Diff of /trunk/mkinitrd-magellan/busybox/coreutils/tail.c

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	revision 532 by niro, Sat Sep 1 22:45:15 2007 UTC	revision 816 by niro, Fri Apr 24 18:33:46 2009 UTC
#	Line 24	Line 24
24	* 7) lseek attempted when count==0 even if arg was +0 (from top)	* 7) lseek attempted when count==0 even if arg was +0 (from top)
25	*/	*/
26
27	#include "busybox.h"	#include "libbb.h"
28
29	static const struct suffix_mult tail_suffixes[] = {	static const struct suffix_mult tail_suffixes[] = {
30	{ "b", 512 },	{ "b", 512 },
31	{ "k", 1024 },	{ "k", 1024 },
32	{ "m", 1024*1024 },	{ "m", 1024*1024 },
33	{ NULL, 0 }	{ }
34	};	};
35
36	static int status;	struct globals {
37		bool status;
38		};
39		#define G (*(struct globals*)&bb_common_bufsiz1)
40
41	static void tail_xprint_header(const char *fmt, const char *filename)	static void tail_xprint_header(const char *fmt, const char *filename)
42	{	{
#	Line 44  static void tail_xprint_header(const cha	Line 47  static void tail_xprint_header(const cha
47	static ssize_t tail_read(int fd, char *buf, size_t count)	static ssize_t tail_read(int fd, char *buf, size_t count)
48	{	{
49	ssize_t r;	ssize_t r;
50	off_t current, end;	off_t current;
51	struct stat sbuf;	struct stat sbuf;
52
53	end = current = lseek(fd, 0, SEEK_CUR);	/* (A good comment is missing here) */
54	if (!fstat(fd, &sbuf))	current = lseek(fd, 0, SEEK_CUR);
55	end = sbuf.st_size;	/* /proc files report zero st_size, don't lseek them. */
56	lseek(fd, end < current ? 0 : current, SEEK_SET);	if (fstat(fd, &sbuf) == 0 && sbuf.st_size)
57	r = safe_read(fd, buf, count);	if (sbuf.st_size < current)
58		lseek(fd, 0, SEEK_SET);
59
60		r = full_read(fd, buf, count);
61	if (r < 0) {	if (r < 0) {
62	bb_perror_msg(bb_msg_read_error);	bb_perror_msg(bb_msg_read_error);
63	status = EXIT_FAILURE;	G.status = EXIT_FAILURE;
64	}	}
65
66	return r;	return r;
67	}	}
68
69	static const char header_fmt[] = "\n==> %s <==\n";	static const char header_fmt[] ALIGN1 = "\n==> %s <==\n";
70
71		static unsigned eat_num(const char *p)
72		{
73		if (*p == '-')
74		p++;
75		else if (*p == '+') {
76		p++;
77		G.status = 1; /* mark that we saw "+" */
78		}
79		return xatou_sfx(p, tail_suffixes);
80		}
81
82		int tail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
83	int tail_main(int argc, char **argv)	int tail_main(int argc, char **argv)
84	{	{
85	unsigned count = 10;	unsigned count = 10;
86	unsigned sleep_period = 1;	unsigned sleep_period = 1;
87	int from_top = 0;	bool from_top;
88	int header_threshhold = 1;	int header_threshhold = 1;
89	const char *str_c, *str_n, *str_s;	const char *str_c, *str_n;
90
91	char *tailbuf;	char *tailbuf;
92	size_t tailbufsize;	size_t tailbufsize;
93	int taillen = 0;	int taillen = 0;
94	int newline = 0;	int newlines_seen = 0;
95	int nfiles, nread, nwrite, seen, i, opt;	int nfiles, nread, nwrite, i, opt;
96		unsigned seen;
97
98	int *fds;	int *fds;
99	char *s, *buf;	char *s, *buf;
100	const char *fmt;	const char *fmt;
101
	void eat_num(const char *p) {
	if (*p == '-') p++;
	else if (*p == '+') { p++; from_top = 1; }
	count = xatou_sfx(p, tail_suffixes);
	}
102	#if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_TAIL	#if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_TAIL
103	/* Allow legacy syntax of an initial numeric option without -n. */	/* Allow legacy syntax of an initial numeric option without -n. */
104	if (argc >= 2 && (argv[1][0] == '+' || argv[1][0] == '-')	if (argv[1] && (argv[1][0] == '+' || argv[1][0] == '-')
105	&& isdigit(argv[1][1])	&& isdigit(argv[1][1])
106	) {	) {
107	argv[0] = "-n";	count = eat_num(argv[1]);
108	argv--;	argv++;
109	argc++;	argc--;
110	}	}
111	#endif	#endif
112
113	opt = getopt32(argc, argv, "fc:n:" USE_FEATURE_FANCY_TAIL("qs:v"), &str_c, &str_n, &str_s);	USE_FEATURE_FANCY_TAIL(opt_complementary = "s+";) /* -s N */
114		opt = getopt32(argv, "fc:n:" USE_FEATURE_FANCY_TAIL("qs:v"),
115		&str_c, &str_n USE_FEATURE_FANCY_TAIL(,&sleep_period));
116	#define FOLLOW (opt & 0x1)	#define FOLLOW (opt & 0x1)
117	#define COUNT_BYTES (opt & 0x2)	#define COUNT_BYTES (opt & 0x2)
118	//if (opt & 0x1) // -f	//if (opt & 0x1) // -f
119	if (opt & 0x2) eat_num(str_c); // -c	if (opt & 0x2) count = eat_num(str_c); // -c
120	if (opt & 0x4) eat_num(str_n); // -n	if (opt & 0x4) count = eat_num(str_n); // -n
121	#if ENABLE_FEATURE_FANCY_TAIL	#if ENABLE_FEATURE_FANCY_TAIL
122	if (opt & 0x8) header_threshhold = INT_MAX; // -q	if (opt & 0x8) header_threshhold = INT_MAX; // -q
	if (opt & 0x10) sleep_period = xatou(str_s); // -s
123	if (opt & 0x20) header_threshhold = 0; // -v	if (opt & 0x20) header_threshhold = 0; // -v
124	#endif	#endif
125	argc -= optind;	argc -= optind;
126	argv += optind;	argv += optind;
127		from_top = G.status; /* 1 if there was "-c +N" or "-n +N" */
128		G.status = EXIT_SUCCESS;
129
130	/* open all the files */	/* open all the files */
131	fds = xmalloc(sizeof(int) * (argc + 1));	fds = xmalloc(sizeof(int) * (argc + 1));
132	nfiles = i = 0;	if (!argv[0]) {
	if (argc == 0) {
133	struct stat statbuf;	struct stat statbuf;
134
135	if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) {	if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) {
136	opt &= ~1; /* clear FOLLOW */	opt &= ~1; /* clear FOLLOW */
137	}	}
138	*argv = (char *) bb_msg_standard_input;	*argv = (char *) bb_msg_standard_input;
	goto DO_STDIN;
139	}	}
140		nfiles = i = 0;
141	do {	do {
142	if (NOT_LONE_DASH(argv[i])) {	int fd = open_or_warn_stdin(argv[i]);
143	fds[nfiles] = open(argv[i], O_RDONLY);	if (fd < 0) {
144	if (fds[nfiles] < 0) {	G.status = EXIT_FAILURE;
145	bb_perror_msg("%s", argv[i]);	continue;
	status = EXIT_FAILURE;
	continue;
	}
	} else {
	DO_STDIN: /* "-" */
	fds[nfiles] = STDIN_FILENO;
146	}	}
147	argv[nfiles] = argv[i];	fds[nfiles] = fd;
148	++nfiles;	argv[nfiles++] = argv[i];
149	} while (++i < argc);	} while (++i < argc);
150
151	if (!nfiles)	if (!nfiles)
152	bb_error_msg_and_die("no files");	bb_error_msg_and_die("no files");
153
154		/* prepare the buffer */
155	tailbufsize = BUFSIZ;	tailbufsize = BUFSIZ;
	/* tail the files */
156	if (!from_top && COUNT_BYTES) {	if (!from_top && COUNT_BYTES) {
157	if (tailbufsize < count) {	if (tailbufsize < count + BUFSIZ) {
158	tailbufsize = count + BUFSIZ;	tailbufsize = count + BUFSIZ;
159	}	}
160	}	}
161		tailbuf = xmalloc(tailbufsize);
162
163	buf = tailbuf = xmalloc(tailbufsize);	/* tail the files */
164	fmt = header_fmt + 1; /* Skip header leading newline on first output. */	fmt = header_fmt + 1; /* Skip header leading newline on first output. */
165	i = 0;	i = 0;
166	do {	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;
	}
167	if (nfiles > header_threshhold) {	if (nfiles > header_threshhold) {
168	tail_xprint_header(fmt, argv[i]);	tail_xprint_header(fmt, argv[i]);
169	fmt = header_fmt;	fmt = header_fmt;
170	}	}
171
172		/* Optimizing count-bytes case if the file is seekable.
173		* Beware of backing up too far.
174		* Also we exclude files with size 0 (because of /proc/xxx) */
175		if (COUNT_BYTES && !from_top) {
176		off_t current = lseek(fds[i], 0, SEEK_END);
177		if (current > 0) {
178		if (count == 0)
179		continue; /* showing zero lines is easy :) */
180		current -= count;
181		if (current < 0)
182		current = 0;
183		xlseek(fds[i], current, SEEK_SET);
184		bb_copyfd_size(fds[i], STDOUT_FILENO, count);
185		continue;
186		}
187		}
188
189	buf = tailbuf;	buf = tailbuf;
190	taillen = 0;	taillen = 0;
191	seen = 1;	seen = 1;
192	newline = 0;	newlines_seen = 0;
193	while ((nread = tail_read(fds[i], buf, tailbufsize-taillen)) > 0) {	while ((nread = tail_read(fds[i], buf, tailbufsize-taillen)) > 0) {
194	if (from_top) {	if (from_top) {
195	nwrite = nread;	nwrite = nread;
#	Line 198  int tail_main(int argc, char **argv)	Line 211  int tail_main(int argc, char **argv)
211	} else if (count) {	} else if (count) {
212	if (COUNT_BYTES) {	if (COUNT_BYTES) {
213	taillen += nread;	taillen += nread;
214	if (taillen > count) {	if (taillen > (int)count) {
215	memmove(tailbuf, tailbuf + taillen - count, count);	memmove(tailbuf, tailbuf + taillen - count, count);
216	taillen = count;	taillen = count;
217	}	}
218	} else {	} else {
219	int k = nread;	int k = nread;
220	int nbuf = 0;	int newlines_in_buf = 0;
221
222	while (k) {	do { /* count '\n' in last read */
223	--k;	k--;
224	if (buf[k] == '\n') {	if (buf[k] == '\n') {
225	++nbuf;	newlines_in_buf++;
226	}	}
227	}	} while (k);
228
229	if (newline + nbuf < count) {	if (newlines_seen + newlines_in_buf < (int)count) {
230	newline += nbuf;	newlines_seen += newlines_in_buf;
231	taillen += nread;	taillen += nread;
232	} else {	} else {
233	int extra = 0;	int extra = (buf[nread-1] != '\n');
	if (buf[nread-1] != '\n') {
	extra = 1;
	}
234
235	k = newline + nbuf + extra - count;	k = newlines_seen + newlines_in_buf + extra - count;
236	s = tailbuf;	s = tailbuf;
237	while (k) {	while (k) {
238	if (*s == '\n') {	if (*s == '\n') {
239	--k;	k--;
240	}	}
241	++s;	s++;
242	}	}
243	taillen += nread - (s - tailbuf);	taillen += nread - (s - tailbuf);
244	memmove(tailbuf, s, taillen);	memmove(tailbuf, s, taillen);
245	newline = count - extra;	newlines_seen = count - extra;
246	}	}
247	if (tailbufsize < taillen + BUFSIZ) {	if (tailbufsize < (size_t)taillen + BUFSIZ) {
248	tailbufsize = taillen + BUFSIZ;	tailbufsize = taillen + BUFSIZ;
249	tailbuf = xrealloc(tailbuf, tailbufsize);	tailbuf = xrealloc(tailbuf, tailbufsize);
250	}	}
251	}	}
252	buf = tailbuf + taillen;	buf = tailbuf + taillen;
253	}	}
254	}	} /* while (tail_read() > 0) */
255	if (!from_top) {	if (!from_top) {
256	xwrite(STDOUT_FILENO, tailbuf, taillen);	xwrite(STDOUT_FILENO, tailbuf, taillen);
257	}	}
	taillen = 0;
258	} while (++i < nfiles);	} while (++i < nfiles);
259
260	buf = xrealloc(tailbuf, BUFSIZ);	buf = xrealloc(tailbuf, BUFSIZ);
#	Line 263  int tail_main(int argc, char **argv)	Line 268  int tail_main(int argc, char **argv)
268	if (nfiles > header_threshhold) {	if (nfiles > header_threshhold) {
269	fmt = header_fmt;	fmt = header_fmt;
270	}	}
271	while ((nread = tail_read(fds[i], buf, sizeof(buf))) > 0) {	while ((nread = tail_read(fds[i], buf, BUFSIZ)) > 0) {
272	if (fmt) {	if (fmt) {
273	tail_xprint_header(fmt, argv[i]);	tail_xprint_header(fmt, argv[i]);
274	fmt = NULL;	fmt = NULL;
#	Line 272  int tail_main(int argc, char **argv)	Line 277  int tail_main(int argc, char **argv)
277	}	}
278	} while (++i < nfiles);	} while (++i < nfiles);
279	}	}
280		if (ENABLE_FEATURE_CLEAN_UP) {
281	return status;	free(fds);
282		}
283		return G.status;
284	}	}

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Legend: Removed from v.532   changed lines   Added in v.816