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-rw-r--r--i/pc104/initrd/conf/busybox/coreutils/tail.c278
1 files changed, 278 insertions, 0 deletions
diff --git a/i/pc104/initrd/conf/busybox/coreutils/tail.c b/i/pc104/initrd/conf/busybox/coreutils/tail.c
new file mode 100644
index 0000000..52bacb7
--- /dev/null
+++ b/i/pc104/initrd/conf/busybox/coreutils/tail.c
@@ -0,0 +1,278 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * 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.
+ */
+
+/* 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 "busybox.h"
+
+static const struct suffix_mult tail_suffixes[] = {
+ { "b", 512 },
+ { "k", 1024 },
+ { "m", 1024*1024 },
+ { NULL, 0 }
+};
+
+static int status;
+
+static void tail_xprint_header(const char *fmt, const char *filename)
+{
+ if (fdprintf(STDOUT_FILENO, fmt, filename) < 0)
+ bb_perror_nomsg_and_die();
+}
+
+static ssize_t tail_read(int fd, char *buf, size_t count)
+{
+ 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);
+ r = safe_read(fd, buf, count);
+ if (r < 0) {
+ bb_perror_msg(bb_msg_read_error);
+ status = EXIT_FAILURE;
+ }
+
+ return r;
+}
+
+static const char header_fmt[] = "\n==> %s <==\n";
+
+static unsigned eat_num(const char *p) {
+ if (*p == '-') p++;
+ else if (*p == '+') { p++; status = 1; }
+ return xatou_sfx(p, tail_suffixes);
+}
+
+int tail_main(int argc, char **argv);
+int tail_main(int argc, char **argv)
+{
+ unsigned count = 10;
+ unsigned sleep_period = 1;
+ bool from_top;
+ int header_threshhold = 1;
+ const char *str_c, *str_n, *str_s;
+
+ char *tailbuf;
+ size_t tailbufsize;
+ int taillen = 0;
+ int newline = 0;
+ int nfiles, nread, nwrite, seen, i, opt;
+
+ int *fds;
+ char *s, *buf;
+ const char *fmt;
+
+#if ENABLE_INCLUDE_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])
+ ) {
+ argv[0] = (char*)"-n";
+ argv--;
+ argc++;
+ }
+#endif
+
+ opt = getopt32(argc, argv, "fc:n:" USE_FEATURE_FANCY_TAIL("qs:v"), &str_c, &str_n, &str_s);
+#define FOLLOW (opt & 0x1)
+#define COUNT_BYTES (opt & 0x2)
+ //if (opt & 0x1) // -f
+ if (opt & 0x2) count = eat_num(str_c); // -c
+ if (opt & 0x4) count = eat_num(str_n); // -n
+#if ENABLE_FEATURE_FANCY_TAIL
+ if (opt & 0x8) header_threshhold = INT_MAX; // -q
+ if (opt & 0x10) sleep_period = xatou(str_s); // -s
+ if (opt & 0x20) header_threshhold = 0; // -v
+#endif
+ argc -= optind;
+ argv += optind;
+ from_top = status;
+
+ /* open all the files */
+ fds = xmalloc(sizeof(int) * (argc + 1));
+ status = nfiles = i = 0;
+ if (argc == 0) {
+ struct stat statbuf;
+
+ if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) {
+ opt &= ~1; /* clear FOLLOW */
+ }
+ *argv = (char *) bb_msg_standard_input;
+ goto DO_STDIN;
+ }
+
+ do {
+ if (NOT_LONE_DASH(argv[i])) {
+ fds[nfiles] = open(argv[i], O_RDONLY);
+ if (fds[nfiles] < 0) {
+ bb_perror_msg("%s", argv[i]);
+ status = EXIT_FAILURE;
+ continue;
+ }
+ } else {
+ DO_STDIN: /* "-" */
+ fds[nfiles] = STDIN_FILENO;
+ }
+ argv[nfiles] = argv[i];
+ ++nfiles;
+ } while (++i < argc);
+
+ if (!nfiles)
+ bb_error_msg_and_die("no files");
+
+ tailbufsize = BUFSIZ;
+
+ /* tail the files */
+ if (!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);
+ }
+ }
+ xwrite(STDOUT_FILENO, 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 (!from_top) {
+ xwrite(STDOUT_FILENO, tailbuf, taillen);
+ }
+
+ taillen = 0;
+ } while (++i < nfiles);
+
+ buf = xrealloc(tailbuf, BUFSIZ);
+
+ fmt = NULL;
+
+ if (FOLLOW) while (1) {
+ 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;
+ }
+ xwrite(STDOUT_FILENO, buf, nread);
+ }
+ } while (++i < nfiles);
+ }
+
+ return status;
+}