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+/* vi: set sw=4 ts=4:
+ *
+ * comm.c - select or reject lines common to two files
+ *
+ * Copyright 2012 Ilya Kuzmich <ikv@safe-mail.net>
+ *
+ * See http://pubs.opengroup.org/onlinepubs/009695399/utilities/comm.html
+
+USE_COMM(NEWTOY(comm, "123", TOYFLAG_USR|TOYFLAG_BIN))
+
+config COMM
+ bool "comm"
+ default n
+ help
+ usage: comm [-123] FILE1 FILE2
+
+ Reads FILE1 and FILE2, which should be ordered, and produces three text
+ columns as output: lines only in FILE1; lines only in FILE2; and lines
+ in both files. Filename "-" is a synonym for stdin.
+
+ -1 suppress the output column of lines unique to FILE1
+ -2 suppress the output column of lines unique to FILE2
+ -3 suppress the output column of lines duplicated in FILE1 and FILE2
+*/
+
+#include "toys.h"
+
+#define FLAG_SUPPRESS_3 1
+#define FLAG_SUPPRESS_2 2
+#define FLAG_SUPPRESS_1 4
+
+static void writeline(const char *line, int col)
+{
+ if (col == 0 && toys.optflags & FLAG_SUPPRESS_1) return;
+ else if (col == 1) {
+ if (toys.optflags & FLAG_SUPPRESS_2) return;
+ if (!(toys.optflags & FLAG_SUPPRESS_1)) putchar('\t');
+ } else if (col == 2) {
+ if (toys.optflags & FLAG_SUPPRESS_3) return;
+ if (!(toys.optflags & FLAG_SUPPRESS_1)) putchar('\t');
+ if (!(toys.optflags & FLAG_SUPPRESS_2)) putchar('\t');
+ }
+ puts(line);
+}
+
+void comm_main(void)
+{
+ int file[2];
+ char *line[2];
+ int i;
+
+ if (toys.optc != 2)
+ perror_exit("exactly 2 operands required");
+
+ if (toys.optflags == (FLAG_SUPPRESS_1 | FLAG_SUPPRESS_2 | FLAG_SUPPRESS_3))
+ return;
+
+ for (i = 0; i < 2; i++) {
+ file[i] = strcmp("-", toys.optargs[i]) ? xopen(toys.optargs[i], O_RDONLY) : 0;
+ line[i] = get_line(file[i]);
+ }
+
+ while (line[0] && line[1]) {
+ int order = strcmp(line[0], line[1]);
+
+ if (order == 0) {
+ writeline(line[0], 2);
+ for (i = 0; i < 2; i++) {
+ free(line[i]);
+ line[i] = get_line(file[i]);
+ }
+ } else {
+ i = order < 0 ? 0 : 1;
+ writeline(line[i], i);
+ free(line[i]);
+ line[i] = get_line(file[i]);
+ }
+ }
+
+ /* print rest of the longer file */
+ for (i = line[0] ? 0 : 1; line[i];) {
+ writeline(line[i], i);
+ free(line[i]);
+ line[i] = get_line(file[i]);
+ }
+
+ if (CFG_TOYBOX_FREE) {
+ for (i = 0; i < 2; i--)
+ xclose(file[i]);
+ }
+}