freebsd-nq/ziguard.awk
2018-03-24 04:41:49 +00:00

63 lines
1.7 KiB
Awk

# Convert tzdata source into vanguard or rearguard form.
# Contributed by Paul Eggert. This file is in the public domain.
# This is not a general-purpose converter; it is designed for current tzdata.
#
# When converting to vanguard form, the output can use negative SAVE
# values.
#
# When converting to rearguard form, the output uses only nonnegative
# SAVE values. The idea is for the output data to simulate the behavior
# of the input data as best it can within the constraints of the
# rearguard format.
BEGIN {
dst_type["vanguard.zi"] = 1
dst_type["main.zi"] = 1
dst_type["rearguard.zi"] = 1
# The command line should set OUTFILE to the name of the output file.
if (!dst_type[outfile]) exit 1
vanguard = outfile == "vanguard.zi"
}
/^Zone/ { zone = $2 }
outfile != "main.zi" {
in_comment = /^#/
# If this line should differ due to Ireland using negative SAVE values,
# uncomment the desired version and comment out the undesired one.
Rule_Eire = /^#?Rule[\t ]+Eire[\t ]/
Zone_Dublin_post_1968 \
= (zone == "Europe/Dublin" && /^#?[\t ]+[01]:00[\t ]/ \
&& (!$(in_comment + 4) || 1968 < $(in_comment + 4)))
if (Rule_Eire || Zone_Dublin_post_1968) {
if ((Rule_Eire \
|| (Zone_Dublin_post_1968 && $(in_comment + 3) == "IST/GMT")) \
== vanguard) {
sub(/^#/, "")
} else if (/^[^#]/) {
sub(/^/, "#")
}
}
}
# If a Link line is followed by a Zone line for the same data, comment
# out the Link line. This can happen if backzone overrides a Link
# with a Zone.
/^Link/ {
linkline[$3] = NR
}
/^Zone/ {
sub(/^Link/, "#Link", line[linkline[$2]])
}
{ line[NR] = $0 }
END {
for (i = 1; i <= NR; i++)
print line[i]
}