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authorMatt Kraai <kraai@debian.org>2001-01-05 02:57:53 +0000
committerMatt Kraai <kraai@debian.org>2001-01-05 02:57:53 +0000
commit55bccf315edda48fa9f3af4516b0897f29a78a9e (patch)
tree0be02e54fb51eec3d8316105a581e1bf9939ba26 /coreutils/tail.c
parentdefcd5e75eec72aa31e9bdbd9ac854832318f82f (diff)
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Rewrote tail.
Diffstat (limited to 'coreutils/tail.c')
-rw-r--r--coreutils/tail.c456
1 files changed, 203 insertions, 253 deletions
diff --git a/coreutils/tail.c b/coreutils/tail.c
index 5f0381882..8e6488931 100644
--- a/coreutils/tail.c
+++ b/coreutils/tail.c
@@ -1,65 +1,30 @@
1/* vi: set sw=4 ts=4: */ 1/* vi: set sw=4 ts=4: */
2/* tail -- output the last part of file(s) 2/*
3 Copyright (C) 89, 90, 91, 95, 1996 Free Software Foundation, Inc. 3 * Mini tail implementation for busybox
4 4 *
5 This program is free software; you can redistribute it and/or modify 5 *
6 it under the terms of the GNU General Public License as published by 6 * Copyright (C) 2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
7 the Free Software Foundation; either version 2, or (at your option) 7 *
8 any later version. 8 * This program is free software; you can redistribute it and/or modify
9 9 * it under the terms of the GNU General Public License as published by
10 This program is distributed in the hope that it will be useful, 10 * the Free Software Foundation; either version 2 of the License, or
11 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * (at your option) any later version.
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 *
13 GNU General Public License for more details. 13 * This program is distributed in the hope that it will be useful,
14 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 You should have received a copy of the GNU General Public License 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 along with this program; if not, write to the Free Software 16 * General Public License for more details.
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 *
18 18 * You should have received a copy of the GNU General Public License
19 Original version by Paul Rubin <phr@ocf.berkeley.edu>. 19 * along with this program; if not, write to the Free Software
20 Extensions by David MacKenzie <djm@gnu.ai.mit.edu>. 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 tail -f for multiple files by Ian Lance Taylor <ian@airs.com>. 21 *
22 22 */
23 Rewrote the option parser, removed locales support,
24 and generally busyboxed, Erik Andersen <andersen@lineo.com>
25
26 Removed superfluous options and associated code ("-c", "-n", "-q").
27 Removed "tail -f" support for multiple files.
28 Both changes by Friedrich Vedder <fwv@myrtle.lahn.de>.
29 23
30 Compleate Rewrite to correctly support "-NUM", "+NUM", and "-s" by 24#include "busybox.h"
31 E.Allen Soard (esp@espsw.net).
32 25
33 */
34#include <sys/types.h> 26#include <sys/types.h>
35#include <fcntl.h> 27#include <fcntl.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <unistd.h>
39#include <string.h>
40#include <getopt.h>
41#include "busybox.h"
42
43#define STDIN "standard input"
44#define LINES 0
45#define BYTES 1
46
47static int n_files = 0;
48static char **files = NULL;
49static char * buffer;
50static ssize_t bytes_read=0;
51static ssize_t bs;
52static ssize_t filelocation=0;
53static char pip;
54
55#ifdef BB_FEATURE_SIMPLE_TAIL
56static const char unit_type=LINES;
57#else
58static char unit_type=LINES;
59static char verbose = 0;
60#endif
61
62static off_t units=0;
63 28
64static struct suffix_mult tail_suffixes[] = { 29static struct suffix_mult tail_suffixes[] = {
65 { "b", 512 }, 30 { "b", 512 },
@@ -68,232 +33,217 @@ static struct suffix_mult tail_suffixes[] = {
68 { NULL, 0 } 33 { NULL, 0 }
69}; 34};
70 35
71static int tail_stream(int fd)
72{
73 ssize_t startpoint;
74 ssize_t endpoint=0;
75 ssize_t count=0;
76 ssize_t filesize=0;
77 int direction=1;
78
79 filelocation=0;
80 startpoint=bs=BUFSIZ;
81
82 filesize=lseek(fd, -1, SEEK_END)+1;
83 pip=(filesize<=0);
84
85 if(units>=0)
86 lseek(fd,0,SEEK_SET);
87 else {
88 direction=-1;
89 count=1;
90 }
91 while(units != 0) {
92 if (pip) {
93 char * line;
94 ssize_t f_size=0;
95
96 bs=BUFSIZ;
97 line=xmalloc(bs);
98 while(1) {
99 bytes_read=read(fd,line,bs);
100 if(bytes_read<=0)
101 break;
102 buffer=xrealloc(buffer,f_size+bytes_read);
103 memcpy(&buffer[f_size],line,bytes_read);
104 filelocation=f_size+=bytes_read;
105 }
106 bs=f_size;
107 if(direction<0)
108 bs--;
109 if (line)
110 free(line);
111 } else {
112 filelocation = lseek(fd, 0, SEEK_CUR);
113 if(direction<0) {
114 if(filelocation<bs)
115 bs=filelocation;
116 filelocation = lseek(fd, -bs, SEEK_CUR);
117 }
118 bytes_read = read(fd, buffer, bs);
119 if (bytes_read <= 0)
120 break;
121 bs=bytes_read;
122 }
123 startpoint=bs;
124 if(direction>0) {
125 endpoint=startpoint;
126 startpoint=0;
127 }
128 for(;startpoint!=endpoint;startpoint+=direction) {
129#ifndef BB_FEATURE_SIMPLE_TAIL 36#ifndef BB_FEATURE_SIMPLE_TAIL
130 if(unit_type==BYTES) 37static struct suffix_mult null_suffixes[] = {
131 count++; 38 { NULL, 0 }
132 else 39};
133#endif 40#endif
134 if(buffer[startpoint-1]=='\n')
135 count++;
136 if (!pip)
137 filelocation=lseek(fd,0,SEEK_CUR);
138 if(count==units*direction)
139 break;
140 }
141 if((count==units*direction) | pip)
142 break;
143 if(direction<0){
144 filelocation = lseek(fd, -bytes_read, SEEK_CUR);
145 if(filelocation==0)
146 break;
147 }
148 }
149 if(pip && (direction<0))
150 bs++;
151 bytes_read=bs-startpoint;
152 memcpy(&buffer[0],&buffer[startpoint],bytes_read);
153 41
154 return 0; 42#define BYTES 0
43#define LINES 1
44
45static char *tailbuf;
46static int taillen;
47static int newline;
48
49void tailbuf_append(char *buf, int len)
50{
51 tailbuf = xrealloc(tailbuf, taillen + len);
52 memcpy(tailbuf + taillen, buf, len);
53 taillen += len;
155} 54}
156 55
157void add_file(char *name) 56void tailbuf_trunc()
158{ 57{
159 ++n_files; 58 char *s;
160 files = xrealloc(files, n_files); 59 s = memchr(tailbuf, '\n', taillen);
161 files[n_files - 1] = (char *) xmalloc(strlen(name) + 1); 60 memmove(tailbuf, s + 1, taillen - ((s + 1) - tailbuf));
162 strcpy(files[n_files - 1], name); 61 taillen -= (s + 1) - tailbuf;
62 newline = 0;
163} 63}
164 64
165int tail_main(int argc, char **argv) 65int tail_main(int argc, char **argv)
166{ 66{
167 int show_headers = 1; 67 int from_top = 0, units = LINES, count = 10, sleep_period = 1;
168 int test; 68 int show_headers = 0, hide_headers = 0, follow = 0;
169 int opt; 69 int *fds, nfiles = 0, status = EXIT_SUCCESS, nread, nwrite, seen = 0;
170 char follow=0; 70 char *s, *start, *end, buf[BUFSIZ];
171 int sleep_int=1; 71 int i, opt;
172 int *fd;
173
174 opterr = 0;
175
176 while ((opt=getopt(argc,argv,"c:fhn:s:q:v")) >0) {
177 72
73 while ((opt = getopt(argc, argv, "c:fhn:q:s:v")) > 0) {
178 switch (opt) { 74 switch (opt) {
75 case 'f':
76 follow = 1;
77 break;
179#ifndef BB_FEATURE_SIMPLE_TAIL 78#ifndef BB_FEATURE_SIMPLE_TAIL
180 case 'q': 79 case 'c':
181 show_headers = 0; 80 units = BYTES;
182 break; 81 /* FALLS THROUGH */
183 case 's':
184 sleep_int = atoi(optarg);
185 if(sleep_int<1)
186 sleep_int=1;
187 break;
188 case 'v':
189 verbose = 1;
190 break;
191 case 'c':
192 unit_type = BYTES;
193 /* FALLS THROUGH */
194#endif 82#endif
195 case 'n': 83 case 'n':
196 test = parse_number(optarg, tail_suffixes); 84 count = parse_number(optarg, tail_suffixes);
197 if (test) { 85 if (count < 0)
86 count = -count;
198 if (optarg[0] == '+') 87 if (optarg[0] == '+')
199 units = test; 88 from_top = 1;
200 else 89 break;
201 units = -(test+1); 90#ifndef BB_FEATURE_SIMPLE_TAIL
202 } else 91 case 'q':
92 hide_headers = 1;
93 break;
94 case 's':
95 sleep_period = parse_number(optarg, null_suffixes);
96 break;
97 case 'v':
98 show_headers = 1;
99 break;
100#endif
101 default:
203 usage(tail_usage); 102 usage(tail_usage);
204 break;
205 case 'f':
206 follow = 1;
207 break;
208 default:
209 usage(tail_usage);
210 } 103 }
211 } 104 }
212 while (optind <= argc) { 105
213 if(optind==argc) { 106 /* open all the files */
214 if (n_files==0) 107 fds = (int *)xmalloc(sizeof(int) * (argc - optind + 1));
215 add_file(STDIN); 108 if (argc == optind) {
216 else 109 fds[nfiles++] = STDIN_FILENO;
217 break; 110 argv[optind] = "standard input";
218 }else { 111 } else {
219 if (!strcmp(argv[optind], "-")) { 112 for (i = optind; i < argc; i++) {
220 add_file(STDIN); 113 if (strcmp(argv[i], "-") == 0) {
221 } else { 114 fds[nfiles++] = STDIN_FILENO;
222 add_file(argv[optind]); 115 argv[i] = "standard input";
116 } else if ((fds[nfiles++] = open(argv[i], O_RDONLY)) < 0) {
117 perror_msg("%s", argv[i]);
118 status = EXIT_FAILURE;
223 } 119 }
224 optind++;
225 } 120 }
226 } 121 }
227 if(units==0) 122
228 units=-11;
229 if(units>0)
230 units--;
231 fd=xmalloc(sizeof(int)*n_files);
232 if (n_files == 1)
233#ifndef BB_FEATURE_SIMPLE_TAIL 123#ifndef BB_FEATURE_SIMPLE_TAIL
234 if (!verbose) 124 /* tail the files */
125 if (!from_top && units == BYTES)
126 tailbuf = xmalloc(count);
235#endif 127#endif
236 show_headers = 0;
237 buffer=xmalloc(BUFSIZ);
238 for (test = 0; test < n_files; test++) {
239 if (show_headers)
240 printf("==> %s <==\n", files[test]);
241 if (!strcmp(files[test], STDIN))
242 fd[test] = 0;
243 else
244 fd[test] = open(files[test], O_RDONLY);
245 if (fd[test] == -1)
246 error_msg_and_die("Unable to open file %s.\n", files[test]);
247 tail_stream(fd[test]);
248 128
249 bs=BUFSIZ; 129 for (i = 0; i < nfiles; i++) {
250 while (1) { 130 if (fds[i] == -1)
251 if((filelocation>0 || pip)){ 131 continue;
252 write(1,buffer,bytes_read); 132 seen = 0;
133 if (show_headers || (!hide_headers && nfiles > 1))
134 printf("%s==> %s <==\n", i == 0 ? "" : "\n", argv[optind + i]);
135 while ((nread = safe_read(fds[i], buf, sizeof(buf))) > 0) {
136 if (from_top) {
137#ifndef BB_FEATURE_SIMPLE_TAIL
138 if (units == BYTES) {
139 if (count - 1 <= seen)
140 nwrite = nread;
141 else if (count - 1 <= seen + nread)
142 nwrite = nread + seen - (count - 1);
143 else
144 nwrite = 0;
145 seen += nread;
146 } else {
147#else
148 {
149#endif
150 if (count - 1 <= seen)
151 nwrite = nread;
152 else {
153 nwrite = 0;
154 for (s = memchr(buf, '\n', nread); s != NULL;
155 s = memchr(s+1, '\n', nread - (s + 1 - buf))) {
156 if (count - 1 <= ++seen) {
157 nwrite = nread - (s + 1 - buf);
158 break;
159 }
160 }
161 }
162 }
163 if (full_write(STDOUT_FILENO, buf + nread - nwrite,
164 nwrite) < 0) {
165 perror_msg("write");
166 status = EXIT_FAILURE;
167 break;
168 }
169 } else {
170#ifndef BB_FEATURE_SIMPLE_TAIL
171 if (units == BYTES) {
172 if (nread < count) {
173 memmove(tailbuf, tailbuf + nread, count - nread);
174 memcpy(tailbuf + count - nread, buf, nread);
175 } else {
176 memcpy(tailbuf, buf + nread - count, count);
177 }
178 seen += nread;
179 } else {
180#else
181 {
182#endif
183 for (start = buf, end = memchr(buf, '\n', nread);
184 end != NULL; start = end+1,
185 end = memchr(start, '\n', nread - (start - buf))) {
186 if (newline && count <= seen)
187 tailbuf_trunc();
188 tailbuf_append(start, end - start + 1);
189 seen++;
190 newline = 1;
191 }
192 if (newline && count <= seen && nread - (start - buf) > 0)
193 tailbuf_trunc();
194 tailbuf_append(start, nread - (start - buf));
195 }
253 } 196 }
254 bytes_read = read(fd[test], buffer, bs); 197 }
255 filelocation+=bytes_read; 198
256 if (bytes_read <= 0) { 199 if (nread < 0) {
257 break; 200 perror_msg("read");
201 status = EXIT_FAILURE;
202 }
203
204#ifndef BB_FEATURE_SIMPLE_TAIL
205 if (!from_top && units == BYTES) {
206 if (count < seen)
207 seen = count;
208 if (full_write(STDOUT_FILENO, tailbuf + count - seen, seen) < 0) {
209 perror_msg("write");
210 status = EXIT_FAILURE;
258 } 211 }
259 usleep(sleep_int * 1000);
260 } 212 }
261 if(n_files>1) 213#endif
262 printf("\n"); 214
215 if (!from_top && units == LINES) {
216 if (full_write(STDOUT_FILENO, tailbuf, taillen) < 0) {
217 perror_msg("write");
218 status = EXIT_FAILURE;
219 }
220 }
221
222 taillen = 0;
263 } 223 }
264 while(1){ 224
265 for (test = 0; test < n_files; test++) { 225 while (follow) {
266 if(!follow){ 226 sleep(sleep_period);
267 close(fd[test]); 227
228 for (i = 0; i < nfiles; i++) {
229 if (fds[i] == -1)
268 continue; 230 continue;
269 } else { 231
270 sleep(sleep_int); 232 if ((nread = safe_read(fds[i], buf, sizeof(buf))) > 0) {
271 bytes_read = read(fd[test], buffer, bs); 233 if (show_headers || (!hide_headers && nfiles > 1))
272 if(bytes_read>0) { 234 printf("\n==> %s <==\n", argv[optind + i]);
273 if (show_headers) 235
274 printf("==> %s <==\n", files[test]); 236 do {
275 write(1,buffer,bytes_read); 237 full_write(STDOUT_FILENO, buf, nread);
276 if(n_files>1) 238 } while ((nread = safe_read(fds[i], buf, sizeof(buf))) > 0);
277 printf("\n"); 239 }
278 } 240
241 if (nread < 0) {
242 perror_msg("read");
243 status = EXIT_FAILURE;
279 } 244 }
280 } 245 }
281 if(!follow)
282 break;
283 } 246 }
284 if (fd)
285 free(fd);
286 if (buffer)
287 free(buffer);
288 if(files)
289 free(files);
290 return 0;
291}
292 247
293/* 248 return status;
294Local Variables: 249}
295c-file-style: "linux"
296c-basic-offset: 4
297tab-width: 4
298End:
299*/
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