yesterday, diffy - print file names from the dump
SYNOPSISyesterday [ -abcCdDs ] [ -n daysago ] [ -date ] files ...
diffy [ -abcefmnrw ] files ...
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,
In fact, the implementation is to select the most recent dump in the
current year, so the dump selected may not be from today.
When presented with a path of the form /n/fs/path, yesterday will look
for dump files of the form /n/fsdump/yyyy/hhmm/path.
By default, yesterday prints the names of the dump files corresponding
to the named files. The first set of options changes this behavior.
-a Run acme(1)'s adiff to compare the dump files with the named
-b Bind the dump files over the named files.
-c Copy the dump files over the named files.
-C Copy the dump files over the named files only when they differ.
-d Run diff to compare the dump files with the named files.
-D Run diff -n to compare the dump files with the named files.
The date option selects other day's dumps, with a format of 1, 2, 4, 6,
or 8 digits of the form d, dd, mmdd, yymmdd, or yyyymmdd.
The -n option selects the dump daysago prior to the current day.
The -s option selects the most recent snapshot instead of the most
recent archived dump. Snapshots may occur more frequently than dumps.
Yesterday does not guarantee that the string it prints represents an
Diffy runs diff(1) with the given options to compare yesterday's ver‐
sion of each of the named files with today's.
Back up to yesterday's MIPS binary of vc:
Temporarily back up to March 1's MIPS C library to see if a program
runs correctly when loaded with it:
yesterday-b -0301 /mips/lib/libc.a
Find what has changed in the C library since March 1:
yesterday-d -0301 /sys/src/libc/port/*.c
Find what has changed in the source tree today:
diffy -r /sys/src
SEE ALSOhistory(1), bind(1), diff(1), fs(4).
It's hard to use this command without singing.