1 files changed, 169 insertions, 0 deletions
diff --git a/src/cmd/uniq.c b/src/cmd/uniq.c
new file mode 100644
index 00000000..122fb5ed
--- /dev/null
+++ b/src/cmd/uniq.c
@@ -0,0 +1,169 @@
+/*
+ * Deal with duplicated lines in a file
+ */
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <ctype.h>
+
+#define	SIZE	8000
+
+int	fields	= 0;
+int	letters	= 0;
+int	linec	= 0;
+char	mode;
+int	uniq;
+char	*b1, *b2;
+long	bsize;
+Biobuf	fin;
+Biobuf	fout;
+
+int	gline(char *buf);
+void	pline(char *buf);
+int	equal(char *b1, char *b2);
+char*	skip(char *s);
+
+void
+main(int argc, char *argv[])
+{
+	int f;
+
+	bsize = SIZE;
+	b1 = malloc(bsize);
+	b2 = malloc(bsize);
+	f = 0;
+	while(argc > 1) {
+		if(*argv[1] == '-') {
+			if(isdigit(argv[1][1]))
+				fields = atoi(&argv[1][1]);
+			else
+				mode = argv[1][1];
+			argc--;
+			argv++;
+			continue;
+		}
+		if(*argv[1] == '+') {
+			letters = atoi(&argv[1][1]);
+			argc--;
+			argv++;
+			continue;
+		}
+		f = open(argv[1], 0);
+		if(f < 0) {
+			fprint(2, "cannot open %s\n", argv[1]);
+			exits("open");
+		}
+		break;
+	}
+	if(argc > 2) {
+		fprint(2, "unexpected argument %s\n", argv[2]);
+		exits("arg");
+	}
+	Binit(&fin, f, OREAD);
+	Binit(&fout, 1, OWRITE);
+
+	if(gline(b1))
+		exits(0);
+	for(;;) {
+		linec++;
+		if(gline(b2)) {
+			pline(b1);
+			exits(0);
+		}
+		if(!equal(b1, b2)) {
+			pline(b1);
+			linec = 0;
+			do {
+				linec++;
+				if(gline(b1)) {
+					pline(b2);
+					exits(0);
+				}
+			} while(equal(b2, b1));
+			pline(b2);
+			linec = 0;
+		}
+	}
+}
+
+int
+gline(char *buf)
+{
+	char *p;
+
+	p = Brdline(&fin, '\n');
+	if(p == 0)
+		return 1;
+	if(fin.rdline >= bsize-1) {
+		fprint(2, "line too long\n");
+		exits("too long");
+	}
+	memmove(buf, p, fin.rdline);
+	buf[fin.rdline-1] = 0;
+	return 0;
+}
+
+void
+pline(char *buf)
+{
+
+	switch(mode) {
+
+	case 'u':
+		if(uniq) {
+			uniq = 0;
+			return;
+		}
+		break;
+
+	case 'd':
+		if(uniq)
+			break;
+		return;
+
+	case 'c':
+		Bprint(&fout, "%4d ", linec);
+	}
+	uniq = 0;
+	Bprint(&fout, "%s\n", buf);
+}
+
+int
+equal(char *b1, char *b2)
+{
+	char c;
+
+	if(fields || letters) {
+		b1 = skip(b1);
+		b2 = skip(b2);
+	}
+	for(;;) {
+		c = *b1++;
+		if(c != *b2++) {
+			if(c == 0 && mode == 's')
+				return 1;
+			return 0;
+		}
+		if(c == 0) {
+			uniq++;
+			return 1;
+		}
+	}
+}
+
+char*
+skip(char *s)
+{
+	int nf, nl;
+
+	nf = nl = 0;
+	while(nf++ < fields) {
+		while(*s == ' ' || *s == '\t')
+			s++;
+		while(!(*s == ' ' || *s == '\t' || *s == 0) ) 
+			s++;
+	}
+	while(nl++ < letters && *s != 0) 
+			s++;
+	return s;
+}