1 files changed, 373 insertions, 0 deletions
diff --git a/misc-utils/look.c b/misc-utils/look.c
new file mode 100644
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--- /dev/null
+++ b/misc-utils/look.c
@@ -0,0 +1,373 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * David Hitz of Auspex Systems, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+ /* 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
+  * - added Native Language Support
+  */
+
+/*
+ * look -- find lines in a sorted list.
+ *
+ * The man page said that TABs and SPACEs participate in -d comparisons.
+ * In fact, they were ignored.  This implements historic practice, not
+ * the manual page.
+ */
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <ctype.h>
+#include <getopt.h>
+
+#include "nls.h"
+#include "xalloc.h"
+#include "pathnames.h"
+#include "closestream.h"
+
+#define	EQUAL		0
+#define	GREATER		1
+#define	LESS		(-1)
+
+static int dflag, fflag;
+/* uglified the source a bit with globals, so that we only need
+   to allocate comparbuf once */
+static int stringlen;
+static char *string;
+static char *comparbuf;
+
+static char *binary_search (char *, char *);
+static int compare (char *, char *);
+static char *linear_search (char *, char *);
+static int look (char *, char *);
+static void print_from (char *, char *);
+static void __attribute__((__noreturn__)) usage(void);
+
+int
+main(int argc, char *argv[])
+{
+	struct stat sb;
+	int ch, fd, termchar;
+	char *back, *file, *front, *p;
+
+	static const struct option longopts[] = {
+		{"alternative", no_argument, NULL, 'a'},
+		{"alphanum", no_argument, NULL, 'd'},
+		{"ignore-case", no_argument, NULL, 'f'},
+		{"terminate", required_argument, NULL, 't'},
+		{"version", no_argument, NULL, 'V'},
+		{"help", no_argument, NULL, 'h'},
+		{NULL, 0, NULL, 0}
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+	close_stdout_atexit();
+
+	if ((file = getenv("WORDLIST")) && !access(file, R_OK))
+		/* use the WORDLIST */;
+	else
+		file = _PATH_WORDS;
+
+	termchar = '\0';
+	string = NULL;		/* just for gcc */
+
+	while ((ch = getopt_long(argc, argv, "adft:Vh", longopts, NULL)) != -1)
+		switch(ch) {
+		case 'a':
+			file = _PATH_WORDS_ALT;
+			break;
+		case 'd':
+			dflag = 1;
+			break;
+		case 'f':
+			fflag = 1;
+			break;
+		case 't':
+			termchar = *optarg;
+			break;
+		case 'V':
+			print_version(EXIT_SUCCESS);
+		case 'h':
+			usage();
+		default:
+			errtryhelp(EXIT_FAILURE);
+		}
+	argc -= optind;
+	argv += optind;
+
+	switch (argc) {
+	case 2:				/* Don't set -df for user. */
+		string = *argv++;
+		file = *argv;
+		break;
+	case 1:				/* But set -df by default. */
+		dflag = fflag = 1;
+		string = *argv;
+		break;
+	default:
+		warnx(_("bad usage"));
+		errtryhelp(EXIT_FAILURE);
+	}
+
+	if (termchar != '\0' && (p = strchr(string, termchar)) != NULL)
+		*++p = '\0';
+
+	if ((fd = open(file, O_RDONLY, 0)) < 0 || fstat(fd, &sb))
+		err(EXIT_FAILURE, "%s", file);
+	front = mmap(NULL, (size_t) sb.st_size, PROT_READ,
+		     MAP_SHARED, fd, (off_t) 0);
+	if
+#ifdef MAP_FAILED
+		(front == MAP_FAILED)
+#else
+		((void *)(front) <= (void *)0)
+#endif
+			err(EXIT_FAILURE, "%s", file);
+	back = front + sb.st_size;
+	return look(front, back);
+}
+
+static int
+look(char *front, char *back)
+{
+	int ch;
+	char *readp, *writep;
+
+	/* Reformat string to avoid doing it multiple times later. */
+	if (dflag) {
+		for (readp = writep = string; (ch = *readp++) != 0;) {
+			if (isalnum(ch) || isblank(ch))
+				*(writep++) = ch;
+		}
+		*writep = '\0';
+		stringlen = writep - string;
+	} else
+		stringlen = strlen(string);
+
+	comparbuf = xmalloc(stringlen+1);
+
+	front = binary_search(front, back);
+	front = linear_search(front, back);
+
+	if (front)
+		print_from(front, back);
+
+	free(comparbuf);
+
+	return (front ? 0 : 1);
+}
+
+
+/*
+ * Binary search for "string" in memory between "front" and "back".
+ *
+ * This routine is expected to return a pointer to the start of a line at
+ * *or before* the first word matching "string".  Relaxing the constraint
+ * this way simplifies the algorithm.
+ *
+ * Invariants:
+ * 	front points to the beginning of a line at or before the first
+ *	matching string.
+ *
+ * 	back points to the beginning of a line at or after the first
+ *	matching line.
+ *
+ * Advancing the Invariants:
+ *
+ * 	p = first newline after halfway point from front to back.
+ *
+ * 	If the string at "p" is not greater than the string to match,
+ *	p is the new front.  Otherwise it is the new back.
+ *
+ * Termination:
+ *
+ * 	The definition of the routine allows it return at any point,
+ *	since front is always at or before the line to print.
+ *
+ * 	In fact, it returns when the chosen "p" equals "back".  This
+ *	implies that there exists a string is least half as long as
+ *	(back - front), which in turn implies that a linear search will
+ *	be no more expensive than the cost of simply printing a string or two.
+ *
+ * 	Trying to continue with binary search at this point would be
+ *	more trouble than it's worth.
+ */
+#define	SKIP_PAST_NEWLINE(p, back) \
+	while (p < back && *p++ != '\n')
+
+static char *
+binary_search(char *front, char *back)
+{
+	char *p;
+
+	p = front + (back - front) / 2;
+	SKIP_PAST_NEWLINE(p, back);
+
+	/*
+	 * If the file changes underneath us, make sure we don't
+	 * infinitely loop.
+	 */
+	while (p < back && back > front) {
+		if (compare(p, back) == GREATER)
+			front = p;
+		else
+			back = p;
+		p = front + (back - front) / 2;
+		SKIP_PAST_NEWLINE(p, back);
+	}
+	return (front);
+}
+
+/*
+ * Find the first line that starts with string, linearly searching from front
+ * to back.
+ *
+ * Return NULL for no such line.
+ *
+ * This routine assumes:
+ *
+ * 	o front points at the first character in a line.
+ *	o front is before or at the first line to be printed.
+ */
+static char *
+linear_search(char *front, char *back)
+{
+	while (front < back) {
+		switch (compare(front, back)) {
+		case EQUAL:		/* Found it. */
+			return (front);
+		case LESS:		/* No such string. */
+			return (NULL);
+		case GREATER:		/* Keep going. */
+			break;
+		}
+		SKIP_PAST_NEWLINE(front, back);
+	}
+	return (NULL);
+}
+
+/*
+ * Print as many lines as match string, starting at front.
+ */
+static void
+print_from(char *front, char *back)
+{
+	int eol;
+
+	while (front < back && compare(front, back) == EQUAL) {
+		if (compare(front, back) == EQUAL) {
+			eol = 0;
+			while (front < back && !eol) {
+				if (putchar(*front) == EOF)
+					err(EXIT_FAILURE, "stdout");
+				if (*front++ == '\n')
+					eol = 1;
+			}
+		} else
+			SKIP_PAST_NEWLINE(front, back);
+	}
+}
+
+/*
+ * Return LESS, GREATER, or EQUAL depending on how  string  compares with
+ * string2 (s1 ??? s2).
+ *
+ * 	o Matches up to len(s1) are EQUAL.
+ *	o Matches up to len(s2) are GREATER.
+ *
+ * Compare understands about the -f and -d flags, and treats comparisons
+ * appropriately.
+ *
+ * The string "string" is null terminated.  The string "s2" is '\n' terminated
+ * (or "s2end" terminated).
+ *
+ * We use strcasecmp etc, since it knows how to ignore case also
+ * in other locales.
+ */
+static int
+compare(char *s2, char *s2end) {
+	int i;
+	char *p;
+
+	/* copy, ignoring things that should be ignored */
+	p = comparbuf;
+	i = stringlen;
+	while(s2 < s2end && *s2 != '\n' && i) {
+		if (!dflag || isalnum(*s2) || isblank(*s2))
+		{
+			*p++ = *s2;
+			i--;
+		}
+		s2++;
+	}
+	*p = 0;
+
+	/* and compare */
+	if (fflag)
+		i = strncasecmp(comparbuf, string, stringlen);
+	else
+		i = strncmp(comparbuf, string, stringlen);
+
+	return ((i > 0) ? LESS : (i < 0) ? GREATER : EQUAL);
+}
+
+static void __attribute__((__noreturn__)) usage(void)
+{
+	FILE *out = stdout;
+	fputs(USAGE_HEADER, out);
+	fprintf(out, _(" %s [options] <string> [<file>...]\n"), program_invocation_short_name);
+
+	fputs(USAGE_SEPARATOR, out);
+	fputs(_("Display lines beginning with a specified string.\n"), out);
+
+	fputs(USAGE_OPTIONS, out);
+	fputs(_(" -a, --alternative        use the alternative dictionary\n"), out);
+	fputs(_(" -d, --alphanum           compare only blanks and alphanumeric characters\n"), out);
+	fputs(_(" -f, --ignore-case        ignore case differences when comparing\n"), out);
+	fputs(_(" -t, --terminate <char>   define the string-termination character\n"), out);
+
+	fputs(USAGE_SEPARATOR, out);
+	printf(USAGE_HELP_OPTIONS(26));
+	printf(USAGE_MAN_TAIL("look(1)"));
+
+	exit(EXIT_SUCCESS);
+}