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>.
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 # <a href=ftp://ftp.gnu.org/pub/gnu/>
14 # Bourne-Again shell (bash)
17 # <a href=ftp://ftp.cs.mun.ca/pub/pdksh/pdksh.tar.gz>
21 # This script also uses several features of modern awk programs.
22 # If your host lacks awk, or has an old awk that does not conform to Posix.2,
23 # you can use either of the following free programs instead:
25 # <a href=ftp://ftp.gnu.org/pub/gnu/>
29 # <a href=ftp://ftp.whidbey.net/pub/brennan/>
34 # Specify default values for environment variables if they are unset.
38 # Check for awk Posix compliance.
39 ($AWK -v x=y 'BEGIN { exit 123 }') </dev/null >/dev/null 2>&1
41 echo >&2 "$0: Sorry, your \`$AWK' program is not Posix compatible."
45 # Make sure the tables are readable.
46 TZ_COUNTRY_TABLE=$TZDIR/iso3166.tab
47 TZ_ZONE_TABLE=$TZDIR/zone.tab
48 for f in $TZ_COUNTRY_TABLE $TZ_ZONE_TABLE
51 echo >&2 "$0: time zone files are not set up correctly"
61 # Work around a bug in bash 1.14.7 and earlier, where $PS3 is sent to stdout.
62 case $(echo 1 | (select x in x; do break; done) 2>/dev/null) in
67 # Begin the main loop. We come back here if the user wants to retry.
70 echo >&2 'Please identify a location' \
71 'so that time zone rules can be set correctly.'
78 # Ask the user for continent or ocean.
80 echo >&2 'Please select a continent or ocean.'
93 'none - I want to specify the time zone using the Posix TZ format.'
97 echo >&2 'Please enter a number in range.';;
100 Americas) continent=America;;
101 *' '*) continent=$(expr "$continent" : '\([^ ]*\)')
110 # Ask the user for a Posix TZ string. Check that it conforms.
112 echo >&2 'Please enter the desired value' \
113 'of the TZ environment variable.'
114 echo >&2 'For example, GST-10 is a zone named GST' \
115 'that is 10 hours ahead (east) of UTC.'
117 $AWK -v TZ="$TZ" 'BEGIN {
118 tzname = "[^-+,0-9][^-+,0-9][^-+,0-9]+"
119 time = "[0-2]?[0-9](:[0-5][0-9](:[0-5][0-9])?)?"
120 offset = "[-+]?" time
121 date = "(J?[0-9]+|M[0-9]+\.[0-9]+\.[0-9]+)"
122 datetime = "," date "(/" time ")?"
123 tzpattern = "^(:.*|" tzname offset "(" tzname \
124 "(" offset ")?(" datetime datetime ")?)?)$"
125 if (TZ ~ tzpattern) exit 1
129 echo >&2 "\`$TZ' is not a conforming" \
130 'Posix time zone string.'
134 # Get list of names of countries in the continent or ocean.
135 countries=$($AWK -F'\t' \
136 -v continent="$continent" \
137 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
140 $3 ~ ("^" continent "/") {
141 if (!cc_seen[$1]++) cc_list[++ccs] = $1
144 while (getline <TZ_COUNTRY_TABLE) {
145 if ($0 !~ /^#/) cc_name[$1] = $2
147 for (i = 1; i <= ccs; i++) {
149 if (cc_name[country]) {
150 country = cc_name[country]
155 ' <$TZ_ZONE_TABLE | sort -f)
158 # If there's more than one country, ask the user which one.
161 echo >&2 'Please select a country.'
162 select country in $countries
165 '') echo >&2 'Please enter a number in range.';;
178 # Get list of names of time zone rule regions in the country.
179 regions=$($AWK -F'\t' \
180 -v country="$country" \
181 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
185 while (getline <TZ_COUNTRY_TABLE) {
186 if ($0 !~ /^#/ && country == $2) {
192 $1 == cc { print $4 }
196 # If there's more than one region, ask the user which one.
199 echo >&2 'Please select one of the following' \
201 select region in $regions
204 '') echo >&2 'Please enter a number in range.';;
215 # Determine TZ from country and region.
217 -v country="$country" \
218 -v region="$region" \
219 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
223 while (getline <TZ_COUNTRY_TABLE) {
224 if ($0 !~ /^#/ && country == $2) {
230 $1 == cc && $4 == region { print $3 }
233 # Make sure the corresponding zoneinfo file exists.
234 TZ_for_date=$TZDIR/$TZ
236 echo >&2 "$0: time zone files are not set up correctly"
242 # Use the proposed TZ to output the current date relative to UTC.
243 # Loop until they agree in seconds.
244 # Give up after 8 unsuccessful tries.
247 for i in 1 2 3 4 5 6 7 8
249 TZdate=$(LANG=C TZ="$TZ_for_date" date)
250 UTdate=$(LANG=C TZ=UTC0 date)
251 TZsec=$(expr "$TZdate" : '.*:\([0-5][0-9]\)')
252 UTsec=$(expr "$UTdate" : '.*:\([0-5][0-9]\)')
256 Local time is now: $TZdate.
257 Universal Time is now: $UTdate."
263 # Output TZ info and ask the user to confirm.
266 echo >&2 "The following information has been given:"
268 case $country+$region in
269 ?*+?*) echo >&2 " $country$newline $region";;
270 ?*+) echo >&2 " $country";;
271 +) echo >&2 " TZ='$TZ'"
274 echo >&2 "Therefore TZ='$TZ' will be used.$extra_info"
275 echo >&2 "Is the above information OK?"
281 '') echo >&2 'Please enter 1 for Yes, or 2 for No.';;