/* vi: set sw=4 ts=4: */
-/* 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>.
+/*
+ * Mini tail implementation for busybox
+ *
+ * Copyright (C) 2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
- Compleate Rewrite to correctly support "-NUM", "+NUM", and "-s" by
- E.Allen Soard (esp@espsw.net).
+/* BB_AUDIT SUSv3 compliant (need fancy for -c) */
+/* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/tail.html */
+/* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
+ *
+ * Pretty much rewritten to fix numerous bugs and reduce realloc() calls.
+ * Bugs fixed (although I may have forgotten one or two... it was pretty bad)
+ * 1) mixing printf/write without fflush()ing stdout
+ * 2) no check that any open files are present
+ * 3) optstring had -q taking an arg
+ * 4) no error checking on write in some cases, and a warning even then
+ * 5) q and s interaction bug
+ * 6) no check for lseek error
+ * 7) lseek attempted when count==0 even if arg was +0 (from top)
*/
-#include <sys/types.h>
-#include <fcntl.h>
+
#include <stdio.h>
#include <stdlib.h>
-#include <unistd.h>
#include <string.h>
-#include <getopt.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
#include "busybox.h"
-#define STDIN "standard input"
-#define LINES 0
-#define BYTES 1
-
-static int n_files = 0;
-static char **files = NULL;
-static char * buffer;
-static ssize_t bytes_read=0;
-static ssize_t bs;
-static ssize_t filelocation=0;
-static char pip;
-
-#ifdef BB_FEATURE_SIMPLE_TAIL
-static const char unit_type=LINES;
-#else
-static char unit_type=LINES;
-static char verbose = 0;
-#endif
+static const struct suffix_mult tail_suffixes[] = {
+ { "b", 512 },
+ { "k", 1024 },
+ { "m", 1048576 },
+ { NULL, 0 }
+};
-static off_t units=0;
+static int status;
-static int tail_stream(int fd)
+static void tail_xprint_header(const char *fmt, const char *filename)
{
- ssize_t startpoint;
- ssize_t endpoint=0;
- ssize_t count=0;
- ssize_t filesize=0;
- int direction=1;
-
- filelocation=0;
- startpoint=bs=BUFSIZ;
-
- filesize=lseek(fd, -1, SEEK_END)+1;
- pip=(filesize<=0);
-
- if(units>=0)
- lseek(fd,0,SEEK_SET);
- else {
- direction=-1;
- count=1;
- }
- while(units != 0) {
- if (pip) {
- char * line;
- ssize_t f_size=0;
-
- bs=BUFSIZ;
- line=xmalloc(bs);
- while(1) {
- bytes_read=read(fd,line,bs);
- if(bytes_read<=0)
- break;
- buffer=xrealloc(buffer,f_size+bytes_read);
- memcpy(&buffer[f_size],line,bytes_read);
- filelocation=f_size+=bytes_read;
- }
- bs=f_size;
- if(direction<0)
- bs--;
- if (line)
- free(line);
- } else {
- filelocation = lseek(fd, 0, SEEK_CUR);
- if(direction<0) {
- if(filelocation<bs)
- bs=filelocation;
- filelocation = lseek(fd, -bs, SEEK_CUR);
- }
- bytes_read = read(fd, buffer, bs);
- if (bytes_read <= 0)
- break;
- bs=bytes_read;
- }
- startpoint=bs;
- if(direction>0) {
- endpoint=startpoint;
- startpoint=0;
- }
- for(;startpoint!=endpoint;startpoint+=direction) {
-#ifndef BB_FEATURE_SIMPLE_TAIL
- if(unit_type==BYTES)
- count++;
- else
-#endif
- if(buffer[startpoint-1]=='\n')
- count++;
- if (!pip)
- filelocation=lseek(fd,0,SEEK_CUR);
- if(count==units*direction)
- break;
- }
- if((count==units*direction) | pip)
- break;
- if(direction<0){
- filelocation = lseek(fd, -bytes_read, SEEK_CUR);
- if(filelocation==0)
- break;
- }
+ /* If we get an output error, there is really no sense in continuing. */
+ if (dprintf(STDOUT_FILENO, fmt, filename) < 0) {
+ bb_perror_nomsg_and_die();
}
- if(pip && (direction<0))
- bs++;
- bytes_read=bs-startpoint;
- memcpy(&buffer[0],&buffer[startpoint],bytes_read);
+}
- return 0;
+/* len should probably be size_t */
+static void tail_xbb_full_write(const char *buf, size_t len)
+{
+ /* If we get a write error, there is really no sense in continuing. */
+ if (bb_full_write(STDOUT_FILENO, buf, len) < 0) {
+ bb_perror_nomsg_and_die();
+ }
}
-void add_file(char *name)
+static ssize_t tail_read(int fd, char *buf, size_t count)
{
- ++n_files;
- files = xrealloc(files, n_files);
- files[n_files - 1] = (char *) xmalloc(strlen(name) + 1);
- strcpy(files[n_files - 1], name);
+ ssize_t r;
+ off_t current,end;
+ struct stat sbuf;
+
+ end = current = lseek(fd, 0, SEEK_CUR);
+ if (!fstat(fd, &sbuf))
+ end = sbuf.st_size;
+ lseek(fd, end < current ? 0 : current, SEEK_SET);
+ if ((r = safe_read(fd, buf, count)) < 0) {
+ bb_perror_msg("read");
+ status = EXIT_FAILURE;
+ }
+
+ return r;
}
+static const char tail_opts[] =
+ "fn:c:"
+#if ENABLE_FEATURE_FANCY_TAIL
+ "qs:v"
+#endif
+ ;
+
+static const char header_fmt[] = "\n==> %s <==\n";
+
int tail_main(int argc, char **argv)
{
- int show_headers = 1;
- int test;
- int opt;
- char follow=0;
- int sleep_int=1;
- int *fd;
+ long count = 10;
+ unsigned int sleep_period = 1;
+ int from_top = 0;
+ int follow = 0;
+ int header_threshhold = 1;
+ int count_bytes = 0;
+
+ char *tailbuf;
+ size_t tailbufsize;
+ int taillen = 0;
+ int newline = 0;
+
+ int *fds, nfiles, nread, nwrite, seen, i, opt;
+ char *s, *buf;
+ const char *fmt;
- opterr = 0;
-
- while ((opt=getopt(argc,argv,"c:fhn:s:q:v")) >0) {
+#if !ENABLE_DEBUG_YANK_SUSv2 || ENABLE_FEATURE_FANCY_TAIL
+ /* Allow legacy syntax of an initial numeric option without -n. */
+ if (argc >=2 && ((argv[1][0] == '+') || ((argv[1][0] == '-')
+ /* && (isdigit)(argv[1][1]) */
+ && (((unsigned int)(argv[1][1] - '0')) <= 9))))
+ {
+ optind = 2;
+ optarg = argv[1];
+ goto GET_COUNT;
+ }
+#endif
+ while ((opt = getopt(argc, argv, tail_opts)) > 0) {
switch (opt) {
-#ifndef BB_FEATURE_SIMPLE_TAIL
- case 'c':
- unit_type = BYTES;
- test = atoi(optarg);
- if(test==0)
- usage(tail_usage);
- if(optarg[strlen(optarg)-1]>'9') {
- switch (optarg[strlen(optarg)-1]) {
- case 'b':
- test *= 512;
- break;
- case 'k':
- test *= 1024;
- break;
- case 'm':
- test *= (1024 * 1024);
- break;
- default:
- fprintf(stderr,"Size must be b,k, or m.");
- usage(tail_usage);
+ case 'f':
+ follow = 1;
+ break;
+ case 'c':
+ count_bytes = 1;
+ /* FALLS THROUGH */
+ case 'n':
+#if !ENABLE_DEBUG_YANK_SUSv2 || ENABLE_FEATURE_FANCY_TAIL
+ GET_COUNT:
+#endif
+ count = bb_xgetlarg10_sfx(optarg, tail_suffixes);
+ /* Note: Leading whitespace is an error trapped above. */
+ if (*optarg == '+') {
+ from_top = 1;
+ } else {
+ from_top = 0;
}
- }
- if(optarg[0]=='+')
- units=test+1;
- else
- units=-(test+1);
- break;
- case 'q':
- show_headers = 0;
- break;
- case 's':
- sleep_int = atoi(optarg);
- if(sleep_int<1)
- sleep_int=1;
- break;
- case 'v':
- verbose = 1;
- break;
+ if (count < 0) {
+ count = -count;
+ }
+ break;
+#if ENABLE_FEATURE_FANCY_TAIL
+ case 'q':
+ header_threshhold = INT_MAX;
+ break;
+ case 's':
+ sleep_period =bb_xgetularg10_bnd(optarg, 0, UINT_MAX);
+ break;
+ case 'v':
+ header_threshhold = 0;
+ break;
#endif
- case 'f':
- follow = 1;
- break;
- case 'h':
- usage(tail_usage);
- break;
- case 'n':
- test = atoi(optarg);
- if (test) {
- if (optarg[0] == '+')
- units = test;
- else
- units = -(test+1);
- } else
- usage(tail_usage);
- break;
- default:
- errorMsg("\nUnknown arg: %c.\n\n",optopt);
- usage(tail_usage);
+ default:
+ bb_show_usage();
}
}
- while (optind <= argc) {
- if(optind==argc) {
- if (n_files==0)
- add_file(STDIN);
- else
- break;
- }else {
- if (!strcmp(argv[optind], "-")) {
- add_file(STDIN);
- } else {
- add_file(argv[optind]);
- }
- optind++;
+
+ /* open all the files */
+ fds = (int *)xmalloc(sizeof(int) * (argc - optind + 1));
+
+ argv += optind;
+ nfiles = i = 0;
+
+ if ((argc -= optind) == 0) {
+ struct stat statbuf;
+
+ if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) {
+ follow = 0;
}
+ /* --argv; */
+ *argv = (char *) bb_msg_standard_input;
+ goto DO_STDIN;
}
- if(units==0)
- units=-11;
- if(units>0)
- units--;
- fd=xmalloc(sizeof(int)*n_files);
- if (n_files == 1)
-#ifndef BB_FEATURE_SIMPLE_TAIL
- if (!verbose)
-#endif
- show_headers = 0;
- buffer=xmalloc(BUFSIZ);
- for (test = 0; test < n_files; test++) {
- if (show_headers)
- printf("==> %s <==\n", files[test]);
- if (!strcmp(files[test], STDIN))
- fd[test] = 0;
- else
- fd[test] = open(files[test], O_RDONLY);
- if (fd[test] == -1)
- fatalError("Unable to open file %s.\n", files[test]);
- tail_stream(fd[test]);
-
- bs=BUFSIZ;
- while (1) {
- if((filelocation>0 || pip)){
- write(1,buffer,bytes_read);
- }
- bytes_read = read(fd[test], buffer, bs);
- filelocation+=bytes_read;
- if (bytes_read <= 0) {
- break;
- }
- usleep(sleep_int * 1000);
+
+ do {
+ if ((argv[i][0] == '-') && !argv[i][1]) {
+ DO_STDIN:
+ fds[nfiles] = STDIN_FILENO;
+ } else if ((fds[nfiles] = open(argv[i], O_RDONLY)) < 0) {
+ bb_perror_msg("%s", argv[i]);
+ status = EXIT_FAILURE;
+ continue;
}
- if(n_files>1)
- printf("\n");
+ argv[nfiles] = argv[i];
+ ++nfiles;
+ } while (++i < argc);
+
+ if (!nfiles) {
+ bb_error_msg_and_die("no files");
}
- while(1){
- for (test = 0; test < n_files; test++) {
- if(!follow){
- close(fd[test]);
- continue;
- } else {
- sleep(sleep_int);
- bytes_read = read(fd[test], buffer, bs);
- if(bytes_read>0) {
- if (show_headers)
- printf("==> %s <==\n", files[test]);
- write(1,buffer,bytes_read);
- if(n_files>1)
- printf("\n");
+
+ tailbufsize = BUFSIZ;
+
+ /* tail the files */
+ if (from_top < count_bytes) { /* Each is 0 or 1, so true iff 0 < 1. */
+ /* Hence, !from_top && count_bytes */
+ if (tailbufsize < count) {
+ tailbufsize = count + BUFSIZ;
+ }
+ }
+
+ buf = tailbuf = xmalloc(tailbufsize);
+
+ fmt = header_fmt + 1; /* Skip header leading newline on first output. */
+ i = 0;
+ do {
+ /* Be careful. It would be possible to optimize the count-bytes
+ * case if the file is seekable. If you do though, remember that
+ * starting file position may not be the beginning of the file.
+ * Beware of backing up too far. See example in wc.c.
+ */
+ if ((!(count|from_top)) && (lseek(fds[i], 0, SEEK_END) >= 0)) {
+ continue;
+ }
+
+ if (nfiles > header_threshhold) {
+ tail_xprint_header(fmt, argv[i]);
+ fmt = header_fmt;
+ }
+
+ buf = tailbuf;
+ taillen = 0;
+ seen = 1;
+ newline = 0;
+
+ while ((nread = tail_read(fds[i], buf, tailbufsize-taillen)) > 0) {
+ if (from_top) {
+ nwrite = nread;
+ if (seen < count) {
+ if (count_bytes) {
+ nwrite -= (count - seen);
+ seen = count;
+ } else {
+ s = buf;
+ do {
+ --nwrite;
+ if ((*s++ == '\n') && (++seen == count)) {
+ break;
+ }
+ } while (nwrite);
+ }
}
+ tail_xbb_full_write(buf + nread - nwrite, nwrite);
+ } else if (count) {
+ if (count_bytes) {
+ taillen += nread;
+ if (taillen > count) {
+ memmove(tailbuf, tailbuf + taillen - count, count);
+ taillen = count;
+ }
+ } else {
+ int k = nread;
+ int nbuf = 0;
+
+ while (k) {
+ --k;
+ if (buf[k] == '\n') {
+ ++nbuf;
+ }
+ }
+
+ if (newline + nbuf < count) {
+ newline += nbuf;
+ taillen += nread;
+
+ } else {
+ int extra = 0;
+ if (buf[nread-1] != '\n') {
+ extra = 1;
+ }
+
+ k = newline + nbuf + extra - count;
+ s = tailbuf;
+ while (k) {
+ if (*s == '\n') {
+ --k;
+ }
+ ++s;
+ }
+
+ taillen += nread - (s - tailbuf);
+ memmove(tailbuf, s, taillen);
+ newline = count - extra;
+ }
+ if (tailbufsize < taillen + BUFSIZ) {
+ tailbufsize = taillen + BUFSIZ;
+ tailbuf = xrealloc(tailbuf, tailbufsize);
+ }
+ }
+ buf = tailbuf + taillen;
}
}
- if(!follow)
- break;
+
+ if (!from_top) {
+ tail_xbb_full_write(tailbuf, taillen);
+ }
+
+ taillen = 0;
+ } while (++i < nfiles);
+
+ buf = xrealloc(tailbuf, BUFSIZ);
+
+ fmt = NULL;
+
+ while (follow) {
+ sleep(sleep_period);
+ i = 0;
+ do {
+ if (nfiles > header_threshhold) {
+ fmt = header_fmt;
+ }
+ while ((nread = tail_read(fds[i], buf, sizeof(buf))) > 0) {
+ if (fmt) {
+ tail_xprint_header(fmt, argv[i]);
+ fmt = NULL;
+ }
+ tail_xbb_full_write(buf, nread);
+ }
+ } while (++i < nfiles);
}
- if (fd)
- free(fd);
- if (buffer)
- free(buffer);
- if(files)
- free(files);
- return 0;
-}
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+ return status;
+}
projects / oweals / busybox.git / blobdiff