date and time created 91/01/17 18:23:32 by bostic

SCCS-vsn: usr.bin/ar/archive.c 5.1

diff --git a/usr/src/usr.bin/ar/archive.c b/usr/src/usr.bin/ar/archive.c
new file mode 100644 (file)
index 0000000..b446d1a
--- /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);
+               }
+       }
+}