diff options
Diffstat (limited to 'toys/posix')
| -rw-r--r-- | toys/posix/tail.c | 138 |
1 files changed, 63 insertions, 75 deletions
diff --git a/toys/posix/tail.c b/toys/posix/tail.c index 842814c0..98309c0f 100644 --- a/toys/posix/tail.c +++ b/toys/posix/tail.c @@ -6,7 +6,7 @@ * * Deviations from posix: -f waits for pipe/fifo on stdin (nonblock?). -USE_TAIL(NEWTOY(tail, "?fFs#=1c-n-[-cn][-fF]", TOYFLAG_USR|TOYFLAG_BIN)) +USE_TAIL(NEWTOY(tail, "?fFs:c-n-[-cn][-fF]", TOYFLAG_USR|TOYFLAG_BIN)) config TAIL bool "tail" @@ -27,18 +27,18 @@ config TAIL #define FOR_tail #include "toys.h" -struct follow_file { - char *path; - int fd; - dev_t dev; - ino_t ino; -}; - GLOBALS( - long n, c, s; - int file_no, last_fd; + long n, c; + char *s; + + int file_no, last_fd, ss; struct xnotify *not; - struct follow_file *F; + struct { + char *path; + int fd; + dev_t dev; + ino_t ino; + } *F; ) struct line_list { @@ -132,66 +132,53 @@ static int try_lseek(int fd, long bytes, long lines) return 1; } -static void show_new(int fd, char *path) -{ - int len; - - while ((len = read(fd, toybuf, sizeof(toybuf)))>0) { - if (TT.last_fd != fd) { - TT.last_fd = fd; - xprintf("\n==> %s <==\n", path); - } - xwrite(1, toybuf, len); - } -} - -static void tail_F() +// For -f and -F +static void tail_continue() { + long long pos; + char *path; struct stat sb; - int i, old_fd; - - for (;;) { - for (i = 0; i<TT.file_no; ++i) { - old_fd = TT.F[i].fd; - if (stat(TT.F[i].path, &sb) != 0) { - if (old_fd >= 0) { - xprintf("tail: file inaccessible: %s\n", TT.F[i].path); - close(old_fd); + int i = 0, fd, len; + + for (i = 0; ; i++) { + if (FLAG(f)) fd = xnotify_wait(TT.not, &path); + else { + if (i == TT.file_no) { + i = 0; + msleep(TT.ss); + } + fd = TT.F[i].fd; + path = TT.F[i].path; + + if (stat(TT.F[i].path, &sb)) { + if (fd >= 0) { + close(fd); TT.F[i].fd = -1; + error_msg("file inaccessible: %s\n", TT.F[i].path); } continue; } - if (old_fd < 0 || sb.st_dev != TT.F[i].dev || sb.st_ino != TT.F[i].ino) { - if (old_fd >= 0) close(old_fd); - TT.F[i].fd = open(TT.F[i].path, O_RDONLY); - if (TT.F[i].fd == -1) continue; - else { - xprintf("tail: following new file: %s\n", TT.F[i].path); - TT.F[i].dev = sb.st_dev; - TT.F[i].ino = sb.st_ino; - } - } else if (sb.st_size && sb.st_size < lseek(TT.F[i].fd, 0, SEEK_CUR)) { - // If file was truncated, move to start. - xprintf("tail: file truncated: %s\n", TT.F[i].path); - xlseek(TT.F[i].fd, 0, SEEK_SET); + if (fd<0 || sb.st_dev!=TT.F[i].dev || sb.st_ino!=TT.F[i].ino) { + if (fd>=0) close(fd); + if (-1 == (TT.F[i].fd = fd = open(path, O_RDONLY))) continue; + error_msg("following new file: %s\n", path); + TT.F[i].dev = sb.st_dev; + TT.F[i].ino = sb.st_ino; + } else if (sb.st_size <= (pos = lseek(fd, 0, SEEK_CUR))) { + if (pos == sb.st_size) continue; + error_msg("file truncated: %s\n", path); + lseek(fd, 0, SEEK_SET); } - - show_new(TT.F[i].fd, TT.F[i].path); } - sleep(TT.s); - } -} - -static void tail_f() -{ - char *path; - int fd; - - for (;;) { - fd = xnotify_wait(TT.not, &path); - show_new(fd, path); + while ((len = read(fd, toybuf, sizeof(toybuf)))>0) { + if (TT.file_no>1 && TT.last_fd != fd) { + TT.last_fd = fd; + xprintf("\n==> %s <==\n", path); + } + xwrite(1, toybuf, len); + } } } @@ -201,6 +188,7 @@ static void do_tail(int fd, char *name) long bytes = TT.c, lines = TT.n; int linepop = 1; + if (fd == -1 && !FLAG(F)) return; if (FLAG(f) || FLAG(F)) { char *s = name; struct stat sb; @@ -209,11 +197,13 @@ static void do_tail(int fd, char *name) if (FLAG(f)) xnotify_add(TT.not, fd, s); if (FLAG(F)) { - if (fstat(fd, &sb) != 0) perror_exit("%s", name); + if (fd != -1) { + if (fstat(fd, &sb)) perror_exit("%s", name); + TT.F[TT.file_no].dev = sb.st_dev; + TT.F[TT.file_no].ino = sb.st_ino; + } TT.F[TT.file_no].fd = fd; TT.F[TT.file_no].path = s; - TT.F[TT.file_no].dev = sb.st_dev; - TT.F[TT.file_no].ino = sb.st_ino; } } @@ -298,23 +288,21 @@ void tail_main(void) if (!FLAG(n) && !FLAG(c)) { char *arg = *args; - // handle old "-42" style arguments + // handle old "-42" style arguments, else default to last 10 lines if (arg && *arg == '-' && arg[1]) { TT.n = atolx(*(args++)); toys.optc--; - } else { - // if nothing specified, default -n to -10 - TT.n = -10; - } + } else TT.n = -10; } - if (FLAG(F)) TT.F = xmalloc(toys.optc * sizeof(struct follow_file)); + if (FLAG(F)) TT.F = xzalloc(toys.optc*sizeof(*TT.F)); else if (FLAG(f)) TT.not = xnotify_init(toys.optc); + TT.ss = TT.s ? xparsemillitime(TT.s) : 1000; - loopfiles_rw(args, O_RDONLY|WARN_ONLY|(O_CLOEXEC*!(FLAG(f) || FLAG(F))), 0, do_tail); + loopfiles_rw(args, + O_RDONLY|WARN_ONLY|LOOPFILES_ANYWAY|(O_CLOEXEC*!(FLAG(f) || FLAG(F))), + 0, do_tail); - if (TT.file_no) { - if (FLAG(F)) tail_F(); - else if (FLAG(f)) tail_f(); - } + // Wait for more data when following files + if (TT.file_no && (FLAG(F) || FLAG(f))) tail_continue(); } |