+/* vi: set sw=4 ts=4: */
+#include "internal.h"
+
+/* This file contains _two_ implementations of tail. One is
+ * a bit more full featured, but costs 6k. The other (i.e. the
+ * SIMPLE_TAIL one) is less capable, but is good enough for about
+ * 99% of the things folks want to use tail for, and only costs 2k.
+ */
+
+
+#ifdef BB_FEATURE_SIMPLE_TAIL
+
+/* tail -- output the last part of file(s)
+ Copyright (C) 89, 90, 91, 95, 1996 Free Software Foundation, Inc.
+
+ 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+ Original version by Paul Rubin <phr@ocf.berkeley.edu>.
+ Extensions by David MacKenzie <djm@gnu.ai.mit.edu>.
+ tail -f for multiple files by Ian Lance Taylor <ian@airs.com>.
+
+ Rewrote the option parser, removed locales support,
+ and generally busyboxed, Erik Andersen <andersen@lineo.com>
+
+ Removed superfluous options and associated code ("-c", "-n", "-q").
+ Removed "tail -f" support for multiple files.
+ Both changes by Friedrich Vedder <fwv@myrtle.lahn.de>.
+
+ */
+
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <ctype.h>
+#define BB_DECLARE_EXTERN
+#define bb_need_help
+#include "messages.c"
+
+
+#define XWRITE(fd, buffer, n_bytes) \
+ do { \
+ if (n_bytes > 0 && fwrite ((buffer), 1, (n_bytes), stdout) == 0) \
+ errorMsg("write error"); \
+ } while (0)
+
+/* Number of items to tail. */
+#define DEFAULT_N_LINES 10
+
+/* Size of atomic reads. */
+#ifndef BUFSIZ
+#define BUFSIZ (512 * 8)
+#endif
+
+/* If nonzero, read from the end of one file until killed. */
+static int forever;
+
+/* If nonzero, print filename headers. */
+static int print_headers;
+
+const char tail_usage[] =
+ "tail [OPTION] [FILE]...\n"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+ "\nPrint last 10 lines of each FILE to standard output.\n"
+ "With more than one FILE, precede each with a header giving the\n"
+ "file name. With no FILE, or when FILE is -, read standard input.\n\n"
+ "Options:\n"
+ "\t-n NUM\t\tPrint last NUM lines instead of first 10\n"
+
+ "\t-f\t\tOutput data as the file grows. This version\n"
+ "\t\t\tof 'tail -f' supports only one file at a time.\n"
+#endif
+ ;
+
+
+static void write_header(const char *filename)
+{
+ static int first_file = 1;
+
+ printf("%s==> %s <==\n", (first_file ? "" : "\n"), filename);
+ first_file = 0;
+}
+
+/* Print the last N_LINES lines from the end of file FD.
+ Go backward through the file, reading `BUFSIZ' bytes at a time (except
+ probably the first), until we hit the start of the file or have
+ read NUMBER newlines.
+ POS starts out as the length of the file (the offset of the last
+ byte of the file + 1).
+ Return 0 if successful, 1 if an error occurred. */
+
+static int
+file_lines(const char *filename, int fd, long int n_lines, off_t pos)
+{
+ char buffer[BUFSIZ];
+ int bytes_read;
+ int i; /* Index into `buffer' for scanning. */
+
+ if (n_lines == 0)
+ return 0;
+
+ /* Set `bytes_read' to the size of the last, probably partial, buffer;
+ 0 < `bytes_read' <= `BUFSIZ'. */
+ bytes_read = pos % BUFSIZ;
+ if (bytes_read == 0)
+ bytes_read = BUFSIZ;
+ /* 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;
+ lseek(fd, pos, SEEK_SET);
+ bytes_read = fullRead(fd, buffer, bytes_read);
+ if (bytes_read == -1)
+ errorMsg("read error");
+
+ /* Count the incomplete line on files that don't end with a newline. */
+ if (bytes_read && buffer[bytes_read - 1] != '\n')
+ --n_lines;
+
+ do {
+ /* Scan backward, counting the newlines in this bufferfull. */
+ for (i = bytes_read - 1; i >= 0; i--) {
+ /* Have we counted the requested number of newlines yet? */
+ if (buffer[i] == '\n' && n_lines-- == 0) {
+ /* If this newline wasn't the last character in the buffer,
+ print the text after it. */
+ if (i != bytes_read - 1)
+ XWRITE(STDOUT_FILENO, &buffer[i + 1],
+ bytes_read - (i + 1));
+ return 0;
+ }
+ }
+ /* Not enough newlines in that bufferfull. */
+ if (pos == 0) {
+ /* Not enough lines in the file; print the entire file. */
+ lseek(fd, (off_t) 0, SEEK_SET);
+ return 0;
+ }
+ pos -= BUFSIZ;
+ lseek(fd, pos, SEEK_SET);
+ }
+ while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0);
+ if (bytes_read == -1)
+ errorMsg("read error");
+
+ return 0;
+}
+
+/* Print the last N_LINES lines from the end of the standard input,
+ open for reading as pipe FD.
+ Buffer the text as a linked list of LBUFFERs, adding them as needed.
+ Return 0 if successful, 1 if an error occured. */
+
+static int pipe_lines(const char *filename, int fd, long int n_lines)
+{
+ struct linebuffer {
+ int nbytes, nlines;
+ char buffer[BUFSIZ];
+ struct linebuffer *next;
+ };
+ typedef struct linebuffer LBUFFER;
+ LBUFFER *first, *last, *tmp;
+ int i; /* Index into buffers. */
+ int total_lines = 0; /* Total number of newlines in all buffers. */
+ int errors = 0;
+
+ first = last = (LBUFFER *) xmalloc(sizeof(LBUFFER));
+ first->nbytes = first->nlines = 0;
+ first->next = NULL;
+ tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER));
+
+ /* Input is always read into a fresh buffer. */
+ while ((tmp->nbytes = fullRead(fd, tmp->buffer, BUFSIZ)) > 0) {
+ tmp->nlines = 0;
+ tmp->next = NULL;
+
+ /* Count the number of newlines just read. */
+ for (i = 0; i < tmp->nbytes; i++)
+ if (tmp->buffer[i] == '\n')
+ ++tmp->nlines;
+ total_lines += tmp->nlines;
+
+ /* If there is enough room in the last buffer read, just append the new
+ one to it. This is because when reading from a pipe, `nbytes' can
+ often be very small. */
+ if (tmp->nbytes + last->nbytes < BUFSIZ) {
+ memcpy(&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes);
+ last->nbytes += tmp->nbytes;
+ last->nlines += tmp->nlines;
+ } else {
+ /* If there's not enough room, link the new buffer onto the end of
+ the list, then either free up the oldest buffer for the next
+ read if that would leave enough lines, or else malloc a new one.
+ Some compaction mechanism is possible but probably not
+ worthwhile. */
+ last = last->next = tmp;
+ if (total_lines - first->nlines > n_lines) {
+ tmp = first;
+ total_lines -= first->nlines;
+ first = first->next;
+ } else
+ tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER));
+ }
+ }
+ if (tmp->nbytes == -1)
+ errorMsg("read error");
+
+ free((char *) tmp);
+
+ /* This prevents a core dump when the pipe contains no newlines. */
+ if (n_lines == 0)
+ goto free_lbuffers;
+
+ /* Count the incomplete line on files that don't end with a newline. */
+ if (last->buffer[last->nbytes - 1] != '\n') {
+ ++last->nlines;
+ ++total_lines;
+ }
+
+ /* Run through the list, printing lines. First, skip over unneeded
+ buffers. */
+ for (tmp = first; total_lines - tmp->nlines > n_lines; tmp = tmp->next)
+ total_lines -= tmp->nlines;
+
+ /* Find the correct beginning, then print the rest of the file. */
+ if (total_lines > n_lines) {
+ char *cp;
+
+ /* Skip `total_lines' - `n_lines' newlines. We made sure that
+ `total_lines' - `n_lines' <= `tmp->nlines'. */
+ cp = tmp->buffer;
+ for (i = total_lines - n_lines; i; --i)
+ while (*cp++ != '\n')
+ /* Do nothing. */ ;
+ i = cp - tmp->buffer;
+ } else
+ i = 0;
+ XWRITE(STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i);
+
+ for (tmp = tmp->next; tmp; tmp = tmp->next)
+ XWRITE(STDOUT_FILENO, tmp->buffer, tmp->nbytes);
+
+ free_lbuffers:
+ while (first) {
+ tmp = first->next;
+ free((char *) first);
+ first = tmp;
+ }
+ return errors;
+}
+
+/* Display file FILENAME from the current position in FD to the end.
+ If `forever' is nonzero, keep reading from the end of the file
+ until killed. Return the number of bytes read from the file. */
+
+static long dump_remainder(const char *filename, int fd)
+{
+ char buffer[BUFSIZ];
+ int bytes_read;
+ long total;
+
+ total = 0;
+ output:
+ while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0) {
+ XWRITE(STDOUT_FILENO, buffer, bytes_read);
+ total += bytes_read;
+ }
+ if (bytes_read == -1)
+ errorMsg("read error");
+ if (forever) {
+ fflush(stdout);
+ sleep(1);
+ goto output;
+ }
+
+ return total;
+}
+
+/* Output the last N_LINES lines of file FILENAME open for reading in FD.
+ Return 0 if successful, 1 if an error occurred. */
+
+static int tail_lines(const char *filename, int fd, long int n_lines)
+{
+ struct stat stats;
+ off_t length;
+
+ if (print_headers)
+ write_header(filename);
+
+ if (fstat(fd, &stats))
+ errorMsg("fstat error");
+
+ /* Use file_lines only if FD refers to a regular file with
+ its file pointer positioned at beginning of file. */
+ /* FIXME: adding the lseek conjunct is a kludge.
+ Once there's a reasonable test suite, fix the true culprit:
+ file_lines. file_lines shouldn't presume that the input
+ file pointer is initially positioned to beginning of file. */
+ if (S_ISREG(stats.st_mode)
+ && lseek(fd, (off_t) 0, SEEK_CUR) == (off_t) 0) {
+ length = lseek(fd, (off_t) 0, SEEK_END);
+ if (length != 0 && file_lines(filename, fd, n_lines, length))
+ return 1;
+ dump_remainder(filename, fd);
+ } else
+ return pipe_lines(filename, fd, n_lines);
+
+ return 0;
+}
+
+/* Display the last N_UNITS lines of file FILENAME.
+ "-" for FILENAME means the standard input.
+ Return 0 if successful, 1 if an error occurred. */
+
+static int tail_file(const char *filename, off_t n_units)
+{
+ int fd, errors;
+
+ if (!strcmp(filename, "-")) {
+ filename = "standard input";
+ errors = tail_lines(filename, 0, (long) n_units);
+ } else {
+ /* Not standard input. */
+ fd = open(filename, O_RDONLY);
+ if (fd == -1)
+ perror(filename);
+
+ errors = tail_lines(filename, fd, (long) n_units);
+ close(fd);
+ }
+
+ return errors;
+}
+
+extern int tail_main(int argc, char **argv)
+{
+ int exit_status = 0;
+ int n_units = DEFAULT_N_LINES;
+ int n_tmp, i;
+ char opt;
+
+ forever = print_headers = 0;
+
+ /* parse argv[] */
+ for (i = 1; i < argc; i++) {
+ if (argv[i][0] == '-') {
+ opt = argv[i][1];
+ switch (opt) {
+ case 'f':
+ forever = 1;
+ break;
+ case 'n':
+ n_tmp = 0;
+ if (++i < argc)
+ n_tmp = atoi(argv[i]);
+ if (n_tmp < 1)
+ usage(tail_usage);
+ n_units = n_tmp;
+ break;
+ case '-':
+ case 'h':
+ usage(tail_usage);
+ default:
+ if ((n_units = atoi(&argv[i][1])) < 1) {
+ fprintf(stderr, "tail: invalid option -- %c\n", opt);
+ usage(tail_usage);
+ }
+ }
+ } else {
+ break;
+ }
+ }
+
+ if (i + 1 < argc) {
+ if (forever) {
+ fprintf(stderr,
+ "tail: option -f is invalid with multiple files\n");
+ usage(tail_usage);
+ }
+ print_headers = 1;
+ }
+
+ if (i >= argc) {
+ exit_status |= tail_file("-", n_units);
+ } else {
+ for (; i < argc; i++)
+ exit_status |= tail_file(argv[i], n_units);
+ }
+
+ return(exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+}
+
+
+#else
+// Here follows the code for the full featured tail code
+
+
/* tail -- output the last part of file(s)
Copyright (C) 89, 90, 91, 95, 1996 Free Software Foundation, Inc.
#define NDEBUG 1
-static void error(int i, int errnum, char* fmt, ...)
+static void detailed_error(int i, int errnum, char *fmt, ...)
+ __attribute__ ((format (printf, 3, 4)));
+static void detailed_error(int i, int errnum, char *fmt, ...)
{
- va_list arguments;
+ va_list arguments;
- va_start(arguments, fmt);
- vfprintf(stderr, fmt, arguments);
- fprintf(stderr, "\n%s\n", strerror( errnum));
- va_end(arguments);
- exit(i);
+ va_start(arguments, fmt);
+ vfprintf(stderr, fmt, arguments);
+ fprintf(stderr, "\n%s\n", strerror(errnum));
+ va_end(arguments);
+ exit(i);
}
assert ((fd) == 1); \
assert ((n_bytes) >= 0); \
if (n_bytes > 0 && fwrite ((buffer), 1, (n_bytes), stdout) == 0) \
- error (EXIT_FAILURE, errno, "write error"); \
+ detailed_error (EXIT_FAILURE, errno, "write error"); \
} \
while (0)
static int print_headers;
/* When to print the filename banners. */
-enum header_mode
-{
- multiple_files, always, never
+enum header_mode {
+ multiple_files, always, never
};
-char *xmalloc ();
-
/* The name this program was run with. */
char *program_name;
static int have_read_stdin;
-static const char tail_usage[] =
-"tail [OPTION]... [FILE]...\n\
-\n\
-Print last 10 lines of each FILE to standard output.\n\
+static const char tail_usage[] = "tail [OPTION]... [FILE]...\n"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+"\nPrint last 10 lines of each FILE to standard output.\n\
With more than one FILE, precede each with a header giving the file name.\n\
With no FILE, or when FILE is -, read standard input.\n\
\n\
-n=N output the last N lines, instead of last 10\n\
-q never output headers giving file names\n\
-v always output headers giving file names\n\
- --help display this help and exit\n\
\n\
If the first character of N (bytes or lines) is a `+', output begins with \n\
the Nth item from the start of each file, otherwise, print the last N items\n\
-in the file. N bytes may be suffixed by k (x1024), b (x512), or m (1024^2).\n\n";
+in the file. N bytes may be suffixed by k (x1024), b (x512), or m (1024^2).\n"
+#endif
+;
-static void
-write_header (const char *filename, const char *comment)
+static void write_header(const char *filename, const char *comment)
{
- static int first_file = 1;
+ static int first_file = 1;
- printf ("%s==> %s%s%s <==\n", (first_file ? "" : "\n"), filename,
- (comment ? ": " : ""),
- (comment ? comment : ""));
- first_file = 0;
+ printf("%s==> %s%s%s <==\n", (first_file ? "" : "\n"), filename,
+ (comment ? ": " : ""), (comment ? comment : ""));
+ first_file = 0;
}
/* Print the last N_LINES lines from the end of file FD.
Return 0 if successful, 1 if an error occurred. */
static int
-file_lines (const char *filename, int fd, long int n_lines, off_t pos)
+file_lines(const char *filename, int fd, long int n_lines, off_t pos)
{
- char buffer[BUFSIZ];
- int bytes_read;
- int i; /* Index into `buffer' for scanning. */
-
- if (n_lines == 0)
- return 0;
-
- /* Set `bytes_read' to the size of the last, probably partial, buffer;
- 0 < `bytes_read' <= `BUFSIZ'. */
- bytes_read = pos % BUFSIZ;
- if (bytes_read == 0)
- bytes_read = BUFSIZ;
- /* 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;
- lseek (fd, pos, SEEK_SET);
- bytes_read = fullRead (fd, buffer, bytes_read);
- if (bytes_read == -1)
- {
- error (0, errno, "%s", filename);
- return 1;
- }
-
- /* Count the incomplete line on files that don't end with a newline. */
- if (bytes_read && buffer[bytes_read - 1] != '\n')
- --n_lines;
-
- do
- {
- /* Scan backward, counting the newlines in this bufferfull. */
- for (i = bytes_read - 1; i >= 0; i--)
- {
- /* Have we counted the requested number of newlines yet? */
- if (buffer[i] == '\n' && n_lines-- == 0)
- {
- /* If this newline wasn't the last character in the buffer,
- print the text after it. */
- if (i != bytes_read - 1)
- XWRITE (STDOUT_FILENO, &buffer[i + 1], bytes_read - (i + 1));
- return 0;
- }
- }
- /* Not enough newlines in that bufferfull. */
- if (pos == 0)
- {
- /* Not enough lines in the file; print the entire file. */
- lseek (fd, (off_t) 0, SEEK_SET);
- return 0;
- }
- pos -= BUFSIZ;
- lseek (fd, pos, SEEK_SET);
- }
- while ((bytes_read = fullRead (fd, buffer, BUFSIZ)) > 0);
- if (bytes_read == -1)
- {
- error (0, errno, "%s", filename);
- return 1;
- }
- return 0;
+ char buffer[BUFSIZ];
+ int bytes_read;
+ int i; /* Index into `buffer' for scanning. */
+
+ if (n_lines == 0)
+ return 0;
+
+ /* Set `bytes_read' to the size of the last, probably partial, buffer;
+ 0 < `bytes_read' <= `BUFSIZ'. */
+ bytes_read = pos % BUFSIZ;
+ if (bytes_read == 0)
+ bytes_read = BUFSIZ;
+ /* 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;
+ lseek(fd, pos, SEEK_SET);
+ bytes_read = fullRead(fd, buffer, bytes_read);
+ if (bytes_read == -1) {
+ detailed_error(0, errno, "%s", filename);
+ return 1;
+ }
+
+ /* Count the incomplete line on files that don't end with a newline. */
+ if (bytes_read && buffer[bytes_read - 1] != '\n')
+ --n_lines;
+
+ do {
+ /* Scan backward, counting the newlines in this bufferfull. */
+ for (i = bytes_read - 1; i >= 0; i--) {
+ /* Have we counted the requested number of newlines yet? */
+ if (buffer[i] == '\n' && n_lines-- == 0) {
+ /* If this newline wasn't the last character in the buffer,
+ print the text after it. */
+ if (i != bytes_read - 1)
+ XWRITE(STDOUT_FILENO, &buffer[i + 1],
+ bytes_read - (i + 1));
+ return 0;
+ }
+ }
+ /* Not enough newlines in that bufferfull. */
+ if (pos == 0) {
+ /* Not enough lines in the file; print the entire file. */
+ lseek(fd, (off_t) 0, SEEK_SET);
+ return 0;
+ }
+ pos -= BUFSIZ;
+ lseek(fd, pos, SEEK_SET);
+ }
+ while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0);
+ if (bytes_read == -1) {
+ detailed_error(0, errno, "%s", filename);
+ return 1;
+ }
+ return 0;
}
/* Print the last N_LINES lines from the end of the standard input,
Buffer the text as a linked list of LBUFFERs, adding them as needed.
Return 0 if successful, 1 if an error occured. */
-static int
-pipe_lines (const char *filename, int fd, long int n_lines)
+static int pipe_lines(const char *filename, int fd, long int n_lines)
{
- struct linebuffer
- {
- int nbytes, nlines;
- char buffer[BUFSIZ];
- struct linebuffer *next;
- };
- typedef struct linebuffer LBUFFER;
- LBUFFER *first, *last, *tmp;
- int i; /* Index into buffers. */
- int total_lines = 0; /* Total number of newlines in all buffers. */
- int errors = 0;
-
- first = last = (LBUFFER *) xmalloc (sizeof (LBUFFER));
- first->nbytes = first->nlines = 0;
- first->next = NULL;
- tmp = (LBUFFER *) xmalloc (sizeof (LBUFFER));
-
- /* Input is always read into a fresh buffer. */
- while ((tmp->nbytes = fullRead (fd, tmp->buffer, BUFSIZ)) > 0)
- {
- tmp->nlines = 0;
- tmp->next = NULL;
-
- /* Count the number of newlines just read. */
- for (i = 0; i < tmp->nbytes; i++)
- if (tmp->buffer[i] == '\n')
- ++tmp->nlines;
- total_lines += tmp->nlines;
-
- /* If there is enough room in the last buffer read, just append the new
- one to it. This is because when reading from a pipe, `nbytes' can
- often be very small. */
- if (tmp->nbytes + last->nbytes < BUFSIZ)
- {
- memcpy (&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes);
- last->nbytes += tmp->nbytes;
- last->nlines += tmp->nlines;
- }
- else
- {
- /* If there's not enough room, link the new buffer onto the end of
- the list, then either free up the oldest buffer for the next
- read if that would leave enough lines, or else malloc a new one.
- Some compaction mechanism is possible but probably not
- worthwhile. */
- last = last->next = tmp;
- if (total_lines - first->nlines > n_lines)
- {
- tmp = first;
- total_lines -= first->nlines;
- first = first->next;
- }
- else
- tmp = (LBUFFER *) xmalloc (sizeof (LBUFFER));
- }
- }
- if (tmp->nbytes == -1)
- {
- error (0, errno, "%s", filename);
- errors = 1;
- free ((char *) tmp);
- goto free_lbuffers;
- }
-
- free ((char *) tmp);
-
- /* This prevents a core dump when the pipe contains no newlines. */
- if (n_lines == 0)
- goto free_lbuffers;
-
- /* Count the incomplete line on files that don't end with a newline. */
- if (last->buffer[last->nbytes - 1] != '\n')
- {
- ++last->nlines;
- ++total_lines;
- }
-
- /* Run through the list, printing lines. First, skip over unneeded
- buffers. */
- for (tmp = first; total_lines - tmp->nlines > n_lines; tmp = tmp->next)
- total_lines -= tmp->nlines;
-
- /* Find the correct beginning, then print the rest of the file. */
- if (total_lines > n_lines)
- {
- char *cp;
-
- /* Skip `total_lines' - `n_lines' newlines. We made sure that
- `total_lines' - `n_lines' <= `tmp->nlines'. */
- cp = tmp->buffer;
- for (i = total_lines - n_lines; i; --i)
- while (*cp++ != '\n')
- /* Do nothing. */ ;
- i = cp - tmp->buffer;
- }
- else
- i = 0;
- XWRITE (STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i);
-
- for (tmp = tmp->next; tmp; tmp = tmp->next)
- XWRITE (STDOUT_FILENO, tmp->buffer, tmp->nbytes);
-
-free_lbuffers:
- while (first)
- {
- tmp = first->next;
- free ((char *) first);
- first = tmp;
- }
- return errors;
+ struct linebuffer {
+ int nbytes, nlines;
+ char buffer[BUFSIZ];
+ struct linebuffer *next;
+ };
+ typedef struct linebuffer LBUFFER;
+ LBUFFER *first, *last, *tmp;
+ int i; /* Index into buffers. */
+ int total_lines = 0; /* Total number of newlines in all buffers. */
+ int errors = 0;
+
+ first = last = (LBUFFER *) xmalloc(sizeof(LBUFFER));
+ first->nbytes = first->nlines = 0;
+ first->next = NULL;
+ tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER));
+
+ /* Input is always read into a fresh buffer. */
+ while ((tmp->nbytes = fullRead(fd, tmp->buffer, BUFSIZ)) > 0) {
+ tmp->nlines = 0;
+ tmp->next = NULL;
+
+ /* Count the number of newlines just read. */
+ for (i = 0; i < tmp->nbytes; i++)
+ if (tmp->buffer[i] == '\n')
+ ++tmp->nlines;
+ total_lines += tmp->nlines;
+
+ /* If there is enough room in the last buffer read, just append the new
+ one to it. This is because when reading from a pipe, `nbytes' can
+ often be very small. */
+ if (tmp->nbytes + last->nbytes < BUFSIZ) {
+ memcpy(&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes);
+ last->nbytes += tmp->nbytes;
+ last->nlines += tmp->nlines;
+ } else {
+ /* If there's not enough room, link the new buffer onto the end of
+ the list, then either free up the oldest buffer for the next
+ read if that would leave enough lines, or else malloc a new one.
+ Some compaction mechanism is possible but probably not
+ worthwhile. */
+ last = last->next = tmp;
+ if (total_lines - first->nlines > n_lines) {
+ tmp = first;
+ total_lines -= first->nlines;
+ first = first->next;
+ } else
+ tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER));
+ }
+ }
+ if (tmp->nbytes == -1) {
+ detailed_error(0, errno, "%s", filename);
+ errors = 1;
+ free((char *) tmp);
+ goto free_lbuffers;
+ }
+
+ free((char *) tmp);
+
+ /* This prevents a core dump when the pipe contains no newlines. */
+ if (n_lines == 0)
+ goto free_lbuffers;
+
+ /* Count the incomplete line on files that don't end with a newline. */
+ if (last->buffer[last->nbytes - 1] != '\n') {
+ ++last->nlines;
+ ++total_lines;
+ }
+
+ /* Run through the list, printing lines. First, skip over unneeded
+ buffers. */
+ for (tmp = first; total_lines - tmp->nlines > n_lines; tmp = tmp->next)
+ total_lines -= tmp->nlines;
+
+ /* Find the correct beginning, then print the rest of the file. */
+ if (total_lines > n_lines) {
+ char *cp;
+
+ /* Skip `total_lines' - `n_lines' newlines. We made sure that
+ `total_lines' - `n_lines' <= `tmp->nlines'. */
+ cp = tmp->buffer;
+ for (i = total_lines - n_lines; i; --i)
+ while (*cp++ != '\n')
+ /* Do nothing. */ ;
+ i = cp - tmp->buffer;
+ } else
+ i = 0;
+ XWRITE(STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i);
+
+ for (tmp = tmp->next; tmp; tmp = tmp->next)
+ XWRITE(STDOUT_FILENO, tmp->buffer, tmp->nbytes);
+
+ free_lbuffers:
+ while (first) {
+ tmp = first->next;
+ free((char *) first);
+ first = tmp;
+ }
+ return errors;
}
/* Print the last N_BYTES characters from the end of pipe FD.
This is a stripped down version of pipe_lines.
Return 0 if successful, 1 if an error occurred. */
-static int
-pipe_bytes (const char *filename, int fd, off_t n_bytes)
+static int pipe_bytes(const char *filename, int fd, off_t n_bytes)
{
- struct charbuffer
- {
- int nbytes;
- char buffer[BUFSIZ];
- struct charbuffer *next;
- };
- typedef struct charbuffer CBUFFER;
- CBUFFER *first, *last, *tmp;
- int i; /* Index into buffers. */
- int total_bytes = 0; /* Total characters in all buffers. */
- int errors = 0;
-
- first = last = (CBUFFER *) xmalloc (sizeof (CBUFFER));
- first->nbytes = 0;
- first->next = NULL;
- tmp = (CBUFFER *) xmalloc (sizeof (CBUFFER));
-
- /* Input is always read into a fresh buffer. */
- while ((tmp->nbytes = fullRead (fd, tmp->buffer, BUFSIZ)) > 0)
- {
- tmp->next = NULL;
-
- total_bytes += tmp->nbytes;
- /* If there is enough room in the last buffer read, just append the new
- one to it. This is because when reading from a pipe, `nbytes' can
- often be very small. */
- if (tmp->nbytes + last->nbytes < BUFSIZ)
- {
- memcpy (&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes);
- last->nbytes += tmp->nbytes;
- }
- else
- {
- /* If there's not enough room, link the new buffer onto the end of
- the list, then either free up the oldest buffer for the next
- read if that would leave enough characters, or else malloc a new
- one. Some compaction mechanism is possible but probably not
- worthwhile. */
- last = last->next = tmp;
- if (total_bytes - first->nbytes > n_bytes)
- {
- tmp = first;
- total_bytes -= first->nbytes;
- first = first->next;
- }
- else
- {
- tmp = (CBUFFER *) xmalloc (sizeof (CBUFFER));
- }
- }
- }
- if (tmp->nbytes == -1)
- {
- error (0, errno, "%s", filename);
- errors = 1;
- free ((char *) tmp);
- goto free_cbuffers;
- }
-
- free ((char *) tmp);
-
- /* Run through the list, printing characters. First, skip over unneeded
- buffers. */
- for (tmp = first; total_bytes - tmp->nbytes > n_bytes; tmp = tmp->next)
- total_bytes -= tmp->nbytes;
-
- /* Find the correct beginning, then print the rest of the file.
- We made sure that `total_bytes' - `n_bytes' <= `tmp->nbytes'. */
- if (total_bytes > n_bytes)
- i = total_bytes - n_bytes;
- else
- i = 0;
- XWRITE (STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i);
-
- for (tmp = tmp->next; tmp; tmp = tmp->next)
- XWRITE (STDOUT_FILENO, tmp->buffer, tmp->nbytes);
-
-free_cbuffers:
- while (first)
- {
- tmp = first->next;
- free ((char *) first);
- first = tmp;
- }
- return errors;
+ struct charbuffer {
+ int nbytes;
+ char buffer[BUFSIZ];
+ struct charbuffer *next;
+ };
+ typedef struct charbuffer CBUFFER;
+ CBUFFER *first, *last, *tmp;
+ int i; /* Index into buffers. */
+ int total_bytes = 0; /* Total characters in all buffers. */
+ int errors = 0;
+
+ first = last = (CBUFFER *) xmalloc(sizeof(CBUFFER));
+ first->nbytes = 0;
+ first->next = NULL;
+ tmp = (CBUFFER *) xmalloc(sizeof(CBUFFER));
+
+ /* Input is always read into a fresh buffer. */
+ while ((tmp->nbytes = fullRead(fd, tmp->buffer, BUFSIZ)) > 0) {
+ tmp->next = NULL;
+
+ total_bytes += tmp->nbytes;
+ /* If there is enough room in the last buffer read, just append the new
+ one to it. This is because when reading from a pipe, `nbytes' can
+ often be very small. */
+ if (tmp->nbytes + last->nbytes < BUFSIZ) {
+ memcpy(&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes);
+ last->nbytes += tmp->nbytes;
+ } else {
+ /* If there's not enough room, link the new buffer onto the end of
+ the list, then either free up the oldest buffer for the next
+ read if that would leave enough characters, or else malloc a new
+ one. Some compaction mechanism is possible but probably not
+ worthwhile. */
+ last = last->next = tmp;
+ if (total_bytes - first->nbytes > n_bytes) {
+ tmp = first;
+ total_bytes -= first->nbytes;
+ first = first->next;
+ } else {
+ tmp = (CBUFFER *) xmalloc(sizeof(CBUFFER));
+ }
+ }
+ }
+ if (tmp->nbytes == -1) {
+ detailed_error(0, errno, "%s", filename);
+ errors = 1;
+ free((char *) tmp);
+ goto free_cbuffers;
+ }
+
+ free((char *) tmp);
+
+ /* Run through the list, printing characters. First, skip over unneeded
+ buffers. */
+ for (tmp = first; total_bytes - tmp->nbytes > n_bytes; tmp = tmp->next)
+ total_bytes -= tmp->nbytes;
+
+ /* Find the correct beginning, then print the rest of the file.
+ We made sure that `total_bytes' - `n_bytes' <= `tmp->nbytes'. */
+ if (total_bytes > n_bytes)
+ i = total_bytes - n_bytes;
+ else
+ i = 0;
+ XWRITE(STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i);
+
+ for (tmp = tmp->next; tmp; tmp = tmp->next)
+ XWRITE(STDOUT_FILENO, tmp->buffer, tmp->nbytes);
+
+ free_cbuffers:
+ while (first) {
+ tmp = first->next;
+ free((char *) first);
+ first = tmp;
+ }
+ return errors;
}
/* Skip N_BYTES characters from the start of pipe FD, and print
any extra characters that were read beyond that.
Return 1 on error, 0 if ok. */
-static int
-start_bytes (const char *filename, int fd, off_t n_bytes)
+static int start_bytes(const char *filename, int fd, off_t n_bytes)
{
- char buffer[BUFSIZ];
- int bytes_read = 0;
-
- while (n_bytes > 0 && (bytes_read = fullRead (fd, buffer, BUFSIZ)) > 0)
- n_bytes -= bytes_read;
- if (bytes_read == -1)
- {
- error (0, errno, "%s", filename);
- return 1;
- }
- else if (n_bytes < 0)
- XWRITE (STDOUT_FILENO, &buffer[bytes_read + n_bytes], -n_bytes);
- return 0;
+ char buffer[BUFSIZ];
+ int bytes_read = 0;
+
+ while (n_bytes > 0 && (bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0)
+ n_bytes -= bytes_read;
+ if (bytes_read == -1) {
+ detailed_error(0, errno, "%s", filename);
+ return 1;
+ } else if (n_bytes < 0)
+ XWRITE(STDOUT_FILENO, &buffer[bytes_read + n_bytes], -n_bytes);
+ return 0;
}
/* Skip N_LINES lines at the start of file or pipe FD, and print
any extra characters that were read beyond that.
Return 1 on error, 0 if ok. */
-static int
-start_lines (const char *filename, int fd, long int n_lines)
+static int start_lines(const char *filename, int fd, long int n_lines)
{
- char buffer[BUFSIZ];
- int bytes_read = 0;
- int bytes_to_skip = 0;
-
- while (n_lines && (bytes_read = fullRead (fd, buffer, BUFSIZ)) > 0)
- {
- bytes_to_skip = 0;
- while (bytes_to_skip < bytes_read)
- if (buffer[bytes_to_skip++] == '\n' && --n_lines == 0)
- break;
- }
- if (bytes_read == -1)
- {
- error (0, errno, "%s", filename);
- return 1;
- }
- else if (bytes_to_skip < bytes_read)
- {
- XWRITE (STDOUT_FILENO, &buffer[bytes_to_skip],
- bytes_read - bytes_to_skip);
- }
- return 0;
+ char buffer[BUFSIZ];
+ int bytes_read = 0;
+ int bytes_to_skip = 0;
+
+ while (n_lines && (bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0) {
+ bytes_to_skip = 0;
+ while (bytes_to_skip < bytes_read)
+ if (buffer[bytes_to_skip++] == '\n' && --n_lines == 0)
+ break;
+ }
+ if (bytes_read == -1) {
+ detailed_error(0, errno, "%s", filename);
+ return 1;
+ } else if (bytes_to_skip < bytes_read) {
+ XWRITE(STDOUT_FILENO, &buffer[bytes_to_skip],
+ bytes_read - bytes_to_skip);
+ }
+ return 0;
}
/* Display file FILENAME from the current position in FD to the end.
If `forever' is nonzero, keep reading from the end of the file
until killed. Return the number of bytes read from the file. */
-static long
-dump_remainder (const char *filename, int fd)
+static long dump_remainder(const char *filename, int fd)
{
- char buffer[BUFSIZ];
- int bytes_read;
- long total;
-
- total = 0;
-output:
- while ((bytes_read = fullRead (fd, buffer, BUFSIZ)) > 0)
- {
- XWRITE (STDOUT_FILENO, buffer, bytes_read);
- total += bytes_read;
- }
- if (bytes_read == -1)
- error (EXIT_FAILURE, errno, "%s", filename);
- if (forever)
- {
- fflush (stdout);
- sleep (1);
- goto output;
- }
- else
- {
- if (forever_multiple)
- fflush (stdout);
- }
-
- return total;
+ char buffer[BUFSIZ];
+ int bytes_read;
+ long total;
+
+ total = 0;
+ output:
+ while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0) {
+ XWRITE(STDOUT_FILENO, buffer, bytes_read);
+ total += bytes_read;
+ }
+ if (bytes_read == -1)
+ detailed_error(EXIT_FAILURE, errno, "%s", filename);
+ if (forever) {
+ fflush(stdout);
+ sleep(1);
+ goto output;
+ } else {
+ if (forever_multiple)
+ fflush(stdout);
+ }
+
+ return total;
}
/* Tail NFILES (>1) files forever until killed. The file names are in
none of them have changed size in one iteration, we sleep for a
second and try again. We do this until the user interrupts us. */
-static void
-tail_forever (char **names, int nfiles)
+static void tail_forever(char **names, int nfiles)
{
- int last;
-
- last = -1;
-
- while (1)
- {
- int i;
- int changed;
-
- changed = 0;
- for (i = 0; i < nfiles; i++)
- {
- struct stat stats;
-
- if (file_descs[i] < 0)
- continue;
- if (fstat (file_descs[i], &stats) < 0)
- {
- error (0, errno, "%s", names[i]);
- file_descs[i] = -1;
- continue;
- }
- if (stats.st_size == file_sizes[i])
- continue;
-
- /* This file has changed size. Print out what we can, and
- then keep looping. */
-
- changed = 1;
-
- if (stats.st_size < file_sizes[i])
- {
- write_header (names[i], "file truncated");
- last = i;
- lseek (file_descs[i], stats.st_size, SEEK_SET);
- file_sizes[i] = stats.st_size;
- continue;
- }
-
- if (i != last)
- {
- if (print_headers)
- write_header (names[i], NULL);
- last = i;
- }
- file_sizes[i] += dump_remainder (names[i], file_descs[i]);
- }
-
- /* If none of the files changed size, sleep. */
- if (! changed)
- sleep (1);
- }
+ int last;
+
+ last = -1;
+
+ while (1) {
+ int i;
+ int changed;
+
+ changed = 0;
+ for (i = 0; i < nfiles; i++) {
+ struct stat stats;
+
+ if (file_descs[i] < 0)
+ continue;
+ if (fstat(file_descs[i], &stats) < 0) {
+ detailed_error(0, errno, "%s", names[i]);
+ file_descs[i] = -1;
+ continue;
+ }
+ if (stats.st_size == file_sizes[i])
+ continue;
+
+ /* This file has changed size. Print out what we can, and
+ then keep looping. */
+
+ changed = 1;
+
+ if (stats.st_size < file_sizes[i]) {
+ write_header(names[i], "file truncated");
+ last = i;
+ lseek(file_descs[i], stats.st_size, SEEK_SET);
+ file_sizes[i] = stats.st_size;
+ continue;
+ }
+
+ if (i != last) {
+ if (print_headers)
+ write_header(names[i], NULL);
+ last = i;
+ }
+ file_sizes[i] += dump_remainder(names[i], file_descs[i]);
+ }
+
+ /* If none of the files changed size, sleep. */
+ if (!changed)
+ sleep(1);
+ }
}
/* Output the last N_BYTES bytes of file FILENAME open for reading in FD.
Return 0 if successful, 1 if an error occurred. */
-static int
-tail_bytes (const char *filename, int fd, off_t n_bytes)
+static int tail_bytes(const char *filename, int fd, off_t n_bytes)
{
- struct stat stats;
-
- /* FIXME: resolve this like in dd.c. */
- /* Use fstat instead of checking for errno == ESPIPE because
- lseek doesn't work on some special files but doesn't return an
- error, either. */
- if (fstat (fd, &stats))
- {
- error (0, errno, "%s", filename);
- return 1;
- }
-
- if (from_start)
- {
- if (S_ISREG (stats.st_mode))
- lseek (fd, n_bytes, SEEK_CUR);
- else if (start_bytes (filename, fd, n_bytes))
- return 1;
- dump_remainder (filename, fd);
- }
- else
- {
- if (S_ISREG (stats.st_mode))
- {
- off_t current_pos, end_pos;
- size_t bytes_remaining;
-
- if ((current_pos = lseek (fd, (off_t) 0, SEEK_CUR)) != -1
- && (end_pos = lseek (fd, (off_t) 0, SEEK_END)) != -1)
- {
- off_t diff;
- /* Be careful here. The current position may actually be
- beyond the end of the file. */
- bytes_remaining = (diff = end_pos - current_pos) < 0 ? 0 : diff;
- }
- else
- {
- error (0, errno, "%s", filename);
- return 1;
- }
-
- if (bytes_remaining <= n_bytes)
- {
- /* From the current position to end of file, there are no
- more bytes than have been requested. So reposition the
- file pointer to the incoming current position and print
- everything after that. */
- lseek (fd, current_pos, SEEK_SET);
- }
- else
- {
- /* There are more bytes remaining than were requested.
- Back up. */
- lseek (fd, -n_bytes, SEEK_END);
- }
- dump_remainder (filename, fd);
- }
- else
- return pipe_bytes (filename, fd, n_bytes);
- }
- return 0;
+ struct stat stats;
+
+ /* FIXME: resolve this like in dd.c. */
+ /* Use fstat instead of checking for errno == ESPIPE because
+ lseek doesn't work on some special files but doesn't return an
+ error, either. */
+ if (fstat(fd, &stats)) {
+ detailed_error(0, errno, "%s", filename);
+ return 1;
+ }
+
+ if (from_start) {
+ if (S_ISREG(stats.st_mode))
+ lseek(fd, n_bytes, SEEK_CUR);
+ else if (start_bytes(filename, fd, n_bytes))
+ return 1;
+ dump_remainder(filename, fd);
+ } else {
+ if (S_ISREG(stats.st_mode)) {
+ off_t current_pos, end_pos;
+ size_t bytes_remaining;
+
+ if ((current_pos = lseek(fd, (off_t) 0, SEEK_CUR)) != -1
+ && (end_pos = lseek(fd, (off_t) 0, SEEK_END)) != -1) {
+ off_t diff;
+
+ /* Be careful here. The current position may actually be
+ beyond the end of the file. */
+ bytes_remaining = (diff =
+ end_pos - current_pos) < 0 ? 0 : diff;
+ } else {
+ detailed_error(0, errno, "%s", filename);
+ return 1;
+ }
+
+ if (bytes_remaining <= n_bytes) {
+ /* From the current position to end of file, there are no
+ more bytes than have been requested. So reposition the
+ file pointer to the incoming current position and print
+ everything after that. */
+ lseek(fd, current_pos, SEEK_SET);
+ } else {
+ /* There are more bytes remaining than were requested.
+ Back up. */
+ lseek(fd, -n_bytes, SEEK_END);
+ }
+ dump_remainder(filename, fd);
+ } else
+ return pipe_bytes(filename, fd, n_bytes);
+ }
+ return 0;
}
/* Output the last N_LINES lines of file FILENAME open for reading in FD.
Return 0 if successful, 1 if an error occurred. */
-static int
-tail_lines (const char *filename, int fd, long int n_lines)
+static int tail_lines(const char *filename, int fd, long int n_lines)
{
- struct stat stats;
- off_t length;
-
- if (fstat (fd, &stats))
- {
- error (0, errno, "%s", filename);
- return 1;
- }
-
- if (from_start)
- {
- if (start_lines (filename, fd, n_lines))
- return 1;
- dump_remainder (filename, fd);
- }
- else
- {
- /* Use file_lines only if FD refers to a regular file with
- its file pointer positioned at beginning of file. */
- /* FIXME: adding the lseek conjunct is a kludge.
- Once there's a reasonable test suite, fix the true culprit:
- file_lines. file_lines shouldn't presume that the input
- file pointer is initially positioned to beginning of file. */
- if (S_ISREG (stats.st_mode)
- && lseek (fd, (off_t) 0, SEEK_CUR) == (off_t) 0)
- {
- length = lseek (fd, (off_t) 0, SEEK_END);
- if (length != 0 && file_lines (filename, fd, n_lines, length))
- return 1;
- dump_remainder (filename, fd);
- }
- else
- return pipe_lines (filename, fd, n_lines);
- }
- return 0;
+ struct stat stats;
+ off_t length;
+
+ if (fstat(fd, &stats)) {
+ detailed_error(0, errno, "%s", filename);
+ return 1;
+ }
+
+ if (from_start) {
+ if (start_lines(filename, fd, n_lines))
+ return 1;
+ dump_remainder(filename, fd);
+ } else {
+ /* Use file_lines only if FD refers to a regular file with
+ its file pointer positioned at beginning of file. */
+ /* FIXME: adding the lseek conjunct is a kludge.
+ Once there's a reasonable test suite, fix the true culprit:
+ file_lines. file_lines shouldn't presume that the input
+ file pointer is initially positioned to beginning of file. */
+ if (S_ISREG(stats.st_mode)
+ && lseek(fd, (off_t) 0, SEEK_CUR) == (off_t) 0) {
+ length = lseek(fd, (off_t) 0, SEEK_END);
+ if (length != 0 && file_lines(filename, fd, n_lines, length))
+ return 1;
+ dump_remainder(filename, fd);
+ } else
+ return pipe_lines(filename, fd, n_lines);
+ }
+ return 0;
}
/* Display the last N_UNITS units of file FILENAME, open for reading
in FD.
Return 0 if successful, 1 if an error occurred. */
-static int
-tail (const char *filename, int fd, off_t n_units)
+static int tail(const char *filename, int fd, off_t n_units)
{
- if (count_lines)
- return tail_lines (filename, fd, (long) n_units);
- else
- return tail_bytes (filename, fd, n_units);
+ if (count_lines)
+ return tail_lines(filename, fd, (long) n_units);
+ else
+ return tail_bytes(filename, fd, n_units);
}
/* Display the last N_UNITS units of file FILENAME.
FILENUM is this file's index in the list of files the user gave.
Return 0 if successful, 1 if an error occurred. */
-static int
-tail_file (const char *filename, off_t n_units, int filenum)
+static int tail_file(const char *filename, off_t n_units, int filenum)
{
- int fd, errors;
- struct stat stats;
-
- if (!strcmp (filename, "-"))
- {
- have_read_stdin = 1;
- filename = "standard input";
- if (print_headers)
- write_header (filename, NULL);
- errors = tail (filename, 0, n_units);
- if (forever_multiple)
- {
- if (fstat (0, &stats) < 0)
- {
- error (0, errno, "standard input");
- errors = 1;
- }
- else if (!S_ISREG (stats.st_mode))
- {
- error (0, 0,
- "standard input: cannot follow end of non-regular file");
- errors = 1;
- }
- if (errors)
- file_descs[filenum] = -1;
- else
- {
- file_descs[filenum] = 0;
- file_sizes[filenum] = stats.st_size;
- }
- }
- }
- else
- {
- /* Not standard input. */
- fd = open (filename, O_RDONLY);
- if (fd == -1)
- {
- if (forever_multiple)
- file_descs[filenum] = -1;
- error (0, errno, "%s", filename);
- errors = 1;
- }
- else
- {
- if (print_headers)
- write_header (filename, NULL);
- errors = tail (filename, fd, n_units);
- if (forever_multiple)
- {
- if (fstat (fd, &stats) < 0)
- {
- error (0, errno, "%s", filename);
- errors = 1;
- }
- else if (!S_ISREG (stats.st_mode))
- {
- error (0, 0, "%s: cannot follow end of non-regular file",
- filename);
- errors = 1;
- }
- if (errors)
- {
- close (fd);
- file_descs[filenum] = -1;
+ int fd, errors;
+ struct stat stats;
+
+ if (!strcmp(filename, "-")) {
+ have_read_stdin = 1;
+ filename = "standard input";
+ if (print_headers)
+ write_header(filename, NULL);
+ errors = tail(filename, 0, n_units);
+ if (forever_multiple) {
+ if (fstat(0, &stats) < 0) {
+ detailed_error(0, errno, "standard input");
+ errors = 1;
+ } else if (!S_ISREG(stats.st_mode)) {
+ detailed_error(0, 0,
+ "standard input: cannot follow end of non-regular file");
+ errors = 1;
+ }
+ if (errors)
+ file_descs[filenum] = -1;
+ else {
+ file_descs[filenum] = 0;
+ file_sizes[filenum] = stats.st_size;
+ }
}
- else
- {
- file_descs[filenum] = fd;
- file_sizes[filenum] = stats.st_size;
+ } else {
+ /* Not standard input. */
+ fd = open(filename, O_RDONLY);
+ if (fd == -1) {
+ if (forever_multiple)
+ file_descs[filenum] = -1;
+ detailed_error(0, errno, "%s", filename);
+ errors = 1;
+ } else {
+ if (print_headers)
+ write_header(filename, NULL);
+ errors = tail(filename, fd, n_units);
+ if (forever_multiple) {
+ if (fstat(fd, &stats) < 0) {
+ detailed_error(0, errno, "%s", filename);
+ errors = 1;
+ } else if (!S_ISREG(stats.st_mode)) {
+ detailed_error(0, 0,
+ "%s: cannot follow end of non-regular file",
+ filename);
+ errors = 1;
+ }
+ if (errors) {
+ close(fd);
+ file_descs[filenum] = -1;
+ } else {
+ file_descs[filenum] = fd;
+ file_sizes[filenum] = stats.st_size;
+ }
+ } else {
+ if (close(fd)) {
+ detailed_error(0, errno, "%s", filename);
+ errors = 1;
+ }
+ }
}
- }
- else
- {
- if (close (fd))
- {
- error (0, errno, "%s", filename);
- errors = 1;
- }
- }
}
- }
- return errors;
+ return errors;
}
-extern int
-tail_main (int argc, char **argv)
+extern int tail_main(int argc, char **argv)
{
- int stopit = 0;
- enum header_mode header_mode = multiple_files;
- int exit_status = 0;
- /* If from_start, the number of items to skip before printing; otherwise,
- the number of items at the end of the file to print. Initially, -1
- means the value has not been set. */
- off_t n_units = -1;
- int n_files;
- char **file;
-
- program_name = argv[0];
- have_read_stdin = 0;
- count_lines = 1;
- forever = forever_multiple = from_start = print_headers = 0;
-
- /* Parse any options */
- //fprintf(stderr, "argc=%d, argv=%s\n", argc, *argv);
- while (--argc > 0 && ( **(++argv) == '-' || **argv == '+' )) {
- if (**argv == '+') {
- from_start = 1;
- }
- stopit = 0;
- while (stopit == 0 && *(++(*argv))) {
- switch (**argv) {
- case 'c':
- count_lines = 0;
-
- if (--argc < 1) {
- usage(tail_usage);
- }
- n_units = getNum(*(++argv));
- stopit = 1;
- break;
-
- case 'f':
- forever = 1;
- break;
-
- case 'n':
- count_lines = 1;
-
- if (--argc < 1) {
- usage(tail_usage);
- }
- n_units = atol(*(++argv));
- stopit = 1;
- break;
-
- case 'q':
- header_mode = never;
- break;
-
- case 'v':
- header_mode = always;
- break;
-
- default:
- usage (tail_usage);
- }
- }
- }
-
-
- if (n_units == -1)
- n_units = DEFAULT_N_LINES;
-
- /* To start printing with item N_UNITS from the start of the file, skip
- N_UNITS - 1 items. `tail +0' is actually meaningless, but for Unix
- compatibility it's treated the same as `tail +1'. */
- if (from_start)
- {
- if (n_units)
- --n_units;
- }
-
- n_files = argc;
- file = argv;
-
- if (n_files > 1 && forever)
- {
- forever_multiple = 1;
- forever = 0;
- file_descs = (int *) xmalloc (n_files * sizeof (int));
- file_sizes = (off_t *) xmalloc (n_files * sizeof (off_t));
- }
-
- if (header_mode == always
- || (header_mode == multiple_files && n_files > 1))
- print_headers = 1;
-
- if (n_files == 0)
- {
- exit_status |= tail_file ("-", n_units, 0);
- }
- else
- {
- int i;
- for (i = 0; i < n_files; i++)
- exit_status |= tail_file (file[i], n_units, i);
-
- if (forever_multiple)
- tail_forever (file, n_files);
- }
-
- if (have_read_stdin && close (0) < 0)
- error (EXIT_FAILURE, errno, "-");
- if (fclose (stdout) == EOF)
- error (EXIT_FAILURE, errno, "write error");
- exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+ int stopit = 0;
+ enum header_mode header_mode = multiple_files;
+ int exit_status = 0;
+
+ /* If from_start, the number of items to skip before printing; otherwise,
+ the number of items at the end of the file to print. Initially, -1
+ means the value has not been set. */
+ off_t n_units = -1;
+ int n_files;
+ char **file;
+
+ program_name = argv[0];
+ have_read_stdin = 0;
+ count_lines = 1;
+ forever = forever_multiple = from_start = print_headers = 0;
+
+ /* Parse any options */
+ //fprintf(stderr, "argc=%d, argv=%s\n", argc, *argv);
+ while (--argc > 0 && (**(++argv) == '-' || **argv == '+')) {
+ if (**argv == '+') {
+ from_start = 1;
+ }
+ stopit = 0;
+ while (stopit == 0 && *(++(*argv))) {
+ switch (**argv) {
+ case 'c':
+ count_lines = 0;
+
+ if (--argc < 1) {
+ usage(tail_usage);
+ }
+ n_units = getNum(*(++argv));
+ stopit = 1;
+ break;
+
+ case 'f':
+ forever = 1;
+ break;
+
+ case 'n':
+ count_lines = 1;
+
+ if (--argc < 1) {
+ usage(tail_usage);
+ }
+ n_units = atol(*(++argv));
+ stopit = 1;
+ break;
+
+ case 'q':
+ header_mode = never;
+ break;
+
+ case 'v':
+ header_mode = always;
+ break;
+
+ default:
+ usage(tail_usage);
+ }
+ }
+ }
+
+
+ if (n_units == -1)
+ n_units = DEFAULT_N_LINES;
+
+ /* To start printing with item N_UNITS from the start of the file, skip
+ N_UNITS - 1 items. `tail +0' is actually meaningless, but for Unix
+ compatibility it's treated the same as `tail +1'. */
+ if (from_start) {
+ if (n_units)
+ --n_units;
+ }
+
+ n_files = argc;
+ file = argv;
+
+ if (n_files > 1 && forever) {
+ forever_multiple = 1;
+ forever = 0;
+ file_descs = (int *) xmalloc(n_files * sizeof(int));
+
+ file_sizes = (off_t *) xmalloc(n_files * sizeof(off_t));
+ }
+
+ if (header_mode == always
+ || (header_mode == multiple_files && n_files > 1))
+ print_headers = 1;
+
+ if (n_files == 0) {
+ exit_status |= tail_file("-", n_units, 0);
+ } else {
+ int i;
+
+ for (i = 0; i < n_files; i++)
+ exit_status |= tail_file(file[i], n_units, i);
+
+ if (forever_multiple)
+ tail_forever(file, n_files);
+ }
+
+ if (have_read_stdin && close(0) < 0)
+ detailed_error(EXIT_FAILURE, errno, "-");
+ if (fclose(stdout) == EOF)
+ detailed_error(EXIT_FAILURE, errno, "write error");
+ exit(exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
}
+
+
+#endif
projects / oweals / busybox.git / blobdiff