積丹尼 Dan Jacobson wrote:
Well the archive created sure has a lot of their content. od -c will prove it to you.
No, the archive contains only metadata, not contents. For example: $ cd /proc/self $ tar -cf - limits | od -c 0000000 l i m i t s \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 0000020 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 * 0000140 \0 \0 \0 \0 0 0 0 0 4 4 4 \0 0 0 0 1 0000160 7 5 0 \0 0 0 0 1 7 5 0 \0 0 0 0 0 0000200 0 0 0 0 0 0 0 \0 1 3 0 0 7 5 1 3 0000220 3 1 2 \0 0 1 1 5 7 5 \0 0 \0 \0 \0 0000240 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 * 0000400 \0 u s t a r \0 e g g e r t \0 0000420 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 0000440 \0 \0 \0 \0 \0 \0 \0 \0 \0 e g g e r t \0 0000460 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 * 0024000 This contains metadata, which are something like this: $ stat limits File: 'limits' Size: 0 Blocks: 0 IO Block: 1024 regular empty file Device: 4h/4d Inode: 304543 Links: 1 Access: (0444/-r--r--r--) Uid: ( 1000/ eggert) Gid: ( 1000/ eggert) Access: 2016-11-05 19:34:50.841898208 -0700 Modify: 2016-11-05 19:34:50.841898208 -0700 Change: 2016-11-05 19:34:50.841898208 -0700 Birth: - It does not contain the contents, which are something like this: $ cat limits Limit Soft Limit Hard Limit Units Max cpu time unlimited unlimited seconds Max file size unlimited unlimited bytes Max data size unlimited unlimited bytes Max stack size 8720000 unlimited bytes Max core file size 0 unlimited bytes Max resident set unlimited unlimited bytes Max processes 59772 59772 processes Max open files 1024 65536 files Max locked memory 65536 65536 bytes Max address space unlimited unlimited bytes Max file locks unlimited unlimited locks Max pending signals 59772 59772 signals Max msgqueue size 819200 819200 bytes Max nice priority 0 0 Max realtime priority 0 0 Max realtime timeout unlimited unlimited us
