uniq: Initial commit

Makefile

@@ -54,6 +54,7 @@ SRC = \
 	true.c     \
 	tty.c      \
 	uname.c    \
+	uniq.c     \
 	seq.c      \
 	wc.c       \
 	yes.c
@@ -66,7 +67,7 @@ all: $(BIN)
 
 $(OBJ): util.h config.mk
 $(BIN): util.a
-cat.o fold.o grep.o nl.o sort.o tail.o: text.h
+cat.o fold.o grep.o nl.o sort.o tail.o uniq.o: text.h
 cp.o mv.o rm.o: fs.h
 
 .o:

uniq.c

@@ -0,0 +1,96 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "text.h"
+#include "util.h"
+
+static void uniq_line(char *);
+static void uniq(FILE *, const char *);
+static void uniq_finish(void);
+
+static const char *countfmt = "";
+static bool dflag = false;
+static bool uflag = false;
+
+static char *prev_line = NULL;
+static long prev_line_count = 0;
+
+int
+main(int argc, char *argv[])
+{
+	int c;
+	FILE *fp;
+
+	while((c = getopt(argc, argv, "cdu")) != -1)
+		switch(c) {
+		case 'c':
+			countfmt = "%7ld ";
+			break;
+		case 'd':
+			dflag = true;
+			break;
+		case 'u':
+			uflag = true;
+			break;
+		default:
+			exit(2);
+		}
+
+	if(optind == argc)
+		uniq(stdin, "<stdin>");
+	else for(; optind < argc; optind++) {
+		if(!(fp = fopen(argv[optind], "r")))
+			eprintf("fopen %s:", argv[optind]);
+		uniq(fp, argv[optind]);
+		fclose(fp);
+	}
+	uniq_finish();
+
+	return EXIT_SUCCESS;
+}
+
+void
+uniq_line(char *l)
+{
+	bool lines_equal = ((l == NULL) || (prev_line == NULL))
+		? l == prev_line
+		: !strcmp(l, prev_line);
+
+	if(lines_equal) {
+		++prev_line_count;
+		return;
+	}
+
+	if(prev_line != NULL) {
+		if((prev_line_count == 1 && !dflag) ||
+		   (prev_line_count != 1 && !uflag)) {
+			printf(countfmt, prev_line_count);
+			fputs(prev_line, stdout);
+		}
+		free(prev_line);
+		prev_line = NULL;
+	}
+
+	if(l && !(prev_line = strdup(l)))
+		eprintf("strdup:");
+	prev_line_count = 1;
+}
+
+void
+uniq(FILE *fp, const char *str)
+{
+	char *buf = NULL;
+	size_t size = 0;
+
+	while(afgets(&buf, &size, fp))
+		uniq_line(buf);
+}
+
+void
+uniq_finish()
+{
+	uniq_line(NULL);
+}