.TH HISTORY 1
.SH NAME
history \- print file names from the dump
.SH SYNOPSIS
.B history
[
.B -Dabcemnw
] [
.B -fuv
] [
.B -d
.I dumpfilesystem
] [
.B -s
.I yyyymmdd
]
.I files ...
.SH DESCRIPTION
.I History
prints the names, dates, and sizes, and modifier of all versions of the named
.IR files ,
looking backwards in time,
stored in the dump file system.
If the file exists in the main tree, the first line of output will be its current state.
For example,
.IP
.EX
history /adm/users
.EE
.PP
produces
.IP
.EX
May 14 15:29:18 EDT 2001 /adm/users 10083 [adm]
May 14 15:29:18 EDT 2001 /n/dump/2001/0515/adm/users 10083 [adm]
May 11 17:26:24 EDT 2001 /n/dump/2001/0514/adm/users 10481 [adm]
May 10 16:40:51 EDT 2001 /n/dump/2001/0511/adm/users 10476 [adm]
	...
.EE
.PP
When presented with a path of the form
.BI /n/ fs / path \fR,
.I history
will use
.IB fs dump
as the name of the dump file system, and will print a history of
.IR path .
.PP
The
.B -v
option enables verbose debugging printout.
.PP
The 
.B -D
option causes
.IR diff (1)
to be run for each adjacent pair of dump files.
The options
.B -abcemnw
are passed through to
.IR diff;
the little-used
.I diff option
.B -f
is replaced by the functionality described below,
and the
.B -r
option is disallowed.
.PP
The
.B -u
option causes times to be printed in GMT (UT) rather than local time.
.PP
The
.B -d
option selects some other dump file system such as
.IR /n/bootesdump .
.PP
The
.B -f
option forces the search to continue even when the
file in question does not exist (useful for files that only
exist intermittently).
.PP
Finally, the
.B -s
option
sets the starting (most recent) date for the output.
.SH EXAMPLES
Check how often a user has been logged in.
.IP
.EX
history /usr/ches/tmp
.EE
.SH FILES
.B /n/dump
.SH SOURCE
.B /sys/src/cmd/history.c
.SH SEE ALSO
.IR fs (4)
.br
.IR yesterday (1)