1#         $NetBSD: join.awk,v 1.7 2019/10/24 16:52:11 rhialto Exp $
2#
3# Copyright (c) 2002 The NetBSD Foundation, Inc.
4# All rights reserved.
5#
6# This code is derived from software contributed to The NetBSD Foundation
7# by Luke Mewburn of Wasabi Systems.
8#
9# Redistribution and use in source and binary forms, with or without
10# modification, are permitted provided that the following conditions
11# are met:
12# 1. Redistributions of source code must retain the above copyright
13#    notice, this list of conditions and the following disclaimer.
14# 2. Redistributions in binary form must reproduce the above copyright
15#    notice, this list of conditions and the following disclaimer in the
16#    documentation and/or other materials provided with the distribution.
17#
18# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28# POSSIBILITY OF SUCH DAMAGE.
29#
30# join.awk F1 F2
31#         Similar to join(1), this reads a list of words from F1
32#         and outputs lines in F2 with a first word that is in F1.
33#         For purposes of matching the first word, both instances are
34#         canonicalised via unvis(word); the version from F2 is printed.
35#         Neither file needs to be sorted.
36
37function unvis(s) \
38{
39          # XXX: We don't handle the complete range of vis encodings
40          unvis_result = ""
41          while (length(s) > 0) {
42                    unvis_pos = match(s, "\\\\.")
43                    if (unvis_pos == 0) {
44                              unvis_result = unvis_result "" s
45                              s = ""
46                              break
47                    }
48                    # copy the part before the next backslash
49                    unvis_result = unvis_result "" substr(s, 1, unvis_pos - 1)
50                    s = substr(s, unvis_pos)
51                    # process the backslash and next few chars
52                    if (substr(s, 1, 2) == "\\\\") {
53                              # double backslash -> single backslash
54                              unvis_result = unvis_result "\\"
55                              s = substr(s, 3)
56                    } else if (match(s, "\\\\[0-7][0-7][0-7]") == 1) {
57                              # \ooo with three octal digits.
58                              # XXX: use strnum() is that is available
59                              unvis_result = unvis_result "" sprintf("%c", \
60                                        0+substr(s, 2, 1) * 64 + \
61                                        0+substr(s, 3, 1) * 8 + \
62                                        0+substr(s, 4, 1))
63                              s = substr(s, 5)
64                    } else {
65                              # unrecognised escape: keep the literal backslash
66                              printf "%s: %s:%s: unrecognised escape %s\n", \
67                                        ARGV[0], (FILENAME ? FILENAME : "stdin"), FNR, \
68                                        substr(s, 1, 2) \
69                                        >"/dev/stderr"
70                              unvis_result = unvis_result "" substr(s, 1, 1)
71                              s = substr(s, 2)
72                    }
73          }
74          return unvis_result
75}
76
77BEGIN \
78{
79          if (ARGC != 3) {
80                    printf("Usage: join file1 file2\n") >"/dev/stderr"
81                    exit 1
82          }
83          while ( (getline < ARGV[1]) > 0) {
84                    f1 = unvis($1)
85                    words[f1] = $0
86          }
87          delete ARGV[1]
88}
89
90{ f1 = unvis($1) }
91
92f1 in words \
93{
94          $1=""
95          print words[f1] $0
96}
97