add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/uniq.c

@@ -0,0 +1,187 @@
+/* uniq - compact repeated lines		Author: John Woods */
+/* Uniq [-udc] [-n] [+n] [infile [outfile]]
+ *
+ *	Written 02/08/86 by John Woods, placed into public domain.  Enjoy.
+ *
+ */
+
+/* If the symbol WRITE_ERROR is defined, uniq will exit(1) if it gets a
+ * write error on the output.  This is not (of course) how V7 uniq does it,
+ * so undefine the symbol if you want to lose your output to a full disk
+ */
+
+#define WRITE_ERROR 1
+#define isdigit(c) (c >= '0' && c <= '9')
+#include <errno.h>
+#include <stdio.h>
+
+FILE *fopen();
+char buffer[BUFSIZ];
+int uflag = 1;			/* default is union of -d and -u outputs */
+int dflag = 1;			/* flags are mutually exclusive */
+int cflag = 0;
+int fields = 0;
+int chars = 0;
+
+FILE *xfopen(fn, mode)
+char *fn, *mode;
+{
+  FILE *p;
+  extern int errno;
+  extern char *sys_errlist[];
+
+  if ((p = fopen(fn, mode)) == NULL) {
+	perror("uniq");
+	fflush(stdout);
+	exit(1);
+  }
+  return(p);
+}
+
+main(argc, argv)
+char *argv[];
+{
+  char *p;
+  int inf = -1, outf;
+
+  setbuf(stdout, buffer);
+  for (--argc, ++argv; argc > 0 && (**argv == '-' || **argv == '+');
+       --argc, ++argv) {
+	if (**argv == '+')
+		chars = atoi(*argv + 1);
+	else if (isdigit(argv[0][1]))
+		fields = atoi(*argv + 1);
+	else if (argv[0][1] == '\0')
+		inf = 0;	/* - is stdin */
+	else
+		for (p = *argv + 1; *p; p++) {
+			switch (*p) {
+			    case 'd':
+				dflag = 1;
+				uflag = 0;
+				break;
+			    case 'u':
+				uflag = 1;
+				dflag = 0;
+				break;
+			    case 'c':	cflag = 1;	break;
+			    default:	usage();
+			}
+		}
+  }
+
+  /* Input file */
+  if (argc == 0)
+	inf = 0;
+  else if (inf == -1) {		/* if - was not given */
+	fclose(stdin);
+	xfopen(*argv++, "r");
+	argc--;
+  }
+  if (argc == 0)
+	outf = 1;
+  else {
+	fclose(stdout);
+	xfopen(*argv++, "w");
+	argc--;
+  }
+
+  uniq();
+  fflush(stdout);
+  exit(0);
+}
+
+char *skip(s)
+char *s;
+{
+  int n;
+
+  /* Skip fields */
+  for (n = fields; n > 0; --n) {
+	/* Skip blanks */
+	while (*s && (*s == ' ' || *s == '\t')) s++;
+	if (!*s) return s;
+	while (*s && (*s != ' ' && *s != '\t')) s++;
+	if (!*s) return s;
+  }
+
+  /* Skip characters */
+  for (n = chars; n > 0; --n) {
+	if (!*s) return s;
+	s++;
+  }
+  return s;
+}
+
+int equal(s1, s2)
+char *s1, *s2;
+{
+  return !strcmp(skip(s1), skip(s2));
+}
+
+
+show(line, count)
+char *line;
+{
+  if (cflag)
+	printf("%4d %s", count, line);
+  else {
+	if ((uflag && count == 1) || (dflag && count != 1))
+		printf("%s", line);
+  }
+}
+
+/* The meat of the whole affair */
+char *nowline, *prevline, buf1[1024], buf2[1024];
+
+uniq()
+{
+  char *p;
+  int seen;
+
+  /* Setup */
+  prevline = buf1;
+  if (getline(prevline, 1024) < 0) return(0);
+  seen = 1;
+  nowline = buf2;
+
+  /* Get nowline and compare if not equal, dump prevline and swap
+   * pointers else continue, bumping seen count */
+  while (getline(nowline, 1024) > 0) {
+	if (!equal(prevline, nowline)) {
+		show(prevline, seen);
+		seen = 1;
+		p = nowline;
+		nowline = prevline;
+		prevline = p;
+	} else
+		seen += 1;
+  }
+  show(prevline, seen);
+  return 0;
+}
+
+usage()
+{
+  std_err("Usage: uniq [-udc] [+n] [-n] [input [output]]\n");
+}
+
+
+int getline(buf, count)
+char *buf;
+int count;
+{
+  int c;
+  int ct = 0;
+
+  while (ct++ < count) {
+	c = getc(stdin);
+	if (c < 0) return(-1);
+	*buf++ = c;
+	if (c == '\n') {
+		*buf++ = 0;
+		return(ct);
+	}
+  }
+  return(ct);
+}