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 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
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] = 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