yesterday(1) [plan9 man page]
YESTERDAY(1) General Commands Manual YESTERDAY(1) NAME
yesterday - print file names from the dump SYNOPSIS
yesterday [ -c ] [ -date ] files ... DESCRIPTION
Yesterday prints the names of the files from the most recent dump. Since dumps are done early in the morning, yesterday's files are really in today's dump. For example, if today is March 17, 1992, yesterday /adm/users prints /n/dump/1992/0317/adm/users In fact, the implementation is to select the most recent dump in the current year, so the dump selected may not be from today. With option -c, yesterday copies the dump file to the current directory. The date option selects other day's dumps, with a format of 2, 4, 6, or 8 digits of the form dd, mmdd, yymmdd, or yyyymmdd. Yesterday does not guarantee that the string it prints represents an existing file. EXAMPLES
Back up to yesterday's MIPS binary of vc: cd /mips/bin yesterday -c vc Temporarily back up to March 1's MIPS C library to see if a program runs correctly when loaded with it: bind `{yesterday -0301 /mips/lib/libc.a} /mips/lib/libc.a rm v.out mk v.out FILES
/n/dump SOURCE
/rc/bin/yesterday SEE ALSO
fs(4) BUGS
It's hard to use this command without singing. YESTERDAY(1)
Check Out this Related Man Page
FS(4) Kernel Interfaces Manual FS(4) NAME
fs - file server, dump SYNOPSIS
none DESCRIPTION
The file server is the main file system for Plan 9. It is a stand-alone system that runs on a separate computer. It serves the Plan 9 protocol on a variety of networks including Datakit/URP, Ethernet IL/IP and Cyclone fiber direct connections. The name of the main file server at Murray Hill is bootes. The file server normally requires all users except to provide authentication tickets on each attach(5). This can be disabled using the noauth configuration command (see fsconfig(8)). The user none is always allowed to attach to bootes without authentication but has minimal permissions. Bootes maintains three file systems on a combination of disks and write-once-read-many (WORM) magneto-optical disks. other is a simple disk-based file system similar to kfs(4). main is a worm-based file system with a disk-based look-aside cache. The disk cache holds modified worm blocks to overcome the write- once property of the worm. The cache also holds recently accessed non-modified blocks to speed up the effective access time of the worm. Occasionally (usually daily at 5AM) the modified blocks in the disk cache are dumped. At this time, traffic to the file sys- tem is halted and the modified blocks are relabeled to the unwritten portion of the worm. After the dump, the file system traffic is continued and the relabeled blocks are copied to the worm by a background process. dump Each time the main file system is dumped, its root is appended to a subdirectory of the dump file system. Since the dump file sys- tem is not mirrored with a disk cache, it is read-only. The name of the newly added root is created from the date of the dump: /yyyy/mmdds. Here yyyy is the full year, mm is the month number, dd is the day number and s is a sequence number if more than one dump is done in a day. For the first dump, s is null. For the subsequent dumps s is 1, 2, 3, etc. The root of the main file system that is frozen on the first dump of March 1, 1992 will be named /1992/0301/ in the dump file sys- tem. EXAMPLES
Place the root of the dump file system on /n/dump and show the modified times of the MIPS C compiler over all dumps in February, 1992: 9fs dump ls -l /n/dump/1992/02??/mips/bin/vc To get only one line of output for each version of the compiler: ls -lp /n/dump/1992/02??/mips/bin/vc | uniq Make the other file system available in directory /n/bootesother: mount -c /srv/boot /n/bootesother other SOURCE
/sys/src/fs SEE ALSO
yesterday(1), srv(4), fs(8) Sean Quinlan, ``A Cached WORM File System'', Software - Practice and Experience, December, 1991 FS(4)