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-rw-r--r--coreutils/comm.c155
1 files changed, 155 insertions, 0 deletions
diff --git a/coreutils/comm.c b/coreutils/comm.c
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+++ b/coreutils/comm.c
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+/* vi: set sw=4 ts=4: */
+/*
+ * Mini comm implementation for busybox
+ *
+ * Copyright (C) 2005 by Robert Sullivan <cogito.ergo.cogito@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "busybox.h"
+
+#define COMM_OPT_1 0x01
+#define COMM_OPT_2 0x02
+#define COMM_OPT_3 0x04
+
+/* These three variables control behaviour if non-zero */
+
+static int only_file_1;
+static int only_file_2;
+static int both;
+
+/* writeline outputs the input given, appropriately aligned according to class */
+static void writeline (char *line, int class) {
+ switch (class) {
+ case 1: if (!only_file_1)
+ return;
+ break;
+ case 2: if (!only_file_2)
+ return;
+ if (only_file_1)
+ putchar('\t');
+ break;
+ case 3: if (!both)
+ return;
+ if (only_file_1)
+ putchar('\t');
+ if (only_file_2)
+ putchar('\t');
+ break;
+ }
+ fputs(line, stdout);
+}
+
+/* This is the real core of the program - lines are compared here */
+static int cmp_files(char **infiles) {
+
+ char thisline[2][100];
+ FILE *streams[2];
+ int i = 0;
+
+ for (i = 0; i < 2; i++) {
+ streams[i] = (strcmp(infiles[i], "=") == 0 ? stdin : fopen(infiles[i], "r"));
+ fgets(thisline[i], 100, streams[i]);
+ }
+
+ while (thisline[0] || thisline[1]) {
+
+ int order = 0;
+ int tl0_len = strlen(thisline[0]);
+ int tl1_len = strlen(thisline[1]);
+ if (!thisline[0])
+ order = 1;
+ else if (!thisline[1])
+ order = -1;
+ else {
+ order = memcmp(thisline[0], thisline[1], tl0_len < tl1_len ? tl0_len : tl1_len);
+ if (!order)
+ order = tl0_len < tl1_len ? -1 : tl0_len != tl1_len;
+ }
+
+ if ((order == 0) && (!feof(streams[0])) && (!feof(streams[1])))
+ writeline(thisline[1], 3);
+ else if ((order > 0) && (!feof(streams[1])))
+ writeline(thisline[1], 2);
+ else if ((order < 0) && (!feof(streams[0])))
+ writeline(thisline[0], 1);
+
+ if (feof(streams[0]) && feof(streams[1])) {
+ fclose(streams[0]);
+ fclose(streams[1]);
+ break;
+ }
+ else if (feof(streams[0])) {
+
+ while (!feof(streams[1])) {
+ if (order < 0)
+ writeline(thisline[1], 2);
+ fgets(thisline[1], 100, streams[1]);
+ }
+ fclose(streams[0]);
+ fclose(streams[1]);
+ break;
+ }
+ else if (feof(streams[1])) {
+
+ while (!feof(streams[0])) {
+ if (order > 0)
+ writeline(thisline[0], 1);
+ fgets(thisline[0], 100, streams[0]);
+ }
+ fclose(streams[0]);
+ fclose(streams[1]);
+ break;
+ }
+ else {
+ if (order >= 0)
+ fgets(thisline[1], 100, streams[1]);
+ if (order <= 0)
+ fgets(thisline[0], 100, streams[0]);
+ }
+ }
+
+ return 0;
+}
+
+int comm_main (int argc, char **argv) {
+
+ unsigned long opt;
+ only_file_1 = 1;
+ only_file_2 = 1;
+ both = 1;
+
+ opt = bb_getopt_ulflags(argc, argv, "123");
+
+ if ((opt & 0x80000000UL) || (optind == argc)) {
+ bb_show_usage();
+ }
+
+ if (opt & COMM_OPT_1)
+ only_file_1 = 0;
+ if (opt & COMM_OPT_2)
+ only_file_2 = 0;
+ if (opt & COMM_OPT_3)
+ both = 0;
+
+ exit(cmp_files(argv + optind) == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+}