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
8 USE_COMM(NEWTOY(comm, "<2>2321", TOYFLAG_USR|TOYFLAG_BIN))
9 
10 config COMM
11   bool "comm"
12   default y
13   help
14     usage: comm [-123] FILE1 FILE2
15 
16     Read FILE1 and FILE2, which should be ordered, and produce 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 
writeline(const char * line,int col)28 static 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 
comm_main(void)42 void 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] = xopenro(toys.optargs[i]);
52     line[i] = get_line(file[i]);
53   }
54 
55   while (line[0] && line[1]) {
56     int order = strcmp(line[0], line[1]);
57 
58     if (order == 0) {
59       writeline(line[0], 2);
60       for (i = 0; i < 2; i++) {
61         free(line[i]);
62         line[i] = get_line(file[i]);
63       }
64     } else {
65       i = order < 0 ? 0 : 1;
66       writeline(line[i], i);
67       free(line[i]);
68       line[i] = get_line(file[i]);
69     }
70   }
71 
72   /* print rest of the longer file */
73   for (i = line[0] ? 0 : 1; line[i];) {
74     writeline(line[i], i);
75     free(line[i]);
76     line[i] = get_line(file[i]);
77   }
78 
79   if (CFG_TOYBOX_FREE) for (i = 0; i < 2; i++) xclose(file[i]);
80 }
81