Move get_ar_headers to libbb, make dpkg_deb.c independent of ar.c

1 files changed, 118 insertions, 0 deletions

diff --git a/libbb/get_ar_headers.c b/libbb/get_ar_headers.c
new file mode 100644
index 0000000..cf7de5c
--- /dev/null
+++ b/libbb/get_ar_headers.c
@@ -0,0 +1,118 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) tons of folks.  Tracking down who wrote what
+ * isn't something I'm going to worry about...  If you wrote something
+ * here, please feel free to acknowledge your work.
+ *
+ * This program 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Based in part on code from sash, Copyright (c) 1999 by David I. Bell 
+ * Permission has been granted to redistribute this code under the GPL.
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "libbb.h"
+
+extern ar_headers_t get_ar_headers(int srcFd)
+{
+	typedef struct raw_ar_header_s {	/* Byte Offset */
+		char name[16];	/*  0-15 */
+		char date[12];	/* 16-27 */
+		char uid[6];	
+		char gid[6];	/* 28-39 */
+		char mode[8];	/* 40-47 */
+		char size[10];	/* 48-57 */
+		char fmag[2];	/* 58-59 */
+	} raw_ar_header_t;
+
+	raw_ar_header_t raw_ar_header;
+
+	ar_headers_t *head, *entry;
+	char ar_magic[8];
+	char *long_name=NULL;
+	
+	head = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+	entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+	
+	/* check ar magic */
+	if (full_read(srcFd, ar_magic, 8) != 8) {
+		error_msg_and_die("cannot read magic");
+	}
+
+	if (strncmp(ar_magic,"!<arch>",7) != 0) {
+		error_msg_and_die("invalid magic");
+	}
+
+	while (full_read(srcFd, (char *) &raw_ar_header, 60)==60) {
+		/* check the end of header markers are valid */
+		if ((raw_ar_header.fmag[0]!='`') || (raw_ar_header.fmag[1]!='\n')) {
+			char newline;
+			if (raw_ar_header.fmag[1]!='`') {
+				break;
+			}
+			/* some version of ar, have an extra '\n' after each entry */
+			read(srcFd, &newline, 1);
+			if (newline!='\n') {
+				break;
+			}
+			/* fix up the header, we started reading 1 byte too early due to a '\n' */
+			memmove((char *) &raw_ar_header, (char *)&raw_ar_header+1, 59);
+			/* dont worry about adding the last '\n', we dont need it now */
+		}
+		
+		entry->size = (off_t) atoi(raw_ar_header.size);
+		/* long filenames have '/' as the first character */
+		if (raw_ar_header.name[0] == '/') {
+			if (raw_ar_header.name[1] == '/') {
+				/* multiple long filenames are stored as data in one entry */
+				long_name = (char *) xrealloc(long_name, entry->size);
+				full_read(srcFd, long_name, entry->size);
+				continue;
+			}
+			else {
+				/* The number after the '/' indicates the offset in the ar data section
+					(saved in variable long_name) that conatains the real filename */
+				const int long_name_offset = (int) atoi((char *) &raw_ar_header.name[1]);
+				entry->name = xmalloc(strlen(&long_name[long_name_offset]));
+				strcpy(entry->name, &long_name[long_name_offset]);
+			}
+		}
+		else {
+			/* short filenames */
+			entry->name = xmalloc(16);
+			strncpy(entry->name, raw_ar_header.name, 16);
+		}
+		entry->name[strcspn(entry->name, " /")]='\0';
+
+		/* convert the rest of the now valid char header to its typed struct */	
+		parse_mode(raw_ar_header.mode, &entry->mode);
+		entry->mtime = atoi(raw_ar_header.date);
+		entry->uid = atoi(raw_ar_header.uid);
+		entry->gid = atoi(raw_ar_header.gid);
+		entry->offset = lseek(srcFd, 0, SEEK_CUR);
+
+		/* add this entries header to our combined list */
+		entry->next = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+		*entry->next = *head;
+		*head = *entry;
+		lseek(srcFd, (off_t) entry->size, SEEK_CUR);
+	}
+	return(*head);
+}
\ No newline at end of file