summaryrefslogtreecommitdiff
path: root/sfeed_update
blob: cf384d10fadc205a686f55f31826ee491e5ff611 (plain)
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
#!/bin/sh
# update feeds, merge with old feeds.
# NOTE: assumes "sfeed_*" executables are in $PATH.

# defaults
sfeedpath="$HOME/.sfeed/feeds"

# load config (evaluate shellscript).
# loadconfig(configfile)
loadconfig() {
	# allow to specify config via argv[1].
	if [ ! x"$1" = x"" ]; then
		# get absolute path of config file.
		config=$(readlink -f "$1")
	else
		# default config location.
		config="$HOME/.sfeed/sfeedrc"
	fi

	# load config: 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
}

# merge raw files.
# merge(oldfile, newfile)
merge() {
	# unique sort by id, title, link.
	# order by timestamp (desc).
	(sort -t '	' -u -k6,6 -k2,2 -k3,3 "$1" "$2" 2>/dev/null) |
	sort -t '	' -k1rn,1
}

# fetch a feed via HTTP/HTTPS etc.
# fetchfeed(url, name, feedfile)
fetchfeed() {
	if curl -H 'User-Agent:' -f -s -S --max-time 15 -z "$3" "$1"; then
		printf "  OK %s %s\n" "$(date +'%H:%M:%S')" "$2" >&2
	else
		printf "FAIL %s %s\n" "$(date +'%H:%M:%S')" "$2" >&2
	fi
}

# convert encoding from one encoding to another.
# convertencoding(from, to)
convertencoding() {
	# if from != to
	if [ ! "$1" = "" ] && [ ! "$2" = "" ] && [ ! "$1" = "$2" ]; then
		iconv -cs -f "$1" -t "$2" 2> /dev/null
	else
		# else no convert, just output
		cat
	fi
}

# fetch and parse feed.
# feed(name, feedurl, [basesiteurl], [encoding])
feed() {
	(name="$1"
	filename="$(printf '%s' "$1" | sed -E 's@[^a-zA-Z0-9]+@_@g')"
	feedurl="$2"
	basesiteurl="$3"
	tmpfeedfile="${sfeedtmpdir}/${filename}"
	tmpencfile=""
	encoding="$4"
	sfeedfile="${sfeedpath}/${filename}"
	if [ ! "${encoding}" = "" ]; then
		fetchfeed "${feedurl}" "${name}" "${sfeedfile}" | \
			convertencoding "${encoding}" "utf-8"
	else # detect encoding.
		tmpencfile="${tmpfeedfile}.enc"
		fetchfeed "${feedurl}" "${name}" "${sfeedfile}" > "${tmpencfile}"
		detectenc=$(sfeed_xmlenc < "${tmpencfile}")
		convertencoding "${detectenc}" "utf-8" < "${tmpencfile}"
	fi | sfeed "${basesiteurl}" | \
		awk -v "n=${name}" '{ print $0 "	" n }' > "${tmpfeedfile}"

	# get new data and merge with old.
	sfeedfilenew="${sfeedpath}/${filename}.new"
	# new feed data is non-empty.
	if [ -s "${tmpfeedfile}" ]; then
		# if file exists, merge
		if [ -e "${sfeedfile}" ]; then
			merge "${sfeedfile}" "${tmpfeedfile}" > "${sfeedfilenew}"
			# overwrite old file with updated file
			mv "${sfeedfilenew}" "${sfeedfile}"
		else
			merge "/dev/null" "${tmpfeedfile}" > "${sfeedfile}"
		fi
	fi) &
}

terminated() {
	isrunning="0"
}

cleanup() {
	# remove temporary files
	rm -rf "${sfeedtmpdir}"
}

feeds() {
	echo "Configuration file \"${config}\" is invalid or does not contain a \"feeds\" function." >&2
	echo "See sfeedrc.example for an example." >&2
}

# load config file.
loadconfig "$1"
# fetch feeds and store in temporary file.
sfeedtmpdir="$(mktemp -d '/tmp/sfeed_XXXXXX')"
# kill whole current process group on ^C.
isrunning="1"
# SIGTERM: signal to terminate parent.
trap -- "terminated" "15"
# SIGINT: kill all running childs >:D
trap -- "kill -TERM -$$" "2"
# make sure path exists.
mkdir -p "${sfeedpath}"
# fetch feeds specified in config file.
feeds
# wait till all feeds are fetched (concurrently).
wait
# cleanup temporary files etc.
cleanup
# if terminated.
[ "${isrunning}" = "0" ] && exit 1