cpio文件系统的解压和制作方法

cpio解压方法：

    1.  # gunzip  XXX.cpio.gz

    2. cpio -idmv < XXX.cpio

制作cpio格式文件系统的方法：

    1. 执行gen_initramfs_list.sh脚本：

    #　gen_initramfs_list.sh ./Filesystem/ >filelist  

    其中 Filesystem文件夹是由上一步解压出来的cpio文件系统目录

    2. 执行gen_init_cpio产生cpio文件：

    # 　 gen_init_cpio filelist >rootfs.cpio

    ３.　压缩cpio生成cpio.gz文件：

    #  gzip rootfs.cpio

所使用文件说明：

gen_initramfs_list.sh：用于产生filelist

gen_init_cpio.c ：工具 gen_init_cpio的源码，编译后可以用

gen_init_cpio：用于产生cpio格式文件系统的可执行文件

gen_initramfs_list.sh的源码：

#!/bin/sh
# Copyright (C) Martin Schlemmer <[email protected]>
# Copyright (C) 2006 Sam Ravnborg <[email protected]>
#
# Released under the terms of the GNU GPL
#
# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
# the cpio archive, and then compresses it.
# The script may also be used to generate the inputfile used for gen_init_cpio
# This script assumes that gen_init_cpio is located in usr/ directory

# error out on errors
set -e

usage() {
cat << EOF
Usage:
$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
	-o <file>      Create compressed initramfs file named <file> using
		       gen_init_cpio and compressor depending on the extension
	-u <uid>       User ID to map to user ID 0 (root).
		       <uid> is only meaningful if <cpio_source> is a
		       directory.  "squash" forces all files to uid 0.
	-g <gid>       Group ID to map to group ID 0 (root).
		       <gid> is only meaningful if <cpio_source> is a
		       directory.  "squash" forces all files to gid 0.
	<cpio_source>  File list or directory for cpio archive.
		       If <cpio_source> is a .cpio file it will be used
		       as direct input to initramfs.
	-d             Output the default cpio list.

All options except -o and -l may be repeated and are interpreted
sequentially and immediately.  -u and -g states are preserved across
<cpio_source> options so an explicit "-u 0 -g 0" is required
to reset the root/group mapping.
EOF
}

# awk style field access
# $1 - field number; rest is argument string
field() {
	shift $1 ; echo $1
}

list_default_initramfs() {
	# echo usr/kinit/kinit
	:
}

default_initramfs() {
	cat <<-EOF >> ${output}
		# This is a very simple, default initramfs

		dir /dev 0755 0 0
		nod /dev/console 0600 0 0 c 5 1
		dir /root 0700 0 0
		# file /kinit usr/kinit/kinit 0755 0 0
		# slink /init kinit 0755 0 0
	EOF
}

filetype() {
	local argv1="$1"

	# symlink test must come before file test
	if [ -L "${argv1}" ]; then
		echo "slink"
	elif [ -f "${argv1}" ]; then
		echo "file"
	elif [ -d "${argv1}" ]; then
		echo "dir"
	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
		echo "nod"
	elif [ -p "${argv1}" ]; then
		echo "pipe"
	elif [ -S "${argv1}" ]; then
		echo "sock"
	else
		echo "invalid"
	fi
	return 0
}

list_print_mtime() {
	:
}

print_mtime() {
	local my_mtime="0"

	if [ -e "$1" ]; then
		my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
	fi

	echo "# Last modified: ${my_mtime}" >> ${output}
	echo "" >> ${output}
}

list_parse() {
	[ ! -L "$1" ] && echo "$1 \\" || :
}

# for each file print a line in following format
# <filetype> <name> <path to file> <octal mode> <uid> <gid>
# for links, devices etc the format differs. See gen_init_cpio for details
parse() {
	local location="$1"
	local name="/${location#${srcdir}}"
	# change '//' into '/'
	name=$(echo "$name" | sed -e 's://*:/:g')
	local mode="$2"
	local uid="$3"
	local gid="$4"
	local ftype=$(filetype "${location}")
	# remap uid/gid to 0 if necessary
	[ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
	[ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0
	local str="${mode} ${uid} ${gid}"

	[ "${ftype}" = "invalid" ] && return 0
	[ "${location}" = "${srcdir}" ] && return 0

	case "${ftype}" in
		"file")
			str="${ftype} ${name} ${location} ${str}"
			;;
		"nod")
			local dev=`LC_ALL=C ls -l "${location}"`
			local maj=`field 5 ${dev}`
			local min=`field 6 ${dev}`
			maj=${maj%,}

			[ -b "${location}" ] && dev="b" || dev="c"

			str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"
			;;
		"slink")
			local target=`readlink "${location}"`
			str="${ftype} ${name} ${target} ${str}"
			;;
		*)
			str="${ftype} ${name} ${str}"
			;;
	esac

	echo "${str}" >> ${output}

	return 0
}

unknown_option() {
	printf "ERROR: unknown option \"$arg\"\n" >&2
	printf "If the filename validly begins with '-', " >&2
	printf "then it must be prefixed\n" >&2
	printf "by './' so that it won't be interpreted as an option." >&2
	printf "\n" >&2
	usage >&2
	exit 1
}

list_header() {
	:
}

header() {
	printf "\n#####################\n# $1\n" >> ${output}
}

# process one directory (incl sub-directories)
dir_filelist() {
	${dep_list}header "$1"

	srcdir=$(echo "$1" | sed -e 's://*:/:g')
	dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n")

	# If $dirlist is only one line, then the directory is empty
	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
		${dep_list}print_mtime "$1"

		echo "${dirlist}" | \
		while read x; do
			${dep_list}parse ${x}
		done
	fi
}

# if only one file is specified and it is .cpio file then use it direct as fs
# if a directory is specified then add all files in given direcotry to fs
# if a regular file is specified assume it is in gen_initramfs format
input_file() {
	source="$1"
	if [ -f "$1" ]; then
		${dep_list}header "$1"
		is_cpio="$(echo "$1" | sed 's/^.*\.cpio\(\..*\)\?/cpio/')"
		if [ $2 -eq 0 -a ${is_cpio} = "cpio" ]; then
			cpio_file=$1
			echo "$1" | grep -q '^.*\.cpio\..*' && is_cpio_compressed="compressed"
			[ ! -z ${dep_list} ] && echo "$1"
			return 0
		fi
		if [ -z ${dep_list} ]; then
			print_mtime "$1" >> ${output}
			cat "$1"         >> ${output}
		else
		        echo "$1 \\"
			cat "$1" | while read type dir file perm ; do
				if [ "$type" = "file" ]; then
					echo "$file \\";
				fi
			done
		fi
	elif [ -d "$1" ]; then
		dir_filelist "$1"
	else
		echo "  ${prog}: Cannot open '$1'" >&2
		exit 1
	fi
}

prog=$0
root_uid=0
root_gid=0
dep_list=
cpio_file=
cpio_list=
output="/dev/stdout"
output_file=""
is_cpio_compressed=
compr="gzip -n -9 -f"

arg="$1"
case "$arg" in
	"-l")	# files included in initramfs - used by kbuild
		dep_list="list_"
		echo "deps_initramfs := $0 \\"
		shift
		;;
	"-o")	# generate compressed cpio image named $1
		shift
		output_file="$1"
		cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
		output=${cpio_list}
		echo "$output_file" | grep -q "\.gz$" && compr="gzip -n -9 -f"
		echo "$output_file" | grep -q "\.bz2$" && compr="bzip2 -9 -f"
		echo "$output_file" | grep -q "\.lzma$" && compr="lzma -9 -f"
		echo "$output_file" | grep -q "\.xz$" && \
				compr="xz --check=crc32 --lzma2=dict=1MiB"
		echo "$output_file" | grep -q "\.lzo$" && compr="lzop -9 -f"
		echo "$output_file" | grep -q "\.cpio$" && compr="cat"
		shift
		;;
esac
while [ $# -gt 0 ]; do
	arg="$1"
	shift
	case "$arg" in
		"-u")	# map $1 to uid=0 (root)
			root_uid="$1"
			shift
			;;
		"-g")	# map $1 to gid=0 (root)
			root_gid="$1"
			shift
			;;
		"-d")	# display default initramfs list
			default_list="$arg"
			${dep_list}default_initramfs
			;;
		"-h")
			usage
			exit 0
			;;
		*)
			case "$arg" in
				"-"*)
					unknown_option
					;;
				*)	# input file/dir - process it
					input_file "$arg" "$#"
					;;
			esac
			;;
	esac
done

# If output_file is set we will generate cpio archive and compress it
# we are careful to delete tmp files
if [ ! -z ${output_file} ]; then
	if [ -z ${cpio_file} ]; then
		timestamp=
		if test -n "$KBUILD_BUILD_TIMESTAMP"; then
			timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
			if test -n "$timestamp"; then
				timestamp="-t $timestamp"
			fi
		fi
		cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"
		usr/gen_init_cpio $timestamp ${cpio_list} > ${cpio_tfile}
	else
		cpio_tfile=${cpio_file}
	fi
	rm ${cpio_list}
	if [ "${is_cpio_compressed}" = "compressed" ]; then
		cat ${cpio_tfile} > ${output_file}
	else
		(cat ${cpio_tfile} | ${compr}  - > ${output_file}) \
		|| (rm -f ${output_file} ; false)
	fi
	[ -z ${cpio_file} ] && rm ${cpio_tfile}
fi
exit 0

gen_init_cpio.c的源码：

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <limits.h>

/*
 * Original work by Jeff Garzik
 *
 * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
 * Hard link support by Luciano Rocha
 */

#define xstr(s) #s
#define str(s) xstr(s)

static unsigned int offset;
static unsigned int ino = 721;
static time_t default_mtime;

struct file_handler {
	const char *type;
	int (*handler)(const char *line);
};

static void push_string(const char *name)
{
	unsigned int name_len = strlen(name) + 1;

	fputs(name, stdout);
	putchar(0);
	offset += name_len;
}

static void push_pad (void)
{
	while (offset & 3) {
		putchar(0);
		offset++;
	}
}

static void push_rest(const char *name)
{
	unsigned int name_len = strlen(name) + 1;
	unsigned int tmp_ofs;

	fputs(name, stdout);
	putchar(0);
	offset += name_len;

	tmp_ofs = name_len + 110;
	while (tmp_ofs & 3) {
		putchar(0);
		offset++;
		tmp_ofs++;
	}
}

static void push_hdr(const char *s)
{
	fputs(s, stdout);
	offset += 110;
}

static void cpio_trailer(void)
{
	char s[256];
	const char name[] = "TRAILER!!!";

	sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		"070701",		/* magic */
		0,			/* ino */
		0,			/* mode */
		(long) 0,		/* uid */
		(long) 0,		/* gid */
		1,			/* nlink */
		(long) 0,		/* mtime */
		0,			/* filesize */
		0,			/* major */
		0,			/* minor */
		0,			/* rmajor */
		0,			/* rminor */
		(unsigned)strlen(name)+1, /* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_rest(name);

	while (offset % 512) {
		putchar(0);
		offset++;
	}
}

static int cpio_mkslink(const char *name, const char *target,
			 unsigned int mode, uid_t uid, gid_t gid)
{
	char s[256];

	if (name[0] == '/')
		name++;
	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		"070701",		/* magic */
		ino++,			/* ino */
		S_IFLNK | mode,		/* mode */
		(long) uid,		/* uid */
		(long) gid,		/* gid */
		1,			/* nlink */
		(long) default_mtime,	/* mtime */
		(unsigned)strlen(target)+1, /* filesize */
		3,			/* major */
		1,			/* minor */
		0,			/* rmajor */
		0,			/* rminor */
		(unsigned)strlen(name) + 1,/* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_string(name);
	push_pad();
	push_string(target);
	push_pad();
	return 0;
}

static int cpio_mkslink_line(const char *line)
{
	char name[PATH_MAX + 1];
	char target[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	int rc = -1;

	if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
		fprintf(stderr, "Unrecognized dir format '%s'", line);
		goto fail;
	}
	rc = cpio_mkslink(name, target, mode, uid, gid);
 fail:
	return rc;
}

static int cpio_mkgeneric(const char *name, unsigned int mode,
		       uid_t uid, gid_t gid)
{
	char s[256];

	if (name[0] == '/')
		name++;
	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		"070701",		/* magic */
		ino++,			/* ino */
		mode,			/* mode */
		(long) uid,		/* uid */
		(long) gid,		/* gid */
		2,			/* nlink */
		(long) default_mtime,	/* mtime */
		0,			/* filesize */
		3,			/* major */
		1,			/* minor */
		0,			/* rmajor */
		0,			/* rminor */
		(unsigned)strlen(name) + 1,/* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_rest(name);
	return 0;
}

enum generic_types {
	GT_DIR,
	GT_PIPE,
	GT_SOCK
};

struct generic_type {
	const char *type;
	mode_t mode;
};

static struct generic_type generic_type_table[] = {
	[GT_DIR] = {
		.type = "dir",
		.mode = S_IFDIR
	},
	[GT_PIPE] = {
		.type = "pipe",
		.mode = S_IFIFO
	},
	[GT_SOCK] = {
		.type = "sock",
		.mode = S_IFSOCK
	}
};

static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
{
	char name[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	int rc = -1;

	if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
		fprintf(stderr, "Unrecognized %s format '%s'",
			line, generic_type_table[gt].type);
		goto fail;
	}
	mode |= generic_type_table[gt].mode;
	rc = cpio_mkgeneric(name, mode, uid, gid);
 fail:
	return rc;
}

static int cpio_mkdir_line(const char *line)
{
	return cpio_mkgeneric_line(line, GT_DIR);
}

static int cpio_mkpipe_line(const char *line)
{
	return cpio_mkgeneric_line(line, GT_PIPE);
}

static int cpio_mksock_line(const char *line)
{
	return cpio_mkgeneric_line(line, GT_SOCK);
}

static int cpio_mknod(const char *name, unsigned int mode,
		       uid_t uid, gid_t gid, char dev_type,
		       unsigned int maj, unsigned int min)
{
	char s[256];

	if (dev_type == 'b')
		mode |= S_IFBLK;
	else
		mode |= S_IFCHR;

	if (name[0] == '/')
		name++;
	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		"070701",		/* magic */
		ino++,			/* ino */
		mode,			/* mode */
		(long) uid,		/* uid */
		(long) gid,		/* gid */
		1,			/* nlink */
		(long) default_mtime,	/* mtime */
		0,			/* filesize */
		3,			/* major */
		1,			/* minor */
		maj,			/* rmajor */
		min,			/* rminor */
		(unsigned)strlen(name) + 1,/* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_rest(name);
	return 0;
}

static int cpio_mknod_line(const char *line)
{
	char name[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	char dev_type;
	unsigned int maj;
	unsigned int min;
	int rc = -1;

	if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
			 name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
		fprintf(stderr, "Unrecognized nod format '%s'", line);
		goto fail;
	}
	rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
 fail:
	return rc;
}

static int cpio_mkfile(const char *name, const char *location,
			unsigned int mode, uid_t uid, gid_t gid,
			unsigned int nlinks)
{
	char s[256];
	char *filebuf = NULL;
	struct stat buf;
	long size;
	int file = -1;
	int retval;
	int rc = -1;
	int namesize;
	int i;

	mode |= S_IFREG;

	file = open (location, O_RDONLY);
	if (file < 0) {
		fprintf (stderr, "File %s could not be opened for reading\n", location);
		goto error;
	}

	retval = fstat(file, &buf);
	if (retval) {
		fprintf(stderr, "File %s could not be stat()'ed\n", location);
		goto error;
	}

	filebuf = malloc(buf.st_size);
	if (!filebuf) {
		fprintf (stderr, "out of memory\n");
		goto error;
	}

	retval = read (file, filebuf, buf.st_size);
	if (retval < 0) {
		fprintf (stderr, "Can not read %s file\n", location);
		goto error;
	}

	size = 0;
	for (i = 1; i <= nlinks; i++) {
		/* data goes on last link */
		if (i == nlinks) size = buf.st_size;

		if (name[0] == '/')
			name++;
		namesize = strlen(name) + 1;
		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
		       "%08lX%08X%08X%08X%08X%08X%08X",
			"070701",		/* magic */
			ino,			/* ino */
			mode,			/* mode */
			(long) uid,		/* uid */
			(long) gid,		/* gid */
			nlinks,			/* nlink */
			(long) buf.st_mtime,	/* mtime */
			size,			/* filesize */
			3,			/* major */
			1,			/* minor */
			0,			/* rmajor */
			0,			/* rminor */
			namesize,		/* namesize */
			0);			/* chksum */
		push_hdr(s);
		push_string(name);
		push_pad();

		if (size) {
			if (fwrite(filebuf, size, 1, stdout) != 1) {
				fprintf(stderr, "writing filebuf failed\n");
				goto error;
			}
			offset += size;
			push_pad();
		}

		name += namesize;
	}
	ino++;
	rc = 0;
	
error:
	if (filebuf) free(filebuf);
	if (file >= 0) close(file);
	return rc;
}

static char *cpio_replace_env(char *new_location)
{
       char expanded[PATH_MAX + 1];
       char env_var[PATH_MAX + 1];
       char *start;
       char *end;

       for (start = NULL; (start = strstr(new_location, "${")); ) {
               end = strchr(start, '}');
               if (start < end) {
                       *env_var = *expanded = '\0';
                       strncat(env_var, start + 2, end - start - 2);
                       strncat(expanded, new_location, start - new_location);
                       strncat(expanded, getenv(env_var), PATH_MAX);
                       strncat(expanded, end + 1, PATH_MAX);
                       strncpy(new_location, expanded, PATH_MAX);
               } else
                       break;
       }

       return new_location;
}


static int cpio_mkfile_line(const char *line)
{
	char name[PATH_MAX + 1];
	char *dname = NULL; /* malloc'ed buffer for hard links */
	char location[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	int nlinks = 1;
	int end = 0, dname_len = 0;
	int rc = -1;

	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
				"s %o %d %d %n",
				name, location, &mode, &uid, &gid, &end)) {
		fprintf(stderr, "Unrecognized file format '%s'", line);
		goto fail;
	}
	if (end && isgraph(line[end])) {
		int len;
		int nend;

		dname = malloc(strlen(line));
		if (!dname) {
			fprintf (stderr, "out of memory (%d)\n", dname_len);
			goto fail;
		}

		dname_len = strlen(name) + 1;
		memcpy(dname, name, dname_len);

		do {
			nend = 0;
			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
					name, &nend) < 1)
				break;
			len = strlen(name) + 1;
			memcpy(dname + dname_len, name, len);
			dname_len += len;
			nlinks++;
			end += nend;
		} while (isgraph(line[end]));
	} else {
		dname = name;
	}
	rc = cpio_mkfile(dname, cpio_replace_env(location),
	                 mode, uid, gid, nlinks);
 fail:
	if (dname_len) free(dname);
	return rc;
}

static void usage(const char *prog)
{
	fprintf(stderr, "Usage:\n"
		"\t%s [-t <timestamp>] <cpio_list>\n"
		"\n"
		"<cpio_list> is a file containing newline separated entries that\n"
		"describe the files to be included in the initramfs archive:\n"
		"\n"
		"# a comment\n"
		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
		"dir <name> <mode> <uid> <gid>\n"
		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
		"slink <name> <target> <mode> <uid> <gid>\n"
		"pipe <name> <mode> <uid> <gid>\n"
		"sock <name> <mode> <uid> <gid>\n"
		"\n"
		"<name>       name of the file/dir/nod/etc in the archive\n"
		"<location>   location of the file in the current filesystem\n"
		"             expands shell variables quoted with ${}\n"
		"<target>     link target\n"
		"<mode>       mode/permissions of the file\n"
		"<uid>        user id (0=root)\n"
		"<gid>        group id (0=root)\n"
		"<dev_type>   device type (b=block, c=character)\n"
		"<maj>        major number of nod\n"
		"<min>        minor number of nod\n"
		"<hard links> space separated list of other links to file\n"
		"\n"
		"example:\n"
		"# A simple initramfs\n"
		"dir /dev 0755 0 0\n"
		"nod /dev/console 0600 0 0 c 5 1\n"
		"dir /root 0700 0 0\n"
		"dir /sbin 0755 0 0\n"
		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
		"\n"
		"<timestamp> is time in seconds since Epoch that will be used\n"
		"as mtime for symlinks, special files and directories. The default\n"
		"is to use the current time for these entries.\n",
		prog);
}

struct file_handler file_handler_table[] = {
	{
		.type    = "file",
		.handler = cpio_mkfile_line,
	}, {
		.type    = "nod",
		.handler = cpio_mknod_line,
	}, {
		.type    = "dir",
		.handler = cpio_mkdir_line,
	}, {
		.type    = "slink",
		.handler = cpio_mkslink_line,
	}, {
		.type    = "pipe",
		.handler = cpio_mkpipe_line,
	}, {
		.type    = "sock",
		.handler = cpio_mksock_line,
	}, {
		.type    = NULL,
		.handler = NULL,
	}
};

#define LINE_SIZE (2 * PATH_MAX + 50)

int main (int argc, char *argv[])
{
	FILE *cpio_list;
	char line[LINE_SIZE];
	char *args, *type;
	int ec = 0;
	int line_nr = 0;
	const char *filename;

	default_mtime = time(NULL);
	while (1) {
		int opt = getopt(argc, argv, "t:h");
		char *invalid;

		if (opt == -1)
			break;
		switch (opt) {
		case 't':
			default_mtime = strtol(optarg, &invalid, 10);
			if (!*optarg || *invalid) {
				fprintf(stderr, "Invalid timestamp: %s\n",
						optarg);
				usage(argv[0]);
				exit(1);
			}
			break;
		case 'h':
		case '?':
			usage(argv[0]);
			exit(opt == 'h' ? 0 : 1);
		}
	}

	if (argc - optind != 1) {
		usage(argv[0]);
		exit(1);
	}
	filename = argv[optind];
	if (!strcmp(filename, "-"))
		cpio_list = stdin;
	else if (!(cpio_list = fopen(filename, "r"))) {
		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
			filename, strerror(errno));
		usage(argv[0]);
		exit(1);
	}

	while (fgets(line, LINE_SIZE, cpio_list)) {
		int type_idx;
		size_t slen = strlen(line);

		line_nr++;

		if ('#' == *line) {
			/* comment - skip to next line */
			continue;
		}

		if (! (type = strtok(line, " \t"))) {
			fprintf(stderr,
				"ERROR: incorrect format, could not locate file type line %d: '%s'\n",
				line_nr, line);
			ec = -1;
			break;
		}

		if ('\n' == *type) {
			/* a blank line */
			continue;
		}

		if (slen == strlen(type)) {
			/* must be an empty line */
			continue;
		}

		if (! (args = strtok(NULL, "\n"))) {
			fprintf(stderr,
				"ERROR: incorrect format, newline required line %d: '%s'\n",
				line_nr, line);
			ec = -1;
		}

		for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
			int rc;
			if (! strcmp(line, file_handler_table[type_idx].type)) {
				if ((rc = file_handler_table[type_idx].handler(args))) {
					ec = rc;
					fprintf(stderr, " line %d\n", line_nr);
				}
				break;
			}
		}

		if (NULL == file_handler_table[type_idx].type) {
			fprintf(stderr, "unknown file type line %d: '%s'\n",
				line_nr, line);
		}
	}
	if (ec == 0)
		cpio_trailer();

	exit(ec);
}