cpio命令详解（3）

4. cpio命令实例

（1）基础类命令

cpio {-?|--help|--usage|--version}

1）提供简短帮助摘要并退出

命令为：

bash 复制代码

cpio -?
或
cpio --help

实际命令及结果如下：

bash 复制代码

$ cpio -?
Usage: cpio [OPTION...] [destination-directory]
GNU `cpio' copies files to and from archives

Examples:
  # Copy files named in name-list to the archive
  cpio -o < name-list [> archive]
  # Extract files from the archive
  cpio -i [< archive]
  # Copy files named in name-list to destination-directory
  cpio -p destination-directory < name-list

 Main operation mode:
  -i, --extract              Extract files from an archive (run in copy-in
                             mode)
  -o, --create               Create the archive (run in copy-out mode)
  -p, --pass-through         Run in copy-pass mode
  -t, --list                 Print a table of contents of the input

 Operation modifiers valid in any mode:

      --block-size=BLOCK-SIZE   Set the I/O block size to BLOCK-SIZE * 512
                             bytes
  -B                         Set the I/O block size to 5120 bytes
  -c                         Use the old portable (ASCII) archive format
  -C, --io-size=NUMBER       Set the I/O block size to the given NUMBER of
                             bytes
  -D, --directory=DIR        Change to directory DIR
      --force-local          Archive file is local, even if its name contains
                             colons
  -H, --format=FORMAT        Use given archive FORMAT
      --quiet                Do not print the number of blocks copied
  -R, --owner=[USER][:.][GROUP]   Set the ownership of all files created to the
                             specified USER and/or GROUP
  -v, --verbose              Verbosely list the files processed
  -V, --dot                  Print a "." for each file processed
  -W, --warning=FLAG         Control warning display. Currently FLAG is one of
                             'none', 'truncate', 'all'. Multiple options
                             accumulate.

 Operation modifiers valid in copy-in and copy-out modes

  -F, --file=[[USER@]HOST:]FILE-NAME
                             Use this FILE-NAME instead of standard input or
                             output. Optional USER and HOST specify the user
                             and host names in case of a remote archive
  -M, --message=STRING       Print STRING when the end of a volume of the
                             backup media is reached
      --rsh-command=COMMAND  Use COMMAND instead of rsh

 Operation modifiers valid only in copy-in mode:

  -b, --swap                 Swap both halfwords of words and bytes of
                             halfwords in the data. Equivalent to -sS
  -f, --nonmatching          Only copy files that do not match any of the given
                             patterns
  -I [[USER@]HOST:]FILE-NAME Archive filename to use instead of standard input.
                             Optional USER and HOST specify the user and host
                             names in case of a remote archive
  -n, --numeric-uid-gid      In the verbose table of contents listing, show
                             numeric UID and GID
  -r, --rename               Interactively rename files
  -s, --swap-bytes           Swap the bytes of each halfword in the files
  -S, --swap-halfwords       Swap the halfwords of each word (4 bytes) in the
                             files
      --to-stdout            Extract files to standard output

  -E, --pattern-file=FILE    Read additional patterns specifying filenames to
                             extract or list from FILE
      --only-verify-crc      When reading a CRC format archive, only verify the
                             CRC's of each file in the archive, don't actually
                             extract the files

 Operation modifiers valid only in copy-out mode:

  -A, --append               Append to an existing archive.
      --device-independent, --reproducible
                             Create device-independent (reproducible) archives
      --ignore-devno         Don't store device numbers
  -O [[USER@]HOST:]FILE-NAME Archive filename to use instead of standard
                             output. Optional USER and HOST specify the user
                             and host names in case of a remote archive
      --renumber-inodes      Renumber inodes

 Operation modifiers valid only in copy-pass mode:

  -l, --link                 Link files instead of copying them, when
                             possible

 Operation modifiers valid in copy-in and copy-out modes:

      --absolute-filenames   Do not strip file system prefix components from
                             the file names
      --no-absolute-filenames   Create all files relative to the current
                             directory

 Operation modifiers valid in copy-out and copy-pass modes:

  -0, --null                 Filenames in the list are delimited by null
                             characters instead of newlines
  -a, --reset-access-time    Reset the access times of files after reading
                             them
  -L, --dereference          Dereference  symbolic  links  (copy  the files
                             that they point to instead of copying the links).

 Operation modifiers valid in copy-in and copy-pass modes:

  -d, --make-directories     Create leading directories where needed
  -m, --preserve-modification-time
                             Retain previous file modification times when
                             creating files
      --no-preserve-owner    Do not change the ownership of the files
      --sparse               Write files with large blocks of zeros as sparse
                             files
  -u, --unconditional        Replace all files unconditionally

  -?, --help                 give this help list
      --usage                give a short usage message
      --version              print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.

Report bugs to <bug-cpio@gnu.org>.

cpio --help命令也是同样结果。

2）打印一条简短的使用说明并退出

命令为：

bash 复制代码

cpio --usage

实际命令及结果如下：

bash 复制代码

$ cpio --usage
Usage: cpio [-ioptBcvVbfnrsSAl0aLdmu?] [-C NUMBER] [-D DIR] [-H FORMAT]
            [-R [USER][:.][GROUP]] [-W FLAG] [-F [[USER@]HOST:]FILE-NAME]
            [-M STRING] [-I [[USER@]HOST:]FILE-NAME] [-E FILE]
            [-O [[USER@]HOST:]FILE-NAME] [--extract] [--create]
            [--pass-through] [--list] [--block-size=BLOCK-SIZE]
            [--io-size=NUMBER] [--directory=DIR] [--force-local]
            [--format=FORMAT] [--quiet] [--owner=[USER][:.][GROUP]] [--verbose]
            [--dot] [--warning=FLAG] [--file=[[USER@]HOST:]FILE-NAME]
            [--message=STRING] [--rsh-command=COMMAND] [--swap] [--nonmatching]
            [--numeric-uid-gid] [--rename] [--swap-bytes] [--swap-halfwords]
            [--to-stdout] [--pattern-file=FILE] [--only-verify-crc] [--append]
            [--device-independent] [--reproducible] [--ignore-devno]
            [--renumber-inodes] [--link] [--absolute-filenames]
            [--no-absolute-filenames] [--null] [--reset-access-time]
            [--dereference] [--make-directories] [--preserve-modification-time]
            [--no-preserve-owner] [--sparse] [--unconditional] [--help]

3）打印程序版本号并退出

命令为：

bash 复制代码

cpio --version

实际命令及结果如下：

bash 复制代码

$ cpio --version
cpio (GNU cpio) 2.13
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Phil Nelson, David MacKenzie, John Oleynick,
and Sergey Poznyakoff.

（2）打包（Copy-out）类命令

准备工作：创建实验文件夹及其下文件：

bash 复制代码

$ cd cpio_test/
habit@ubuntu:~/work/shiyans/cpio_test$ mkdir bin conf etc lib
habit@ubuntu:~/work/shiyans/cpio_test$ touch etc/test.txt
habit@ubuntu:~/work/shiyans/cpio_test$ 
habit@ubuntu:~/work/shiyans/cpio_test$ tree
.
├── bin
├── conf
├── etc
│   └── test.txt
└── lib

4 directories, 1 file
habit@ubuntu:~/work/shiyans/cpio_test$

bash 复制代码

$ cat init
#!/bin/bash

1）基础打包（当前目录）

命令为：

bash 复制代码

ls | cpio -ov > backup.cpio          # 仅文件（不含子目录）
find . -depth | cpio -ov > all.cpio   # 递归全目录（推荐）

实际命令及结果如下：

bash 复制代码

$ ls | cpio -ov > backup.cpio
backup.cpio
bin
conf
etc
init
lib
1 block

bash 复制代码

$ find . -depth | cpio -ov > all.cpio
./all.cpio
./backup.cpio
./init
./etc/test.txt
./etc
./bin
./conf
./lib
.
2 blocks

涉及参数：

-o或--create：执行copy-out模式，建立备份档。

-v或--verbose：详细显示指令的执行过程。

如果不加-v参数，则实际结果为：

bash 复制代码

$ ls | cpio -o > backup.cpio
1 block
$ find . -depth | cpio -o > all.cpio
2 blocks

2）安全打包（含空格）

命令为：

bash 复制代码

find . -print0 | cpio -0ov > safe.cpio  # -print0 + -0 防空格/特殊字符

实际命令及结果如下：

bash 复制代码

$ find . -print0 | cpio -0ov > safe.cpio
.
./init
./etc
./etc/test.txt
./bin
./conf
./safe.cpio
./lib
1 block
$ ls
bin  conf  etc  init  lib  safe.cpio

涉及参数：

-0或--null：接受新增列控制字符，通常配合find指令的"-print0"参数使用。

分解动作：

bash 复制代码

$ find . -print0
../init./etc./etc/test.txt./bin./conf./lib$

3）initramfs 专用（强制newc）

命令为：

bash 复制代码

find . | cpio -ov -H newc > initramfs.cpio  # 内核initrd标准格式

实际命令及结果如下：

bash 复制代码

$ find . | cpio -ov -H newc > initramfs.cpio
.
./init
./etc
./etc/test.txt
cpio: File ./initramfs.cpio grew, 512 new bytes not copied
./initramfs.cpio
./bin
./conf
./lib
3 blocks

涉及参数：

-H <备份格式>：指定备份时欲使用的文件格式（new/crc/tar/ustar）。

-H参数详细说明：

指定格式，initramfs/initrd必须用newc：

bin：旧二进制（废弃）
odc：旧ASCII
newc ：SVR4便携格式（initramfs专用）
crc：带校验（newc + CRC）
tar/ustar：兼容tar

find命令带/不带-print0的区别如下：

bash 复制代码

$ find .
.
./init
./etc
./etc/test.txt
./bin
./conf
./lib

bash 复制代码

$ find . -print0
../init./etc./etc/test.txt./bin./conf./lib$

4）指定文件/排除

命令为：

bash 复制代码

find . -name "*.c" | cpio -ov > src.cpio        # 仅C文件
find . -path "./tmp" -prune -o -print | cpio -ov > no_tmp.cpio  # 排除tmp

在原有测试文件夹下添加test.c以及tmp文件夹：

bash 复制代码

$ ls
bin  conf  etc  init  lib
$ touch test.c
$ mkdir tmp
$ ls
bin  conf  etc  init  lib  test.c  tmp
$ tree
.
├── bin
├── conf
├── etc
│   └── test.txt
├── init
├── lib
├── test.c
└── tmp

5 directories, 3 files

实际命令及结果如下：

bash 复制代码

$ find . -name "*.c" | cpio -ov > src.cpio
./test.c
1 block

bash 复制代码

$ find . -path "./tmp" -prune -o -print | cpio -ov > no_tmp.cpio
.
./init
./etc
./etc/test.txt
./no_tmp.cpio
./bin
./conf
./test.c
./lib
1 block

更多内容请看下回。