1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
#!/bin/sh
# update feeds, merge with old feeds.
# NOTE: assumes "sfeed_*" executables are in $PATH.
# defaults
sfeedpath="$HOME/.sfeed/feeds"
# used for processing feeds concurrently: wait until ${maxjobs} amount of
# feeds are finished at a time.
maxjobs=8
# load config (evaluate shellscript).
# loadconfig(configfile)
loadconfig() {
# allow to specify config via argv[1].
if [ "$1" != "" ]; then
# get absolute path of config file.
config=$(readlink -f "$1")
else
# default config location.
config="$HOME/.sfeed/sfeedrc"
fi
# config is loaded here to be able to override $sfeedpath or functions.
if [ -r "${config}" ]; then
. "${config}"
else
echo "Configuration file \"${config}\" does not exist or is not readable." >&2
echo "See sfeedrc.example for an example." >&2
exit 1
fi
}
# log(name,s)
log() {
printf '[%s] %-50.50s %s\n' "$(date +'%H:%M:%S')" "$1" "$2" >&2
}
# fetch a feed via HTTP/HTTPS etc.
# fetch(name, url, feedfile)
fetch() {
# fail on redirects,, hide User-Agent, timeout is 15 seconds,
# -z for If-Modified-Since.
curl -L --max-redirs 0 -H "User-Agent:" -f -s -m 15 \
-z "$3" "$2" 2>/dev/null
}
# convert encoding from one encoding to another.
# convertencoding(from, to)
convertencoding() {
if [ "$1" != "" ] && [ "$2" != "" ] && [ "$1" != "$2" ]; then
iconv -cs -f "$1" -t "$2" 2> /dev/null
else
# else no convert, just output
cat
fi
}
# filter fields.
# filter(name)
filter() {
cat
}
# order by timestamp (descending).
# order(name)
order() {
sort -t ' ' -k1rn,1
}
# merge raw files: unique sort by id, title, link.
# merge(name, oldfile, newfile)
merge() {
sort -t ' ' -u -k6,6 -k2,2 -k3,3 "$2" "$3" 2>/dev/null
}
# fetch and parse feed.
# feed(name, feedurl, [basesiteurl], [encoding])
feed() {
# wait until ${maxjobs} are finished: throughput using this logic is
# non-optimal, but it is simple and portable.
[ ${signo} -ne 0 ] && return
[ $((curjobs % maxjobs)) -eq 0 ] && wait
[ ${signo} -ne 0 ] && return
curjobs=$((curjobs + 1))
(name="$1"
filename="$(printf '%s' "$1" | tr '/' '_')"
feedurl="$2"
basesiteurl="$3"
encoding="$4"
sfeedfile="${sfeedpath}/${filename}"
tmpfeedfile="${sfeedtmpdir}/${filename}"
if ! fetch "${name}" "${feedurl}" "${sfeedfile}" > "${tmpfeedfile}.fetch"; then
log "${name}" "FAIL (FETCH)"
return
fi
# try to detect encoding (if not specified). if detecting the encoding fails assume utf-8.
[ "${encoding}" = "" ] && encoding=$(sfeed_xmlenc < "${tmpfeedfile}.fetch")
if ! convertencoding "${encoding}" "utf-8" < "${tmpfeedfile}.fetch" > "${tmpfeedfile}.utf8"; then
log "${name}" "FAIL (ENCODING)"
return
fi
rm -f "${tmpfeedfile}.fetch"
if ! sfeed "${basesiteurl}" < "${tmpfeedfile}.utf8" > "${tmpfeedfile}.tsv"; then
log "${name}" "FAIL (CONVERT)"
return
fi
rm -f "${tmpfeedfile}.enc"
if ! filter "${name}" < "${tmpfeedfile}.tsv" > "${tmpfeedfile}.filter"; then
log "${name}" "FAIL (FILTER)"
return
fi
rm -f "${tmpfeedfile}.tsv"
# new feed data is empty: no need for below stages.
if [ ! -s "${tmpfeedfile}.filter" ]; then
log "${name}" "OK"
return
fi
# if file does not exist yet "merge" with /dev/null.
if [ -e "${sfeedfile}" ]; then
oldfile="${sfeedfile}"
else
oldfile="/dev/null"
fi
if ! merge "${name}" "${oldfile}" "${tmpfeedfile}.filter" > "${tmpfeedfile}.merge"; then
log "${name}" "FAIL (MERGE)"
return
fi
rm -f "${tmpfeedfile}.filter"
if ! order "${name}" < "${tmpfeedfile}.merge" > "${tmpfeedfile}.order"; then
log "${name}" "FAIL (ORDER)"
return
fi
rm -f "${tmpfeedfile}.merge"
# atomic move.
if ! mv "${tmpfeedfile}.order" "${sfeedfile}"; then
log "${name}" "FAIL (MOVE)"
return
fi
# OK
log "${name}" "OK"
) &
}
cleanup() {
# remove temporary directory with feed files.
rm -rf "${sfeedtmpdir}"
}
sighandler() {
signo="$1"
# ignore TERM signal for myself.
trap -- "" TERM
# kill all running childs >:D
kill -TERM -$$
}
feeds() {
echo "Configuration file \"${config}\" is invalid or does not contain a \"feeds\" function." >&2
echo "See sfeedrc.example for an example." >&2
}
# job counter.
curjobs=0
# signal number received for parent.
signo=0
# SIGINT: signal to interrupt parent.
trap -- "sighandler 2" "INT"
# SIGTERM: signal to terminate parent.
trap -- "sighandler 15" "TERM"
# load config file.
loadconfig "$1"
# fetch feeds and store in temporary directory.
sfeedtmpdir="$(mktemp -d '/tmp/sfeed_XXXXXX')"
# make sure path exists.
mkdir -p "${sfeedpath}"
# fetch feeds specified in config file.
feeds
# wait till all feeds are fetched (concurrently).
[ ${signo} -eq 0 ] && wait
# cleanup temporary files etc.
cleanup
# on signal SIGINT and SIGTERM exit with signal number + 128.
[ ${signo} -ne 0 ] && exit $((signo+128))
exit 0
|
