1/* comm.c - select or reject lines common to two files
2 *
3 * Copyright 2012 Ilya Kuzmich <ikv@safe-mail.net>
4 *
5 * See http://opengroup.org/onlinepubs/9699919799/utilities/comm.html
6
7// <# and ># take single digit, so 321 define flags
8USE_COMM(NEWTOY(comm, "<2>2321", TOYFLAG_USR|TOYFLAG_BIN))
9
10config COMM
11  bool "comm"
12  default y
13  help
14    usage: comm [-123] FILE1 FILE2
15
16    Reads FILE1 and FILE2, which should be ordered, and produces three text
17    columns as output: lines only in FILE1; lines only in FILE2; and lines
18    in both files. Filename "-" is a synonym for stdin.
19
20    -1 suppress the output column of lines unique to FILE1
21    -2 suppress the output column of lines unique to FILE2
22    -3 suppress the output column of lines duplicated in FILE1 and FILE2
23*/
24
25#define FOR_comm
26#include "toys.h"
27
28static void writeline(const char *line, int col)
29{
30  if (col == 0 && toys.optflags & FLAG_1) return;
31  else if (col == 1) {
32    if (toys.optflags & FLAG_2) return;
33    if (!(toys.optflags & FLAG_1)) putchar('\t');
34  } else if (col == 2) {
35    if (toys.optflags & FLAG_3) return;
36    if (!(toys.optflags & FLAG_1)) putchar('\t');
37    if (!(toys.optflags & FLAG_2)) putchar('\t');
38  }
39  puts(line);
40}
41
42void comm_main(void)
43{
44  int file[2];
45  char *line[2];
46  int i;
47
48  if (toys.optflags == 7) return;
49
50  for (i = 0; i < 2; i++) {
51    file[i] = strcmp("-", toys.optargs[i])
52      ? xopen(toys.optargs[i], O_RDONLY) : 0;
53    line[i] = get_line(file[i]);
54  }
55
56  while (line[0] && line[1]) {
57    int order = strcmp(line[0], line[1]);
58
59    if (order == 0) {
60      writeline(line[0], 2);
61      for (i = 0; i < 2; i++) {
62        free(line[i]);
63        line[i] = get_line(file[i]);
64      }
65    } else {
66      i = order < 0 ? 0 : 1;
67      writeline(line[i], i);
68      free(line[i]);
69      line[i] = get_line(file[i]);
70    }
71  }
72
73  /* print rest of the longer file */
74  for (i = line[0] ? 0 : 1; line[i];) {
75    writeline(line[i], i);
76    free(line[i]);
77    line[i] = get_line(file[i]);
78  }
79
80  if (CFG_TOYBOX_FREE) for (i = 0; i < 2; i++) xclose(file[i]);
81}
82