8de8e92017-11-17Henrik Grubbström (Grubba) # Convert tzdata source into a smaller version of itself. # Contributed by Paul Eggert. This file is in the public domain. # This is not a general-purpose converter; it is designed for current tzdata. # 'zic' should treat this script's output as if it were identical to # this script's input. # Return a new rule name. # N_RULE_NAMES keeps track of how many rule names have been generated. function gen_rule_name(alphabet, base, rule_name, n, digit) { alphabet = "" alphabet = alphabet "ABCDEFGHIJKLMNOPQRSTUVWXYZ" alphabet = alphabet "abcdefghijklmnopqrstuvwxyz" alphabet = alphabet "!$%&'()*+,./:;<=>?@[\\]^_`{|}~" base = length(alphabet) rule_name = "" n = n_rule_names++ do { n -= rule_name && n <= base digit = n % base rule_name = substr(alphabet, digit + 1, 1) rule_name n = (n - digit) / base } while (n); return rule_name } # Process an input line and save it for later output. function process_input_line(line, field, end, i, n, startdef) { # Remove comments, normalize spaces, and append a space to each line. sub(/#.*/, "", line) line = line " "
2b14ff2018-09-05Henrik Grubbström (Grubba)  gsub(/[[:space:]]+/, " ", line)
8de8e92017-11-17Henrik Grubbström (Grubba)  # Abbreviate keywords. Do not abbreviate "Link" to just "L", # as pre-2017c zic erroneously diagnoses "Li" as ambiguous. sub(/^Link /, "Li ", line) sub(/^Rule /, "R ", line) sub(/^Zone /, "Z ", line) # SystemV rules are not needed. if (line ~ /^R SystemV /) return # Replace FooAsia rules with the same rules without "Asia", as they # are duplicates. if (match(line, /[^ ]Asia /)) { if (line ~ /^R /) return line = substr(line, 1, RSTART) substr(line, RSTART + 5) } # Abbreviate times. while (match(line, /[: ]0+[0-9]/)) line = substr(line, 1, RSTART) substr(line, RSTART + RLENGTH - 1) while (match(line, /:0[^:]/)) line = substr(line, 1, RSTART - 1) substr(line, RSTART + 2) # Abbreviate weekday names. Do not abbreviate "Sun" and "Sat", as # pre-2017c zic erroneously diagnoses "Su" and "Sa" as ambiguous. while (match(line, / (last)?(Mon|Wed|Fri)[ <>]/)) { end = RSTART + RLENGTH line = substr(line, 1, end - 4) substr(line, end - 1) } while (match(line, / (last)?(Tue|Thu)[ <>]/)) { end = RSTART + RLENGTH line = substr(line, 1, end - 3) substr(line, end - 1) } # Abbreviate "max", "only" and month names. # Do not abbreviate "min", as pre-2017c zic erroneously diagnoses "mi" # as ambiguous. gsub(/ max /, " ma ", line) gsub(/ only /, " o ", line) gsub(/ Jan /, " Ja ", line) gsub(/ Feb /, " F ", line) gsub(/ Apr /, " Ap ", line) gsub(/ Aug /, " Au ", line) gsub(/ Sep /, " S ", line) gsub(/ Oct /, " O ", line) gsub(/ Nov /, " N ", line) gsub(/ Dec /, " D ", line) # Strip leading and trailing space. sub(/^ /, "", line) sub(/ $/, "", line) # Remove unnecessary trailing zero fields. sub(/ 0+$/, "", line) # Remove unnecessary trailing days-of-month "1".
2b14ff2018-09-05Henrik Grubbström (Grubba)  if (match(line, /[[:alpha:]] 1$/))
8de8e92017-11-17Henrik Grubbström (Grubba)  line = substr(line, 1, RSTART) # Remove unnecessary trailing " Ja" (for January). sub(/ Ja$/, "", line) n = split(line, field) # Abbreviate rule names. i = field[1] == "Z" ? 4 : field[1] == "Li" ? 0 : 2 if (i && field[i] ~ /^[^-+0-9]/) { if (!rule[field[i]]) rule[field[i]] = gen_rule_name() field[i] = rule[field[i]] } # If this zone supersedes an earlier one, delete the earlier one # from the saved output lines. startdef = "" if (field[1] == "Z") zonename = startdef = field[2] else if (field[1] == "Li") zonename = startdef = field[3] else if (field[1] == "R") zonename = "" if (startdef) { i = zonedef[startdef] if (i) { do output_line[i - 1] = "" while (output_line[i++] ~ /^[-+0-9]/); } } zonedef[zonename] = nout + 1 # Save the line for later output. line = field[1] for (i = 2; i <= n; i++) line = line " " field[i] output_line[nout++] = line } function output_saved_lines(i) { for (i = 0; i < nout; i++) if (output_line[i]) print output_line[i] } BEGIN { print "# This zic input file is in the public domain." }
2b14ff2018-09-05Henrik Grubbström (Grubba) /^[[:space:]]*[^#[:space:]]/ {
8de8e92017-11-17Henrik Grubbström (Grubba)  process_input_line($0) } END { output_saved_lines() }