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-rw-r--r--inotail-old.c389
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diff --git a/inotail-old.c b/inotail-old.c
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+++ b/inotail-old.c
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+/*
+ * inotail.c
+ * A fast implementation of GNU tail which uses the inotify-API present in
+ * recent Linux Kernels.
+ *
+ * Copyright (C) 2005-2006, Tobias Klauser <tklauser@distanz.ch>
+ *
+ * Parts of this program are based on GNU tail included in the GNU coreutils
+ * which is:
+ * Copyright (C) 1989, 90, 91, 1995-2005 Free Software Foundation, Inc.
+ *
+ * The idea and some code were taken from turbotail.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+
+#include "inotify.h"
+#include "inotify-syscalls.h"
+
+#include "inotail.h"
+
+#define VERSION "0.1"
+
+/* XXX: Move all global variables into a struct and use :1 */
+
+/* If !=0, read from the ends of all specified files until killed. */
+static unsigned short forever;
+
+/* Print header with filename before tailing the file? */
+static unsigned short print_headers = 0;
+
+/* Say my name! */
+static char *program_name = "inotail";
+
+static int dump_remainder(const char *filename, int fd, ssize_t n_bytes)
+{
+ ssize_t written = 0;
+
+ dprintf("==> dump_remainder()\n");
+
+ if (n_bytes > SSIZE_MAX)
+ n_bytes = SSIZE_MAX;
+
+ return written;
+}
+
+static char *pretty_name(const struct file_struct *f)
+{
+ return ((strcmp(f->name, "-") == 0) ? "standard input" : f->name);
+}
+
+static void write_header(const struct file_struct *f)
+{
+ static unsigned short first_file = 1;
+
+ fprintf (stdout, "%s==> %s <==\n", (first_file ? "" : "\n"), pretty_name(f));
+ first_file = 0;
+}
+
+static int file_lines(struct file_struct *f, uintmax_t n_lines, off_t start_pos, off_t end_pos)
+{
+ char buffer[BUFSIZ];
+ size_t bytes_read;
+ off_t pos = end_pos;
+
+ dprintf("==> file_lines()\n");
+
+ if (n_lines == 0)
+ return 1;
+
+ dprintf(" start_pos: %lld\n", (unsigned long long) start_pos);
+ dprintf(" end_pos: %lld\n", (unsigned long long) end_pos);
+
+ /* Set `bytes_read' to the size of the last, probably partial, buffer;
+ * 0 < `bytes_read' <= `BUFSIZ'.
+ */
+ bytes_read = (pos - start_pos) % BUFSIZ;
+ if (bytes_read == 0)
+ bytes_read = BUFSIZ;
+
+ dprintf(" bytes_read: %zd\n", bytes_read);
+
+ /* Make `pos' a multiple of `BUFSIZ' (0 if the file is short), so that
+ * all
+ * reads will be on block boundaries, which might increase
+ * efficiency. */
+ pos -= bytes_read;
+
+ dprintf(" pos: %lld\n", pos);
+
+ lseek(f->fd, pos, SEEK_SET);
+ bytes_read = read(f->fd, buffer, bytes_read);
+
+ /* Count the incomplete line on files that don't end with a newline. */
+ if (bytes_read && buffer[bytes_read - 1] != '\n')
+ --n_lines;
+
+ do {
+ size_t n = bytes_read;
+ while (n) {
+ const char *nl;
+ nl = memrchr(buffer, '\n', n);
+ if (nl == NULL)
+ break;
+ }
+
+ /* XXX XXX XXX XXX */
+
+ /* Not enough newlines in that buffer. Just print everything */
+ if (pos == start_pos) {
+ lseek(f->fd, start_pos, SEEK_SET);
+ return 1;
+ }
+ pos -= BUFSIZ;
+ } while (bytes_read > 0);
+
+ return 1;
+}
+
+static void check_file(struct file_struct *f)
+{
+ struct stat new_stats;
+
+ dprintf("==> check_file()\n");
+
+ dprintf(" checking '%s'\n", f->name);
+}
+
+static int tail_forever(struct file_struct *f, int n_files)
+{
+ int i_fd, len;
+ unsigned int i;
+ struct inotify_event *inev;
+ char buf[1000];
+
+ dprintf("==> tail_forever()\n");
+
+ i_fd = inotify_init();
+ if (i_fd < 0)
+ return -1;
+
+ for (i = 0; i < n_files; i++) {
+ f[i].i_watch = inotify_add_watch(i_fd, f[i].name, IN_ALL_EVENTS | IN_UNMOUNT);
+ dprintf(" Watch (%d) added to '%s' (%d)\n", f[i].i_watch, f[i].name, i);
+ }
+
+ memset(&buf, 0, sizeof(buf));
+
+ while (1) {
+ int fd;
+ ssize_t bytes_tailed = 0;
+
+ len = read(i_fd, buf, sizeof(buf));
+ inev = (struct inotify_event *) &buf;
+
+ while (len > 0) {
+ struct file_struct *fil;
+
+ /* Which file has produced the event? */
+ for (i = 0; i < n_files; i++) {
+ if (!f[i].ignore && f[i].fd >= 0 && f[i].i_watch == inev->wd) {
+ fil = &f[i];
+ break;
+ }
+ }
+
+ /* We should at least catch the following
+ * events:
+ * - IN_MODIFY, thats what we hopefully get
+ * most of the time
+ * - IN_ATTRIB, still readable?
+ * - IN_MOVE, reopen the file at the new
+ * position?
+ * - IN_DELETE_SELF, we need to check if the
+ * file is still there or is really gone
+ * - IN_MOVE_SELF, ditto
+ * - IN_UNMOUNT, die gracefully
+ */
+ if (inev->mask & IN_MODIFY) {
+ dprintf(" File '%s' modified.\n", fil->name);
+ check_file(fil);
+ /* Dump new content */
+ } else if (inev->mask & IN_ATTRIB) {
+ dprintf(" File '%s' attributes changed.\n", fil->name);
+ check_file(fil);
+ } else if (inev->mask & IN_MOVE) {
+ } else if (inev->mask & IN_DELETE_SELF) {
+ dprintf(" File '%s' possibly deleted.\n", fil->name);
+ check_file(fil);
+ } else {
+ /* Ignore */
+ }
+
+ /* Shift one event forward */
+ len -= sizeof(struct inotify_event) + inev->len;
+ inev = (struct inotify_event *) ((char *) inev + sizeof(struct inotify_event) + inev->len);
+ }
+ }
+
+ /* XXX: Never reached. Catch SIGINT and handle it there? */
+ for (i = 0; i < n_files; i++)
+ inotify_rm_watch(i_fd, f[i].i_watch);
+
+ return 0;
+}
+
+static int tail_lines(struct file_struct *f, uintmax_t n_lines)
+{
+ struct stat stats;
+ off_t start_pos = -1;
+ off_t end_pos;
+
+ dprintf("==> tail_lines()\n");
+
+ if (fstat(f->fd, &stats)) {
+ perror("fstat()");
+ exit(EXIT_FAILURE);
+ }
+
+ start_pos = lseek(f->fd, 0, SEEK_CUR);
+ end_pos = lseek(f->fd, 0, SEEK_END);
+
+ /* Use file_lines only if FD refers to a regular file for
+ * which lseek(... SEEK_END) worked.
+ */
+ if (S_ISREG(stats.st_mode) && start_pos != -1 && start_pos < end_pos) {
+ if (end_pos != 0 && !file_lines(f, n_lines, start_pos, end_pos))
+ return -1;
+ } else {
+ /* Under very unlikely circumstances, it is possible to reach
+ this point after positioning the file pointer to end of file
+ via the `lseek (...SEEK_END)' above. In that case, reposition
+ the file pointer back to start_pos before calling pipe_lines. */
+/* if (start_pos != -1)
+ xlseek (fd, start_pos, SEEK_SET, pretty_filename);
+
+ return pipe_lines (pretty_filename, fd, n_lines, read_pos);
+*/
+ }
+
+ return 0;
+}
+
+static int tail(struct file_struct *f, uintmax_t n_units)
+{
+ dprintf("==> tail()\n");
+
+ return tail_lines(f, n_units);
+}
+
+static int tail_file(struct file_struct *f, uintmax_t n_units)
+{
+ int ret = 0;
+
+ dprintf("==> tail_file()\n");
+
+ if (strcmp(f->name, "-") == 0) {
+ f->fd = STDIN_FILENO;
+ } else {
+ f->fd = open(f->name, O_RDONLY);
+ }
+
+ if (f->fd == -1) {
+ perror("open()");
+ } else {
+ if (print_headers)
+ write_header(f);
+ ret = tail(f, n_units);
+ }
+
+ return ret;
+}
+
+static void usage(void)
+{
+ dprintf("==> usage()\n");
+
+ fprintf(stderr, "Usage: %s [OPTION]... [FILE]...\n", program_name);
+}
+
+static void parse_options(int argc, char *argv[], int *n_lines)
+{
+ int c;
+
+ dprintf("==> parse_options()\n");
+
+ while ((c = getopt_long(argc, argv, "hfn:qvV", long_options, NULL)) != -1) {
+ switch (c) {
+ case 'f':
+ forever = 1;
+ break;
+ case 'n':
+ *n_lines = strtol(optarg, NULL, 0);
+ if (*n_lines < 0)
+ *n_lines = 0;
+ break;
+ case 'q':
+ print_headers = 0;
+ break;
+ case 'v':
+ print_headers = 1;
+ break;
+ case 'V':
+ fprintf(stdout, "%s %s by Tobias Klauser <tklauser@distanz.ch>\n",
+ program_name, VERSION);
+ break;
+ case 'h':
+ default:
+ usage();
+ }
+ }
+}
+
+int main(int argc, char *argv[])
+{
+ int n_files = 0;
+ int n_lines = DEFAULT_N_LINES;
+ struct file_struct *files;
+ char **filenames;
+ unsigned int i;
+
+ parse_options(argc, argv, &n_lines);
+
+ /* Do we have some files to read from? */
+ if (optind < argc) {
+ n_files = argc - optind;
+ filenames = argv + optind;
+ } else { /* OK, we read from stdin */
+ static char *dummy_stdin = "-";
+
+ n_files = 1;
+ filenames = &dummy_stdin;
+
+ /*
+ * POSIX says that -f is ignored if no file operand is specified
+ * and standard input is a pipe.
+ */
+ if (forever) {
+ struct stat stats;
+ /* stdin might be a socket on some systems */
+ if ((fstat(STDIN_FILENO, &stats) == 0)
+ && (S_ISFIFO(stats.st_mode) || S_ISSOCK(stats.st_mode)))
+ forever = 0;
+ }
+
+ fprintf(stderr, "Reading from stdin is currently not supported.\n");
+ }
+
+ files = malloc(n_files * sizeof(struct file_struct));
+ for (i = 0; i < n_files; i++) {
+ files[i].name = filenames[i];
+ tail_file(&files[i], n_lines);
+ }
+
+ if (forever)
+ tail_forever(files, n_files);
+
+ free(files);
+
+ exit(EXIT_SUCCESS);
+}
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-11-22 13:38:50 +0000