1 #!/usr/local/plan9/bin/rc
2 
3 . 9.rc
4 
5 smon='s/Jan/01/
6 	s/Feb/02/
7 	s/Mar/03/
8 	s/Apr/04/
9 	s/May/05/
10 	s/Jun/06/
11 	s/Jul/07/
12 	s/Aug/08/
13 	s/Sep/09/
14 	s/Oct/10/
15 	s/Nov/11/
16 	s/Dec/12/'
17 
18 
19 fn usage {
20 	echo 'usage: yesterday [-cd] [-[[yy]yy]mm]dd] [-n daysago] file ...' >[1=2]
21 	exit 1
22 }
23 
24 fn Xcp {
25 	echo cp $1 $2
26 	cp $1 $2
27 }
28 
29 fn Xcarefulcp {
30 	if(! cmp -s $1 $2) Xcp $1 $2
31 }
32 
33 fn Xdiff {
34 	echo diff -c $1 $2
35 	diff -c $1 $2
36 }
37 
38 fn Xecho {
39 	echo $1
40 }
41 
42 year=`{date|sed 's/.* //'}
43 copy=Xecho
44 last=()
45 while(! ~ $#* 0 && ~ $1 -* && ! ~ $1 --){
46 	switch($1){
47 	case -c
48 		copy=Xcp
49 		shift
50 	case -d
51 		copy=Xdiff
52 		shift
53 	case -C
54 		copy=Xcarefulcp
55 		shift
56 	case -n*
57 		if(~ $1 -n){
58 			if(~ $#* 1)
59 				usage
60 			shift
61 			days=$1
62 		}
63 		if not
64 			days=`{echo $1 | sed 's/^-.//'}
65 		last=`{date `{hoc -e `{date -n} ^ '-'$days'*60*60*24'} | \
66 				sed -e 's%... (...) (..) ..:..:.. ... (....)%\3/\1\2%' -e 'y/ /0/' -e $smon}
67 		shift
68 	case -[0-9]
69 		mon=`{date|9 sed 's/^....(...).*/\1/' -e $smon}
70 		last=$year/$mon ^`{echo $1|sed 's/^-/0/'}
71 		shift
72 	case -[0-9][0-9]
73 		mon=`{date|9 sed 's/^....(...).*/\1/' -e $smon}
74 		last=$year/$mon ^`{echo $1|9 sed 's/^-//'}
75 		shift
76 	case -[0-9][0-9][0-9][0-9]
77 		last=$year/ ^ `{echo $1|9 sed 's/^-//'}
78 		shift
79 	case -[0-9][0-9][0-9][0-9][0-9][0-9]
80 		last=`{echo $year|9 sed 's/..$//'} ^ `{echo $1|9 sed 's/^-(..)/\1\//'}
81 		shift
82 	case -[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]
83 		last=`{echo $1|9 sed 's/^-(....)/\1\//'}
84 		shift
85 	case *
86 		usage
87 	}
88 }
89 if(! ~ $#* 0 && ~ $1 --)
90 	shift
91 
92 if(~ $#* 0)
93 	usage
94 
95 dir=`{pwd}
96 if(! ~ $status ''){
97 	echo 'yesterday: can''t find directory' >[1=2]
98 	exit 'pwd failed'
99 }
100 
101 h=`{hostname}
102 switch($h){
103 case amsterdam
104 	xdump=/dump/am
105 case *
106 	if(! test -d /dump/$h){
107 		echo 'no dumps on '^`{hostname} >[1=2]
108 		exit 1
109 	}
110 	xdump=/dump/$h
111 }
112 
113 for(i){
114 	xpath=$i
115 	if(! ~ $xpath /*)
116 		xpath=`{9 cleanname -d `{pwd} $i}
117 	dumppath=$xpath
118 	if(~ $#last 0)
119 		xlast=`{9 ls -t $xdump/$year|sed 1q}
120 	if not
121 		xlast=$xdump/$last
122 	$copy $xlast^$dumppath $xpath
123 }