(M68*:*:R3V[567]*:*): Use uppercase 'M'.
[glibc.git] / time / tzselect.ksh
blob0f0a3bb28e83360878527bbdd6d3a865104f7f7d
1 #! /bin/ksh
2 # Ask the user about the time zone, and output the resulting TZ value to stdout.
3 # Interact with the user via stderr and stdin.
5 # Contributed by Paul Eggert <eggert@twinsun.com>.
7 # Porting notes:
9 # This script requires several features of the Korn shell.
10 # If your host lacks the Korn shell,
11 # you can use either of the following free programs instead:
13 # Bourne-Again shell (bash)
14 # <URL:ftp://prep.ai.mit.edu:/pub/gnu/bash-1.14.7.tar.gz>
15 # (or any later version)
17 # Public domain ksh
18 # <URL:ftp://ftp.cs.mun.ca:/pub/pdksh/pdksh.tar.gz>
20 # This script also uses several features of modern awk programs.
21 # If your host lacks awk, or has an old awk that does not conform to Posix.2,
22 # you can use either of the following free programs instead:
24 # GNU awk (gawk)
25 # <URL:ftp://prep.ai.mit.edu:/pub/gnu/gawk-3.0.0.tar.gz>
26 # (or any later version)
28 # mawk
29 # <URL:ftp://oxy.edu/public/mawk1.2.2.tar.gz>
30 # (or any later version)
33 # Specify default values for environment variables if they are unset.
34 : ${AWK=awk}
35 : ${TZDIR=$(pwd)}
37 # Check for awk Posix compliance.
38 ($AWK -v x=y 'BEGIN { exit 123 }') </dev/null >/dev/null 2>&1
39 [ $? = 123 ] || {
40 echo >&2 "$0: Sorry, your \`$AWK' program is not Posix compatible."
41 exit 1
44 # Make sure the tables are readable.
45 TZ_COUNTRY_TABLE=$TZDIR/iso3166.tab
46 TZ_ZONE_TABLE=$TZDIR/zone.tab
47 for f in $TZ_COUNTRY_TABLE $TZ_ZONE_TABLE
49 <$f || {
50 echo >&2 "$0: time zone files are not set up correctly"
51 exit 1
53 done
55 newline='
57 IFS=$newline
60 # Work around a bash bug, where $PS3 is sent to stdout.
61 case $(echo 1 | (select x in x; do break; done) 2>/dev/null) in
62 ?*) PS3=
63 esac
66 # Begin the main loop. We come back here if the user wants to retry.
67 while
69 echo >&2 'Please identify a location' \
70 'so that time zone rules can be set correctly.'
72 continent=
73 country=
74 region=
77 # Ask the user for continent or ocean.
79 echo >&2 'Please select a continent or ocean.'
81 select continent in \
82 Africa \
83 Americas \
84 Antarctica \
85 'Arctic Ocean' \
86 Asia \
87 'Atlantic Ocean' \
88 Australia \
89 Europe \
90 'Indian Ocean' \
91 'Pacific Ocean' \
92 'none - I want to specify the time zone using the Posix TZ format.'
94 case $continent in
95 '')
96 echo >&2 'Please enter a number in range.';;
97 ?*)
98 case $continent in
99 Americas) continent=America;;
100 *' '*) continent=$(expr "$continent" : '\([^ ]*\)')
101 esac
102 break
103 esac
104 done
105 case $continent in
107 exit 1;;
108 none)
109 # Ask the user for a Posix TZ string. Check that it conforms.
110 while
111 echo >&2 'Please enter the desired value' \
112 'of the TZ environment variable.'
113 echo >&2 'For example, GST-10 is a zone named GST' \
114 'that is 10 hours ahead (east) of UTC.'
115 read TZ
116 $AWK -v TZ="$TZ" 'BEGIN {
117 tzname = "[^-+,0-9][^-+,0-9][^-+,0-9]+"
118 time = "[0-2]?[0-9](:[0-5][0-9](:[0-5][0-9])?)?"
119 offset = "[-+]?" time
120 date = "(J?[0-9]+|M[0-9]+\.[0-9]+\.[0-9]+)"
121 datetime = "," date "(/" time ")?"
122 tzpattern = "^(:.*|" tzname offset "(" tzname \
123 "(" offset ")?(" datetime datetime ")?)?)$"
124 if (TZ ~ tzpattern) exit 1
125 exit 0
128 echo >&2 "\`$TZ' is not a conforming" \
129 'Posix time zone string.'
130 done
131 TZ_for_date=$TZ;;
133 # Get list of names of countries in the continent or ocean.
134 countries=$($AWK -F'\t' \
135 -v continent="$continent" \
136 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
138 /^#/ { next }
139 $3 ~ ("^" continent "/") {
140 if (!cc_seen[$1]++) cc_list[++ccs] = $1
142 END {
143 while (getline <TZ_COUNTRY_TABLE) {
144 if ($0 !~ /^#/) cc_name[$1] = $2
146 for (i = 1; i <= ccs; i++) {
147 country = cc_list[i]
148 if (cc_name[country]) {
149 country = cc_name[country]
151 print country
154 ' <$TZ_ZONE_TABLE | sort -f)
157 # If there's more than one country, ask the user which one.
158 case $countries in
159 *"$newline"*)
160 echo >&2 'Please select a country.'
161 select country in $countries
163 case $country in
164 '') echo >&2 'Please enter a number in range.';;
165 ?*) break
166 esac
167 done
169 case $country in
170 '') exit 1
171 esac;;
173 country=$countries
174 esac
177 # Get list of names of time zone rule regions in the country.
178 regions=$($AWK -F'\t' \
179 -v country="$country" \
180 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
182 BEGIN {
183 cc = country
184 while (getline <TZ_COUNTRY_TABLE) {
185 if ($0 !~ /^#/ && country == $2) {
186 cc = $1
187 break
191 $1 == cc { print $4 }
192 ' <$TZ_ZONE_TABLE)
195 # If there's more than one region, ask the user which one.
196 case $regions in
197 *"$newline"*)
198 echo >&2 'Please select one of the following' \
199 'time zone regions.'
200 select region in $regions
202 case $region in
203 '') echo >&2 'Please enter a number in range.';;
204 ?*) break
205 esac
206 done
207 case $region in
208 '') exit 1
209 esac;;
211 region=$regions
212 esac
214 # Determine TZ from country and region.
215 TZ=$($AWK -F'\t' \
216 -v country="$country" \
217 -v region="$region" \
218 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
220 BEGIN {
221 cc = country
222 while (getline <TZ_COUNTRY_TABLE) {
223 if ($0 !~ /^#/ && country == $2) {
224 cc = $1
225 break
229 $1 == cc && $4 == region { print $3 }
230 ' <$TZ_ZONE_TABLE)
232 # Make sure the corresponding zoneinfo file exists.
233 TZ_for_date=$TZDIR/$TZ
234 <$TZ_for_date || {
235 echo >&2 "$0: time zone files are not set up correctly"
236 exit 1
238 esac
241 # Use the proposed TZ to output the current date relative to UTC.
242 # Loop until they agree in seconds.
243 # Give up after 8 unsuccessful tries.
245 extra_info=
246 for i in 1 2 3 4 5 6 7 8
248 TZdate=$(LANG=C TZ="$TZ_for_date" date)
249 UTdate=$(LANG=C TZ=UTC0 date)
250 TZsec=$(expr "$TZdate" : '.*:\([0-5][0-9]\)')
251 UTsec=$(expr "$UTdate" : '.*:\([0-5][0-9]\)')
252 case $TZsec in
253 $UTsec)
254 extra_info="
255 Local time is now: $TZdate.
256 Universal Time is now: $UTdate."
257 break
258 esac
259 done
262 # Output TZ info and ask the user to confirm.
264 echo >&2 ""
265 echo >&2 "The following information has been given:"
266 echo >&2 ""
267 case $country+$region in
268 ?*+?*) echo >&2 " $country$newline $region";;
269 ?*+) echo >&2 " $country";;
270 +) echo >&2 " TZ='$TZ'"
271 esac
272 echo >&2 ""
273 echo >&2 "Therefore TZ='$TZ' will be used.$extra_info"
274 echo >&2 "Is the above information OK?"
277 select ok in Yes No
279 case $ok in
280 '') echo >&2 'Please enter 1 for Yes, or 2 for No.';;
281 ?*) break
282 esac
283 done
284 case $ok in
285 '') exit 1;;
286 Yes) break
287 esac
288 do :
289 done
291 # Output the answer.
292 echo "$TZ"