diff options
| -rw-r--r-- | coreutils/tail.c | 136 |
1 files changed, 48 insertions, 88 deletions
diff --git a/coreutils/tail.c b/coreutils/tail.c index b690b370e..a753a10b7 100644 --- a/coreutils/tail.c +++ b/coreutils/tail.c @@ -29,44 +29,30 @@ static const struct suffix_mult tail_suffixes[] = { { "b", 512 }, { "k", 1024 }, - { "m", 1048576 }, + { "m", 1024*1024 }, { NULL, 0 } }; static int status; -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 (full_write(STDOUT_FILENO, buf, len) < 0) - bb_perror_nomsg_and_die(); -} - static void tail_xprint_header(const char *fmt, const char *filename) { -#if defined __GLIBC__ - if (dprintf(STDOUT_FILENO, fmt, filename) < 0) { + if (fdprintf(STDOUT_FILENO, fmt, filename) < 0) bb_perror_nomsg_and_die(); - } -#else - int hdr_len = strlen(fmt) + strlen(filename); - char *hdr = xzalloc(hdr_len); - sprintf(hdr, filename, filename); - tail_xbb_full_write(hdr, hdr_len); -#endif } static ssize_t tail_read(int fd, char *buf, size_t count) { ssize_t r; - off_t current,end; + 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) { + r = safe_read(fd, buf, count); + if (r < 0) { bb_perror_msg(bb_msg_read_error); status = EXIT_FAILURE; } @@ -74,82 +60,55 @@ static ssize_t tail_read(int fd, char *buf, size_t count) 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) { - long count = 10; + unsigned count = 10; unsigned sleep_period = 1; int from_top = 0; - int follow = 0; int header_threshhold = 1; - int count_bytes = 0; + 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, nfiles, nread, nwrite, seen, i, opt; + int *fds; char *s, *buf; const char *fmt; + void eat_num(const char *p) { + if (*p == '-') p++; + else if (*p == '+') { p++; from_top = 1; } + count = xatou_sfx(p, tail_suffixes); + } + + #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]) ) { - optind = 2; - optarg = argv[1]; - goto GET_COUNT; + argv[0] = "-n"; + argv--; + argc++; } #endif - while ((opt = getopt(argc, argv, tail_opts)) > 0) { - switch (opt) { - case 'f': - follow = 1; - break; - case 'c': - count_bytes = 1; - /* FALLS THROUGH */ - case 'n': -#if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_TAIL - GET_COUNT: -#endif - from_top = 0; - if (*optarg == '+') { - ++optarg; - from_top = 1; - } - count = xatol_sfx(optarg, tail_suffixes); - /* Note: Leading whitespace is an error trapped above. */ - if (count < 0) { - count = -count; - } - break; + 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) eat_num(str_c); // -c + if (opt & 0x4) eat_num(str_n); // -n #if ENABLE_FEATURE_FANCY_TAIL - case 'q': - header_threshhold = INT_MAX; - break; - case 's': - sleep_period = xatou(optarg); - break; - case 'v': - header_threshhold = 0; - break; + 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 - default: - bb_show_usage(); - } - } argc -= optind; argv += optind; @@ -160,34 +119,35 @@ int tail_main(int argc, char **argv) struct stat statbuf; if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) { - follow = 0; + opt &= ~1; /* clear FOLLOW */ } *argv = (char *) bb_msg_standard_input; goto DO_STDIN; } do { - if (LONE_DASH(argv[i])) { - DO_STDIN: + 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; - } else if ((fds[nfiles] = open(argv[i], O_RDONLY)) < 0) { - bb_perror_msg("%s", argv[i]); - status = EXIT_FAILURE; - continue; } argv[nfiles] = argv[i]; ++nfiles; } while (++i < argc); - if (!nfiles) { + if (!nfiles) bb_error_msg_and_die("no files"); - } 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 (!from_top && COUNT_BYTES) { if (tailbufsize < count) { tailbufsize = count + BUFSIZ; } @@ -203,7 +163,7 @@ int tail_main(int argc, char **argv) * 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)) { + if (!(count|from_top) && lseek(fds[i], 0, SEEK_END) >= 0) { continue; } @@ -221,22 +181,22 @@ int tail_main(int argc, char **argv) if (from_top) { nwrite = nread; if (seen < count) { - if (count_bytes) { + if (COUNT_BYTES) { nwrite -= (count - seen); seen = count; } else { s = buf; do { --nwrite; - if ((*s++ == '\n') && (++seen == count)) { + if (*s++ == '\n' && ++seen == count) { break; } } while (nwrite); } } - tail_xbb_full_write(buf + nread - nwrite, nwrite); + xwrite(STDOUT_FILENO, buf + nread - nwrite, nwrite); } else if (count) { - if (count_bytes) { + if (COUNT_BYTES) { taillen += nread; if (taillen > count) { memmove(tailbuf, tailbuf + taillen - count, count); @@ -286,7 +246,7 @@ int tail_main(int argc, char **argv) } if (!from_top) { - tail_xbb_full_write(tailbuf, taillen); + xwrite(STDOUT_FILENO, tailbuf, taillen); } taillen = 0; @@ -296,7 +256,7 @@ int tail_main(int argc, char **argv) fmt = NULL; - while (follow) { + if (FOLLOW) while (1) { sleep(sleep_period); i = 0; do { @@ -308,7 +268,7 @@ int tail_main(int argc, char **argv) tail_xprint_header(fmt, argv[i]); fmt = NULL; } - tail_xbb_full_write(buf, nread); + xwrite(STDOUT_FILENO, buf, nread); } } while (++i < nfiles); } |