flock(fd, LOCK_EX|LOCK_NB))
+		error(archive);
+	
+	/*
+	 * If not created, O_RDONLY|O_RDWR indicates that it has to be
+	 * in archive format.
+	 */
+	if (!created &&
+	    ((mode & O_ACCMODE) == O_RDONLY || (mode & O_ACCMODE) == O_RDWR)) {
+		if ((nr = read(fd, buf, SARMAG) != SARMAG)) {
+			if (nr >= 0)
+				badfmt();
+			error(archive);
+		} else if (bcmp(buf, ARMAG, SARMAG))
+			badfmt();
+	} else if (write(fd, ARMAG, SARMAG) != SARMAG)
+		error(archive);
+	return(fd);
+}
+
+close_archive(fd)
+	int fd;
+{
+	(void)flock(fd, LOCK_UN);
+	(void)close(fd);
+}
+
+/*
+ * copyfile --
+ *	Copy size bytes from one file to another - taking care to handle the
+ *	extra byte (for odd size files) when reading archives and tmpfiles
+ *	and writing an extra byte if necessary when adding files to archive.
+ *
+ *	The padding is really unnecessary, and is almost certainly a remnant
+ *	of early archive formats where the header included binary data which
+ *	a PDP-11 required to start on an even byte boundary.  It should have
+ *	been ripped out when the format changed.
+ */
+copyfile(cfp, size)
+	CF *cfp;
+	register off_t size;
+{
+	register int from, nr, nw, off, to;
+	char pad, buf[8*1024];
+	
+	if (!size)
+		return;
+
+	pad = size & 1;
+	from = cfp->rfd;
+	to = cfp->wfd;
+	while (size &&
+	    (nr = read(from, buf, MIN(size, sizeof(buf)))) > 0) {
+		size -= nr;
+		for (off = 0; off < nr; nr -= off, off += nw)
+			if ((nw = write(to, buf + off, nr)) < 0)
+				error(cfp->wname);
+	}
+	if (size) {
+		if (nr == 0)
+			badfmt();
+		error(cfp->rname);
+	}
+
+	if (pad) {
+		if (cfp->flags & RPAD && (nr = read(from, buf, 1)) != 1) {
+			if (nr == 0)
+				badfmt();
+			error(cfp->rname);
+		}
+		if (cfp->flags & WPAD) {
+			pad = '\n';
+			if (write(to, &pad, 1) != 1)
+				error(cfp->wname);
+		}
+	}
+}
-- 
2.20.1