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-rw-r--r--usr.bin/tail/tail.c338
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diff --git a/usr.bin/tail/tail.c b/usr.bin/tail/tail.c
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+/*-
+ * Copyright (c) 1991, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Edward Sze-Tyan Wang.
+ *
+ * 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.
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+
+__FBSDID("$FreeBSD$");
+
+#ifndef lint
+static const char copyright[] =
+"@(#) Copyright (c) 1991, 1993\n\
+ The Regents of the University of California. All rights reserved.\n";
+#endif
+
+#ifndef lint
+static const char sccsid[] = "@(#)tail.c 8.1 (Berkeley) 6/6/93";
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "extern.h"
+
+int Fflag, fflag, qflag, rflag, rval, no_files;
+
+static file_info_t *files;
+
+static void obsolete(char **);
+static void usage(void);
+
+int
+main(int argc, char *argv[])
+{
+ struct stat sb;
+ const char *fn;
+ FILE *fp;
+ off_t off;
+ enum STYLE style;
+ int i, ch, first;
+ file_info_t *file;
+ char *p;
+
+ /*
+ * Tail's options are weird. First, -n10 is the same as -n-10, not
+ * -n+10. Second, the number options are 1 based and not offsets,
+ * so -n+1 is the first line, and -c-1 is the last byte. Third, the
+ * number options for the -r option specify the number of things that
+ * get displayed, not the starting point in the file. The one major
+ * incompatibility in this version as compared to historical versions
+ * is that the 'r' option couldn't be modified by the -lbc options,
+ * i.e. it was always done in lines. This version treats -rc as a
+ * number of characters in reverse order. Finally, the default for
+ * -r is the entire file, not 10 lines.
+ */
+#define ARG(units, forward, backward) { \
+ if (style) \
+ usage(); \
+ off = strtoll(optarg, &p, 10) * (units); \
+ if (*p) \
+ errx(1, "illegal offset -- %s", optarg); \
+ switch(optarg[0]) { \
+ case '+': \
+ if (off) \
+ off -= (units); \
+ style = (forward); \
+ break; \
+ case '-': \
+ off = -off; \
+ /* FALLTHROUGH */ \
+ default: \
+ style = (backward); \
+ break; \
+ } \
+}
+
+ obsolete(argv);
+ style = NOTSET;
+ off = 0;
+ while ((ch = getopt(argc, argv, "Fb:c:fn:qr")) != -1)
+ switch(ch) {
+ case 'F': /* -F is superset of (and implies) -f */
+ Fflag = fflag = 1;
+ break;
+ case 'b':
+ ARG(512, FBYTES, RBYTES);
+ break;
+ case 'c':
+ ARG(1, FBYTES, RBYTES);
+ break;
+ case 'f':
+ fflag = 1;
+ break;
+ case 'n':
+ ARG(1, FLINES, RLINES);
+ break;
+ case 'q':
+ qflag = 1;
+ break;
+ case 'r':
+ rflag = 1;
+ break;
+ case '?':
+ default:
+ usage();
+ }
+ argc -= optind;
+ argv += optind;
+
+ no_files = argc ? argc : 1;
+
+ /*
+ * If displaying in reverse, don't permit follow option, and convert
+ * style values.
+ */
+ if (rflag) {
+ if (fflag)
+ usage();
+ if (style == FBYTES)
+ style = RBYTES;
+ else if (style == FLINES)
+ style = RLINES;
+ }
+
+ /*
+ * If style not specified, the default is the whole file for -r, and
+ * the last 10 lines if not -r.
+ */
+ if (style == NOTSET) {
+ if (rflag) {
+ off = 0;
+ style = REVERSE;
+ } else {
+ off = 10;
+ style = RLINES;
+ }
+ }
+
+ if (*argv && fflag) {
+ files = (struct file_info *) malloc(no_files *
+ sizeof(struct file_info));
+ if (!files)
+ err(1, "Couldn't malloc space for file descriptors.");
+
+ for (file = files; (fn = *argv++); file++) {
+ file->file_name = strdup(fn);
+ if (! file->file_name)
+ errx(1, "Couldn't malloc space for file name.");
+ if ((file->fp = fopen(file->file_name, "r")) == NULL ||
+ fstat(fileno(file->fp), &file->st)) {
+ if (file->fp != NULL) {
+ fclose(file->fp);
+ file->fp = NULL;
+ }
+ if (!Fflag || errno != ENOENT)
+ ierr(file->file_name);
+ }
+ }
+ follow(files, style, off);
+ for (i = 0, file = files; i < no_files; i++, file++) {
+ free(file->file_name);
+ }
+ free(files);
+ } else if (*argv) {
+ for (first = 1; (fn = *argv++);) {
+ if ((fp = fopen(fn, "r")) == NULL ||
+ fstat(fileno(fp), &sb)) {
+ ierr(fn);
+ continue;
+ }
+ if (argc > 1 && !qflag) {
+ (void)printf("%s==> %s <==\n",
+ first ? "" : "\n", fn);
+ first = 0;
+ (void)fflush(stdout);
+ }
+
+ if (rflag)
+ reverse(fp, fn, style, off, &sb);
+ else
+ forward(fp, fn, style, off, &sb);
+ }
+ } else {
+ fn = "stdin";
+
+ if (fstat(fileno(stdin), &sb)) {
+ ierr(fn);
+ exit(1);
+ }
+
+ /*
+ * Determine if input is a pipe. 4.4BSD will set the SOCKET
+ * bit in the st_mode field for pipes. Fix this then.
+ */
+ if (lseek(fileno(stdin), (off_t)0, SEEK_CUR) == -1 &&
+ errno == ESPIPE) {
+ errno = 0;
+ fflag = 0; /* POSIX.2 requires this. */
+ }
+
+ if (rflag)
+ reverse(stdin, fn, style, off, &sb);
+ else
+ forward(stdin, fn, style, off, &sb);
+ }
+ exit(rval);
+}
+
+/*
+ * Convert the obsolete argument form into something that getopt can handle.
+ * This means that anything of the form [+-][0-9][0-9]*[lbc][Ffr] that isn't
+ * the option argument for a -b, -c or -n option gets converted.
+ */
+static void
+obsolete(char *argv[])
+{
+ char *ap, *p, *t;
+ size_t len;
+ char *start;
+
+ while ((ap = *++argv)) {
+ /* Return if "--" or not an option of any form. */
+ if (ap[0] != '-') {
+ if (ap[0] != '+')
+ return;
+ } else if (ap[1] == '-')
+ return;
+
+ switch(*++ap) {
+ /* Old-style option. */
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+
+ /* Malloc space for dash, new option and argument. */
+ len = strlen(*argv);
+ if ((start = p = malloc(len + 3)) == NULL)
+ err(1, "malloc");
+ *p++ = '-';
+
+ /*
+ * Go to the end of the option argument. Save off any
+ * trailing options (-3lf) and translate any trailing
+ * output style characters.
+ */
+ t = *argv + len - 1;
+ if (*t == 'F' || *t == 'f' || *t == 'r') {
+ *p++ = *t;
+ *t-- = '\0';
+ }
+ switch(*t) {
+ case 'b':
+ *p++ = 'b';
+ *t = '\0';
+ break;
+ case 'c':
+ *p++ = 'c';
+ *t = '\0';
+ break;
+ case 'l':
+ *t = '\0';
+ /* FALLTHROUGH */
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ *p++ = 'n';
+ break;
+ default:
+ errx(1, "illegal option -- %s", *argv);
+ }
+ *p++ = *argv[0];
+ (void)strcpy(p, ap);
+ *argv = start;
+ continue;
+
+ /*
+ * Options w/ arguments, skip the argument and continue
+ * with the next option.
+ */
+ case 'b':
+ case 'c':
+ case 'n':
+ if (!ap[1])
+ ++argv;
+ /* FALLTHROUGH */
+ /* Options w/o arguments, continue with the next option. */
+ case 'F':
+ case 'f':
+ case 'r':
+ continue;
+
+ /* Illegal option, return and let getopt handle it. */
+ default:
+ return;
+ }
+ }
+}
+
+static void
+usage(void)
+{
+ (void)fprintf(stderr,
+ "usage: tail [-F | -f | -r] [-q] [-b # | -c # | -n #]"
+ " [file ...]\n");
+ exit(1);
+}
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